A fundamental step in identifying the causes of any failure is the choice of a starting point for the search. Often the reason is on the surface, but in some cases you have to work hard, conducting a little investigation. A car enthusiast who has made half a dozen random checks, replacements and corrections has a good chance of discovering the cause of the failure (or its symptom), However, this approach cannot be called reasonable in any way, due to its laboriousness and aimlessness of time and money. A calm, logical approach to finding a failed node or component is much more effective. It is imperative to take into account all the symptoms and warning signs that preceded the breakdown, sometimes minor, such as loss of engine power, changes in meter readings, the occurrence of unusual sounds and smells, etc. Keep in mind that failure of components such as fuses or spark plugs may only be a symptom of a deeper problem.
Below in this subsection, a fairly simple scheme for diagnosing the most common failures is given. The causes of violations and their symptoms are grouped according to their relationship to the functioning of a particular unit or system: "Engine", "Cooling system" etc. In parentheses are links to the relevant Chapters and Sections of the Manual that are relevant to the functioning of the components suspected of malfunctioning.
Regardless of the nature of the failure, the investigation of its cause is always based on the same basic principles:
- Make sure you identify the symptoms of rejection correctly. The foregoing means confidence in determining the boundaries of the search area, which is especially important when diagnosing a failure to another motorist who cannot adequately state the symptoms of an existing violation.
- Try not to overlook obvious violations. For example, if the engine won't start, feel free to check for fuel in the gas tank (at the same time, the statements of the owner of the faulty car should not be taken for granted). In the event of a failure of electrical equipment, first of all, you should check the condition and reliability of fastening of the terminal connections of the electrical wiring, only after that it makes sense to get diagnostic tools.
- Try to address the cause of the failure, not its symptom. Replacing a dead battery with a new one will help start the engine, but the existing cause of the discharge of the old battery will remain uncorrected, which will lead to a quick failure of the new one. Also, replacing spark plugs thrown with oil will allow you to restore the correct functioning of the engine for some time, but the failure will certainly repeat soon (if the reason lay not simply in the use of candles of the wrong type).
- Don't take any statements for granted. remember, that "new" a component can also be defective, especially if it has been in the trunk for a long time - you should not exclude a component from the list of checks just because it is new or recently installed. In case of neglecting the implementation of this recommendation, one should not be surprised when the reason for the failure, finally revealed, turns out to be lying on the surface from the very beginning.
Diagnosis of common engine failures
Engine won't crank when trying to start it
1. The battery terminals are oxidized, or the wire lugs are loose on them (see chapter Settings and ongoing maintenance).
2. Low or defective battery (see chapter Settings and ongoing maintenance).
3. Not translated into position "R" AT/CVT (see chapter Gear box), or the clutch is not fully depressed (see chapter Clutch and drive shafts).
4. The electrical wiring of the starting system circuit is broken or otherwise damaged, or the fastening of the terminals of the contact connections is loose (see chapter Engine electrical equipment or Onboard electrical equipment).
5. Starter drive gear stuck in flywheel ring gear (see chapter Engine electrical equipment).
6. The starter traction relay is out of order (see chapter Engine electrical equipment).
7. Faulty starter motor (see chapter Engine electrical equipment).
8. Faulty ignition switch (see chapter Onboard electrical equipment).
9. Broken or worn starter drive gear teeth or flywheel ring gear (see chapters Engine and Engine electrical equipment).
Engine cranks but won't start
1. Fuel tank is empty.
2. Low battery (engine cranks too slowly) (see chapter Engine electrical equipment).
3. The battery terminals are oxidized, or the wire lugs are loose on them (see chapter Settings and ongoing maintenance).
4. There are fuel leaks through the injector (s) injection, faulty fuel pump or fuel pressure regulator (see chapter Power and exhaust systems).
5. Fuel is not supplied to the fuel line (see chapter Power and exhaust systems).
6. There are other malfunctions of the fuel supply system (see chapter Power and exhaust systems).
7. Moistened or damaged components of the ignition system (see chapter Engine electrical equipment).
8. Worn or damaged spark plugs, or incorrect electrode gap setting (see chapter Settings and ongoing maintenance).
9. The electrical wiring of the starting system circuit is broken or otherwise damaged, or the fastening of the terminals of the contact connections is loose (see chapter Engine electrical equipment).
10. The setting of the ignition timing is violated due to the loosening of the distributor fastening (see chapter Engine electrical equipment).
11. The electrical wiring of the ignition system circuit is broken or otherwise damaged, the fastening of the terminals of the contact connections is loose, or the ignition coil is faulty (see chapter Engine electrical equipment).
12. Broken or worn timing belt (see chapter Engine).
13. Faulty fuel pump relay and / or wiring (see chapter Engine).
14. There is mechanical damage to the engine (e.g. camshaft drive) (see chapter Engine).
Difficulty starting a cold engine
1. Low battery (see chapter Settings and ongoing maintenance).
2. Faulty fuel supply system (see chapter Power and exhaust systems).
3. There are fuel leaks through the injector (s) injection (see chapter Power and exhaust systems).
4. There are breakdowns in the distributor as a result of the formation "coal tracks" (see chapter Engine electrical equipment)
5. Violated setting of the ignition timing (see chapter Engine electrical equipment).
6. The battery terminals are oxidized, or the wire lugs are loose on them (see chapter Settings and ongoing maintenance).
7. Worn or damaged spark plugs, or incorrect electrode gap setting (see chapter Settings and ongoing maintenance).
8. Compression pressure dropped (see chapter Engine).
Difficulty starting a hot engine
1. The filter element of the air cleaner is dirty, or its patency is otherwise impaired (see chapter Settings and ongoing maintenance).
2. Faulty fuel injection system (fuel does not reach injection injectors) (see chapter Power and exhaust systems).
3. Oxidized battery terminal connections (especially mass) (see chapter Settings and ongoing maintenance).
4. Dropped compression pressure (see chapter Engine).
5. Violated setting of the ignition timing (see chapter Engine electrical equipment).
6. Defective evaporative emission control system (EVAP) (see chapter Engine management).
Entering the starter into gear is difficult, or accompanied by extraneous noise
1. Broken or worn starter drive gear teeth or flywheel ring gear (see chapters Engine and Engine electrical equipment.
2. Loose or loose starter mounting bolts (see chapter Engine electrical equipment).
3. Worn or damaged internal starter components (see chapter Engine electrical equipment).
Engine starts but immediately stalls
1. Broken or otherwise damaged electrical wiring of the ignition circuit, or loose fastening of the terminals of the contact connections on the distributor, ignition coil or generator (see chapter Engine electrical equipment).
2. There is a fuel starvation of the injector (ov) injection (see chapters Settings and ongoing maintenance and Power and exhaust systems).
3. There are vacuum losses through the gasket between the intake manifold and the throttle body (see chapters Settings and ongoing maintenance and Power and exhaust systems).
During parking, oil leaks under the engine
1. There are leaks from the oil pan gasket or drain plug (see chapter Engine).
2. There are leaks through the seat seal of the oil pressure switch (see chapter Engine).
3. There are leaks through the cylinder head gaskets (see chapter Engine).
4. There are leaks through the engine shaft seals (see chapter Engine).
Idle speed stability is broken
1. Vacuum losses occur (see chapters Engine and Power and exhaust systems).
2. Faulty EGR valve (see chapter Engine management).
3. Blocked air cleaner element (see chapter Settings and ongoing maintenance).
4. The fuel pump does not provide the required fuel flow (see chapter Power and exhaust systems).
5. Faulty fuel pulsation damper (see chapter Power and exhaust systems).
6. The tightness of the cylinder head gasket is broken (see chapter Engine).
7. The timing belt or its gears are worn out (see chapter Engine)
8. Timing belt tension incorrectly adjusted (see chapter Engine).
9. Camshaft lobes worn out (see chapter Engine).
10. Worn or damaged spark plugs, or incorrect electrode gap setting (see chapter Settings and ongoing maintenance).
11. Compression pressure dropped or unevenly distributed between the cylinders (see chapter Engine).
12. Violated injector patency (ov) (see chapter Power and exhaust systems).
13. There are violations of the functioning of the suspension control system of the power unit (see chapter Engine).
There are misfires at idle
1. Worn or damaged spark plugs, or incorrect electrode gap setting (see chapter Settings and ongoing maintenance).
2. Faulty BB wires of spark plugs (see chapter Settings and ongoing maintenance).
3. Vacuum losses occur (see chapter Settings and ongoing maintenance).
4. Violated setting of the ignition timing (see chapter Settings and ongoing maintenance).
5. Compression pressure dropped or unevenly distributed between the cylinders (see chapter Engine).
6. Faulty fuel injection / engine management system (see chapters Power and exhaust systems and Engine management).
7. Damaged, worn or disconnected crankcase ventilation hoses (see chapter Power and exhaust systems).
8. The distributor cap is cracked, or carbon paths have formed inside it (see chapter Engine electrical equipment).
Misfire occurs while driving in gear
1. The patency of the fuel filter is broken (see chapter Settings and ongoing maintenance).
2. Fuel pressure dropped (see chapter Power and exhaust systems).
3. Worn or damaged spark plugs, or incorrect electrode gap setting (see chapter Settings and ongoing maintenance).
4. Violated setting of the ignition timing (see chapter Engine electrical equipment).
5. The distributor cover is cracked, carbon paths have formed inside it, or the fastening of the explosive wires has loosened (see chapters Settings and ongoing maintenance and Engine electrical equipment).
6. Faulty BB wires of spark plugs (see chapters Settings and ongoing maintenance and Engine electrical equipment).
7. Faulty components of systems for reducing the toxicity of exhaust gases (see chapter Engine management).
8. Compression pressure dropped or unevenly distributed between the cylinders (see chapter Engine).
9. The ignition system is faulty, or the contact connections of its electrical wiring are loose (see chapter Engine electrical equipment).
10. There is a loss of vacuum in the fuel injection system, intake manifold, air control valve or vacuum hoses (see chapters Power and exhaust systems and Engine management).
11. The fuel pump is faulty, or the pressure it develops has fallen (see chapter Power and exhaust systems).
12. The ventilation of the fuel tank is broken, or the fuel lines are blocked (see chapter Power and exhaust systems).
The stability of the engine speed is violated during acceleration
1. Worn or damaged spark plugs, or incorrect electrode gap setting (see chapter Settings and ongoing maintenance).
2. Faulty fuel injection system (see chapter Power and exhaust systems).
3. The patency of the fuel filter is broken (see chapter Power and exhaust systems).
4. Violated setting of the ignition timing (see chapter Engine electrical equipment).
5. There are air leaks in the intake tract (see chapters Engine and Power and exhaust systems).
6. Loose connector (ov) injector wiring (ov) injection (see chapter Power and exhaust systems).
7. Faulty control unit (ECU) or one of the information sensors of the engine management system (see chapter Engine management).
The engine runs jerky when the accelerator pedal is held motionless
1. There are air leaks in the intake tract (see chapters Engine and Power and exhaust systems).
2. Faulty fuel pump (see chapter Power and exhaust systems).
3. Loose connector (ov) injector wiring (ov) injection (see chapter Power and exhaust systems).
4. Faulty control unit (ECU) or one of the information sensors of the engine management system (see chapter Engine management).
The engine spontaneously stalls
1. Violated idle speed setting (see chapter Settings and ongoing maintenance).
2. The patency of the fuel filter is broken, or moisture has got into the power system (see chapters Settings and ongoing maintenance and Power and exhaust systems).
3. Moistened or damaged components of the ignition system (see chapter Engine electrical equipment).
4. Faulty components of systems for reducing the toxicity of exhaust gases (see chapter Engine management).
5. Worn or damaged spark plugs, or incorrect electrode gap setting (see chapter Settings and ongoing maintenance).
6. Faulty BB wires of spark plugs (see chapter Settings and ongoing maintenance).
7. Vacuum loss occurs at the throttle body, intake piping, or through the connecting hoses (see chapters Engine and Power and exhaust systems).
8. Violated valve clearance adjustment (see chapter Settings and ongoing maintenance).
9. The fuel pump is faulty, or the pressure it develops has fallen (see chapter Power and exhaust systems).
10. The ventilation of the fuel tank is broken, or the fuel lines are blocked (see chapter Power and exhaust systems).
Decreased engine power
1. Violated setting of the ignition timing (see chapter Engine electrical equipment).
2. Excessive distributor shaft play (see chapter Engine electrical equipment).
3. Faulty slider, distributor cap, or its electrical wiring (see chapters Settings and ongoing maintenance and Engine electrical equipment).
4. Worn or damaged spark plugs, or incorrect electrode gap setting (see chapter Settings and ongoing maintenance).
5. Faulty fuel injection system (see chapter Power and exhaust systems).
6. Faulty ignition coil (see chapter Engine electrical equipment).
7. Stuck brakes (see chapter Brake system).
8. ATF AT/CVT level dropped (see chapter Settings and ongoing maintenance).
9. Clutch slips (see chapter Clutch and drive shafts).
10. The patency of the fuel filter is broken, or moisture has got into the power system (see chapters Settings and ongoing maintenance and Power and exhaust systems).
11. Faulty exhaust emission system (see chapter Engine management).
12. Compression pressure dropped or unevenly distributed between the cylinders (see chapter Engine).
13. Blocked exhaust system (see chapter Power and exhaust systems).
14. The fuel pump is faulty, or the pressure it develops has fallen (see chapter Power and exhaust systems).
Happening "shots" in the exhaust system
1. Serviceability of functioning of system of decrease in toxicity is broken (see chapter Engine management).
2. Violated setting of the ignition timing (see chapter Engine electrical equipment).
3. There is a malfunction in the secondary (BB) ignition circuit (spark plugs, distributor cap or slider, etc.) (see chapter Engine electrical equipment).
4. Faulty fuel injection system (see chapter Power and exhaust systems).
5. Vacuum loss occurs at the throttle body, intake piping, or through the connecting hoses (see chapter Power and exhaust systems).
6. Valve clearance adjustment is disturbed, or "sticking" valves (see chapter Settings and ongoing maintenance).
During acceleration or when the load is increased, there are knocks caused by too early ignition or detonation
1. Wrong grade of fuel filled.
2. The setting of the ignition timing is violated / the ignition system is faulty (see chapter Engine electrical equipment).
3. Faulty fuel injection system (see chapter Power and exhaust systems).
4. Damaged spark plugs or BB wires (see chapter Engine electrical equipment).
5. Worn distributor components (see chapter Engine electrical equipment).
6. The EGR valve is malfunctioning (see chapter Engine management).
7. Vacuum losses occur (see chapters Engine and Power and exhaust systems).
8. There is excessive carbon formation in the engine (see chapter Engine).
The oil pressure warning light stays on while the engine is running
1. The oil level has dropped, or the wrong grade of oil has been filled (see chapter Settings and ongoing maintenance).
2. There was a short circuit in the braid of the electrical wiring (see chapter Onboard electrical equipment).
3. Faulty oil pressure switch (see chapter Engine).
4. Worn motor bearings and/or oil pump (see chapter Engine).
5. Excessively high engine operating temperature (see chapter Cooling, heating systems).
6. The patency of the mesh filter of the oil intake is broken (see chapter Engine).
The engine continues to run after the ignition is turned off
1. Excessively high idle speed set (see chapter Engine electrical equipment).
2. Excessively high engine operating temperature (see chapter Cooling, heating systems).
3. Violated ignition timing adjustment (see chapter Engine electrical equipment).
4. There is excessive carbon formation in the engine (see chapter Engine).
5. Faulty power system (see chapter Power and exhaust systems).
Diagnostics of malfunctions of systems of electric equipment of the engine
Note. Problems associated with a failure in the starting system are discussed above in the Diagnosis of General Engine Failures subsection.
Battery not "keeps" charge
1. The alternator drive belt is worn out, or the adjustment of its tension force is broken (see chapter Settings and ongoing maintenance).
2. Decreased electrolyte level in jars (see chapter Settings and ongoing maintenance).
3. The battery terminals are oxidized, or the wire lugs are loose on them (see chapter Settings and ongoing maintenance).
4. Broken or otherwise damaged wiring circuit of the charge system, or loosened fastening of the terminals of the contact connections (see chapter Engine electrical equipment).
5. There is an internal defect in the battery (see chapter Engine electrical equipment).
6. The generator does not produce the required charge current (see chapter Engine electrical equipment).
7. Faulty generator voltage regulator (see chapter Engine electrical equipment).
8. The battery is discharging due to a short circuit in the circuit (see chapters Engine electrical equipment and Onboard electrical equipment).
Ignition/charge warning lamp stays on while engine is running
1. There is an internal defect in the generator or voltage regulator (see chapter Engine electrical equipment).
2. The alternator drive belt is worn or broken, or the adjustment of its tension force is broken (see chapter Settings and ongoing maintenance).
3. Worn, jammed or dirty alternator brushes (see chapter Engine electrical equipment).
4. Loose or broken alternator brush springs (see chapter Engine electrical equipment).
5. The charge circuit wiring is broken, or the terminal connections are loose (see chapter Engine electrical equipment).
Ignition/Charge Warning Lamp Does Not Illuminate When Engine Is Started
1. Burnt out filament (see chapter Onboard electrical equipment).
2. The printed circuit board of the instrument cluster is faulty, or the lamp holder (see chapter Onboard electrical equipment).
3. Faulty generator (see chapter Engine electrical equipment).
Diagnostics of malfunctions of systems of food and release of the fulfilled gas
Excessive fuel consumption
1. The air cleaner element is dirty or otherwise obstructed (see chapter Settings and ongoing maintenance).
2. Violated setting of the ignition timing (see chapter Engine electrical equipment).
3. Serviceability of functioning of systems of decrease in toxicity is broken (see chapter Engine management).
4. Faulty fuel injection system (see chapter Power and exhaust systems).
5. Insufficient tire inflation pressure, or wrong wheel size fitted (see chapter Settings and ongoing maintenance).
6. "tacked on" brakes (see chapters Settings and ongoing maintenance and Brake system).
There are fuel leaks or a distinct smell of gasoline
1. Damaged mechanically or as a result of corrosion of the fuel tank, fuel lines or their fitting connections (see chapter Power and exhaust systems).
2. The fuel tank is full.
3. Blocked charcoal adsorber filter (see chapters Settings and ongoing maintenance and Engine management).
4. Damaged or excessively worn internal components of injection injectors (see chapter Power and exhaust systems).
Excessively noisy or smoking exhaust system
1. There are exhaust gas leaks through the joints of the exhaust manifold or sections of the exhaust system (see chapters Settings and ongoing maintenance and Power and exhaust systems).
2. Mufflers or pipes of the exhaust system are damaged mechanically or as a result of corrosion (see chapters Settings and ongoing maintenance and Power and exhaust systems).
3. As a result of damage to the suspension mounts, the exhaust system contacts body or suspension components while driving (see chapters Settings and ongoing maintenance and Power and exhaust systems).
Diagnosis of malfunctions of the cooling system
There is overheating
1. The coolant level in the system has dropped (see chapter Settings and ongoing maintenance).
2. The patency of the radiator is broken or its grille is blocked (see chapter Cooling, heating systems).
3. Faulty thermostat (see chapter Cooling, heating systems).
4. The cooling system path is blocked by an air lock (see chapter Settings and ongoing maintenance).
5. The tightness of the radiator cap is broken (see chapter Cooling, heating systems).
6. There is a violation in the cooling fan circuit (see chapter Cooling, heating systems).
7. There is mechanical damage to the impeller of the cooling fan (see chapter Cooling, heating systems).
8. Inaccurate temperature sensor readings (see chapter Cooling, heating systems).
9. Violated adjustment of the ignition timing (see chapter Engine electrical equipment).
There is hypothermia
1. Faulty thermostat (see chapter Cooling, heating systems).
2. Inaccurate temperature sensor readings (see chapter Cooling, heating systems).
3. There is a violation in the cooling fan circuit (see chapter Cooling, heating systems).
There are external coolant leaks
1. Mechanically damaged or destroyed as a result of aging of the material, the hoses or hose clamps of the cooling path (see chapters Settings and ongoing maintenance and Cooling, heating systems).
2. Faulty water pump (see chapter Cooling, heating systems).
3. There are coolant leaks from the radiator or expansion tank (see chapter Cooling, heating systems).
4. Damaged drain or squeeze plugs of the water jacket of the engine block (see chapter Engine).
5. Faulty radiator cap (see chapter Cooling, heating systems).
6. Coolant flashed due to overheating (see chapter Cooling, heating systems).
There are internal coolant leaks
1. Broken cylinder head gasket (see chapter Engine).
2. Cracked cylinder head or block (see chapter Engine).
There is a loss of coolant
1. Too much coolant in the system (see chapter Settings and ongoing maintenance).
2. Coolant boils away due to overheating (see chapter Cooling, heating systems).
3. There are external or internal coolant leaks (see chapter Cooling, heating systems).
4. Faulty radiator cap (see chapter Cooling, heating systems).
Coolant circulation interrupted
1. Faulty water pump (see chapter Cooling, heating systems).
2. The patency of the cooling tract is broken (see chapters Settings and ongoing maintenance and Cooling, heating systems).
3. Stuck thermostat (see chapter Cooling, heating systems).
Clutch Troubleshooting
Clutch pedal sinks to the floor with little or no resistance
1. Dropped the level of hydraulic fluid in the tank (see chapter Settings and ongoing maintenance).
2. Defective clutch master/slave cylinder or hydraulic lines (see chapter Clutch and drive shafts).
3. Broken release bearing or clutch release fork (see chapter Clutch and drive shafts).
4. Broken clutch pressure plate diaphragm spring (see chapter Clutch and drive shafts).
Clutch does not disengage (unable to select gear)
1. Faulty manual transmission (see chapter Gear box).
2. Faulty clutch disc (see chapter Clutch and drive shafts).
3. Incorrectly assembled release lever with release bearing (see chapter Clutch and drive shafts).
4. Faulty clutch pressure plate (see chapter Clutch and drive shafts).
5. Loose bolts securing the clutch basket assembly to the flywheel (see chapter Clutch and drive shafts).
Clutch slips (engine speed increases without increasing vehicle speed)
1. Worn clutch disc (see chapter Clutch and drive shafts).
2. The friction linings of the driven disc are contaminated with oil seeping through the rear crankshaft oil seal (see chapter Clutch and drive shafts).
3. The new driven disk did not run in (for the final running-in of a new disc, it is necessary to make at least 30 ÷ 40 starts).
4. There is deformation of the clutch/flywheel assembly (see chapter Clutch and drive shafts).
5. Weak diaphragm spring (see chapter Clutch and drive shafts).
6. Overheated clutch disc (park the car and let the disc cool down).
Vibration occurs when the clutch is engaged
1. Contaminated with oil, burnt out, or polished to a shine friction linings of the driven disk (see chapter Clutch and drive shafts).
2. Powertrain suspension mounts worn or loose (see chapters Engine and Gear box).
3. The splines of the input shaft of the gearbox or the hub of the driven disk are worn out (see chapter Clutch and drive shafts).
4. There is deformation of the clutch/flywheel assembly (see chapter Clutch and drive shafts).
When depressing or releasing the clutch pedal, there are extraneous noises
1. Worn clutch release lever or clutch release bearing (see chapter Clutch and drive shafts).
2. Incorrectly installed shift fork stem (see chapter Clutch and drive shafts).
3. Worn or dry clutch pedal axle bushings (see chapter Clutch and drive shafts).
4. Defective clutch basket assembly (see chapter Clutch and drive shafts).
5. Broken pressure plate diaphragm spring (see chapter Clutch and drive shafts).
6. Driven disc torsion springs broken (see chapter Engine management).
7. Excessively low engine idle (see chapter Settings and ongoing maintenance).
Clutch pedal does not return to original position after releasing
1. Faulty clutch master or slave cylinder (see chapter Clutch and drive shafts).
2. Broken clutch release fork or release bearing (see chapter Clutch and drive shafts).
Clutch pedal requires too much force to depress
1. Stuck piston in master or slave cylinder (see chapter Clutch and drive shafts).
2. Defective clutch basket assembly (see chapter Clutch and drive shafts).
Diagnostics of malfunctions of a manual transmission
There are knocks that occur at low engine speeds
1. Worn CV joint (s) drive shaft (ov) (see chapter Clutch and drive shafts).
2. A socket has been developed for installing the drive shaft in the differential box (see chapter Gear box).*
There is a slight rattle that occurs when making turns
Natural sounds associated with differential operation (see chapter Gear box).*
There is a dull metallic thud that occurs during acceleration or engine braking
1. The fastening of the suspension supports of the power unit has loosened (see chapters Engine and Gear box).
2. Worn differential pinion axle.*
3. A socket has been developed for installing the drive shaft in the differential box (see chapter Gear box).*
4. Worn or damaged internal CV joint of the drive shaft (ov) (see chapter Clutch and drive shafts).
There is a metallic grinding that occurs during turns
Worn or damaged outer CV joint of the drive shaft of the inner (by turning radius) wheels (see chapter Clutch and drive shafts).
There are vibrations
1. Worn wheel bearings (see chapters Settings and ongoing maintenance and Suspension and steering).
2. Damaged drive shaft (see chapter Clutch and drive shafts).
3. Deformed tires / out of balance wheels (see chapters Settings and ongoing maintenance and Suspension and steering).
4. Worn CV joints (see chapter Clutch and drive shafts).
5. Transmission oil level dropped (see chapter Settings and ongoing maintenance).
Gearbox in neutral makes noise when engine is running
1. Worn input shaft bearings (noises appear when the clutch pedal is released and disappear when it is depressed) (see chapter Gear box).*
2. Worn clutch release bearing (noises appear when the clutch pedal is depressed and may decrease when it is released) (see chapter Clutch and drive shafts).
Noises occur in any particular gear
1. Worn, chipped or otherwise damaged transmission gear teeth (see chapter Gear box).*
2. Worn or damaged synchronizers (see chapter Gear box).*
3. Bent reverse gear fork (see chapter Gear box).*
4. Damaged fourth gear or output gear (see chapter Gear box).*
5. Worn or damaged reverse idle gear or intermediate bushing (see chapter Gear box).*
Noise occurs in all gears
1. Transmission oil level dropped (see chapter Gear box).
2. Worn or damaged bearings (see chapter Gear box).*
3. Worn or damaged gearbox input and/or output shaft (see chapter Gear box).*
Box "jumps off" from selected gear
1. The rod is worn out or its adjustment is broken (see chapter Gear box).
2. Loose bolts securing the manual transmission to the engine (see chapter Gear box).
3. Serviceability of functioning of drafts of switching is broken (see chapter Gear box).
4. Primary gear bearing holder broken or loose (see chapter Gear box).*
5. Dirt got between the clutch cover and the engine block (see chapter Gear box).
6. Synchronizer blocks worn out (see chapter Gear box).*
7. Worn shift forks (see chapter Gear box).*
Difficulty shifting gears
1. Faulty clutch (see chapter Clutch and drive shafts).
2. Worn or damaged shift drive components (see chapter Gear box).
3. Worn synchronizer blocks (see chapter Gear box).*
Transmission oil leaks
1. Damaged output differential seal (see chapter Gear box).
2. An excessive amount of gear oil is poured into the box (see chapter Settings and ongoing maintenance and Chapter Gear box).
3. Primary gear bearing holder broken or loose (see chapter Gear box).*
4. Damaged primary gear bearing retainer o-ring and/or seal lip (see chapter Gear box).*
There is a blocking of the box on any of the gears
1. Locking pin or intermediate detent pin fell out (see chapter Gear box).*
*While troubleshooting these problems is beyond the skill of the average amateur mechanic, this information will come in handy when dealing with a professional.
Troubleshooting AT
Note. In view of the complexity of the AT design, it will be difficult for an average amateur mechanic to accurately diagnose its failures and restore repairs. In case of problems other than those listed below, the car owner should seek help from car service specialists. You should also not rush to dismantle a faulty transmission, as many of its checks are made in situ (at the regular place).
ATF leaks
1. ATF is usually dark reddish in color. Traces of its leaks should not be confused with those from engine oil - the latter can be carried to the transmission crankcase by an oncoming air stream.
2. To identify the source of the leak, first of all, clean the transmission case and its surrounding surfaces from dirt and grease. Use a quality degreaser or steam clean the unit. Take the car for a short trip at low speed (so that traces of the leak are not carried far from its source). Jack up the car and place it on jack stands. Inspect the transmission case, visually identifying sources of ATF leakage. Most often these are:
- a) Transmission oil pan (see chapters Settings and ongoing maintenance and Gear box);
- b) Probe guide tube (see chapters Settings and ongoing maintenance and Gear box);
- c) Transmission oil path lines (see chapter Gear box);
- d) Speed sensor (see chapter Gear box).
ATF is brown or smells like burning
The level of ATF in the transmission has dropped, or the liquid has burnt and needs to be replaced (see chapter Settings and ongoing maintenance).
There are problems with gear selection
1. Chapter Gear box describes the procedure for checking and adjusting the AT gear selector drive. The following are the most common problems that can be associated with drive misalignment:
- a) The engine is started in a position other than "R" or "N";
- b) The transmission position displayed on the indicator panel differs from the one actually selected;
- c) The vehicle is driven with the transmission in position "R" or "N".
2. Description of the procedure for adjusting the drive mechanism of the selector is given in Chapter Gear box 7.
There is no automatic downshift of the transmission (kick-down mode) when fully depressing the gas pedal
Broken throttle cable adjustment (see chapter Gear box).
The engine does not start, or starts in a transmission position other than "R or "N"
The start enable switch is faulty, or its adjustment is violated (see chapter Gear box).
Transmission "jumps off" from the selected position, switches with difficulty or with noise, or does not provide forward or backward movement of the car
There are many possible causes of these failures, but only one of them falls within the purview of the average amateur mechanic - a violation of the ATF level. Check, if necessary, adjust the level / replace the fluid and filter, in parallel check the condition of the ATF (see chapter Settings and ongoing maintenance). In all other cases, the car should be driven away for diagnostics and reconditioning / replacement of the transmission to a service station.
Diagnosis of malfunctions of drive shafts
There is a rattle and knock that occurs during turns (at low speed and the steering wheel turned all the way)
1. Worn or damaged outer CV joint of the drive shaft located on the inside of the turning radius (see chapter Clutch and drive shafts).
2. There was a loss of CV joint lubrication, most likely due to damage to the protective cover (see chapter Clutch and drive shafts).
Vibrations occur during engine acceleration/braking
1. Excessively large convergence of the front wheels (see chapter Suspension and steering).
2. The mounting height of the suspension springs is violated (see chapter Suspension and steering).
3. Worn inner or outer CV joints (see chapter Clutch and drive shafts).
4. Stuck inner CV joint (see chapter Clutch and drive shafts).
5. Bent or otherwise deformed drive shaft (see chapter Clutch and drive shafts).
There are vibrations that occur when driving at high speeds on the motorway
1. Out of balance wheels (see chapters Settings and ongoing maintenance and Suspension and steering).
2. Deformed front wheels (see chapters Settings and ongoing maintenance and Suspension and steering).
3. Worn CV joints of drive shafts (see chapter Clutch and drive shafts).
Diagnostics of malfunctions of the brake system
Note. Before concluding that the brake system has failed, check the condition and inflation pressure of the tires, the vehicle's load evenness, and the front wheel alignment.
When braking, the directional stability of the car is violated
1. Tires not properly inflated (see chapter Settings and ongoing maintenance).
2. The adjustment of the angles of installation of the front wheels is broken.
3. One axle car (front or back) Fitted with wheels of different sizes.
4. Violated the patency of the brake lines (see chapter Brake system).
5. One or more brake mechanisms are faulty (see chapter Brake system).
6. Loose fasteners of suspension components (see chapter Suspension and steering).
7. Loose caliper mounting bolts or brake shield (see chapter Brake system).
8. Worn, damaged or oily brake pads / shoes from one of the sides of the car (see chapters Settings and ongoing maintenance and Brake system).
9. The piston of the caliper / wheel cylinder of one of the brake mechanisms is jammed, or its movement is difficult (see chapters Settings and ongoing maintenance and Brake system).
10. Brake pads / shoes with friction linings of various types are installed on different sides of the car (see chapters Settings and ongoing maintenance and Brake system).
11. Worn or damaged steering or suspension components (see chapters Settings and ongoing maintenance and Suspension and steering).
Extraneous noises occur during braking (grinding or high-frequency squealing)
1. Friction linings of brake pads are worn - pad wear sensors make a sound (see chapters Settings and ongoing maintenance and Brake system).
2. Damaged brake disc / drum - usually after a long parking of the car (see chapters Settings and ongoing maintenance and Brake system).
3. A foreign object has fallen between the disc and the brake shield (e.g. stone) (see chapters Settings and ongoing maintenance and Brake system).
During braking, the foot brake pedal vibrates
1. Excessive brake disc lateral runout (see chapter Brake system).
2. Unevenly worn brake pads (see chapter Brake system).
3. Faulty brake disc (see chapter Brake system).
Excessive brake pedal travel
1. There is a local violation in the braking system (see chapter Brake system).
2. The level of hydraulic fluid in the GTZ tank has dropped (see chapters Settings and ongoing maintenance and Brake system).
3. Air has entered the hydraulic system (see chapters Settings and ongoing maintenance and Brake system).
4. Faulty GTZ (see chapter Brake system).
5. Faulty vacuum brake booster (see chapter Brake system).
There is a softness of the brake pedal when it is squeezed out
1. Air has entered the hydraulic system (see chapters Settings and ongoing maintenance and Brake system).
2. Damaged due to aging of the material flexible brake hoses (see chapters Settings and ongoing maintenance and Brake system).
3. Loosen the GTZ mounting bolts (see chapter Brake system).
4. Faulty GTZ (see chapter Brake system).
Applying too much force to the brake pedal is required to stop the vehicle
1. Faulty vacuum brake booster (see chapter Brake system).
2. There is a local violation in the braking system (see chapter Brake system).
3. Excessively worn brake pads / shoes (see chapter Brake system).
4. Stuck piston (And) caliper/wheel cylinder (see chapter Brake system).
5. Friction linings of brake pads/boots contaminated with oil or grease (see chapters Settings and ongoing maintenance and Brake system).
6. Recently installed and did not have time to run in new brake pads / shoes.
During braking, vibration is transmitted to the brake pedal or steering wheel
1. Excessive brake disc runout/brake drum deformation (see chapters Settings and ongoing maintenance and Brake system).
2. Friction linings of brake pads/boots are worn out (see chapters Settings and ongoing maintenance and Brake system).
3. Loose caliper/brake shield mounting bolts (see chapter Brake system).
4. Worn suspension or steering components or bearings (see chapters Settings and ongoing maintenance and Suspension and steering).
There is a pulsation of the foot brake pedal when it is squeezed out during hard braking
A consequence of the correct functioning of the ABS (see chapter Brake system).
Brakes "grabs", or the uniformity of the gripping force of the brake mechanisms is disturbed
1. The adjustment of the sensor-switch of stoplights is broken (see chapter Brake system).
2. Faulty GTZ (see chapter Brake system).
3. Violated the patency of the brake lines (see chapter Brake system).
4. The adjustment of the parking brake is broken (see chapter Brake system).
5. Stuck piston (And) brake caliper/wheel cylinder (see chapter Brake system).
Braking is uneven
1. Defective control valve (see chapter Brake system).
2. Faulty vacuum booster (see chapter Brake system).
3. Stuck foot brake pedal (see chapter Brake system).
Rear wheels lock up under normal braking
1. The friction linings of the brake shoes are dirty (see chapters Settings and ongoing maintenance and Brake system).
2. There is a deformation of the discs / drums of the rear brake mechanisms (see chapters Settings and ongoing maintenance and Brake system).
Foot brake pedal sinks to the floor with no resistance
1. The fluid level in the GTZ reservoir has dropped, or there are leaks through the pistons of the calipers / wheel cylinders (see chapter Brake system).
2. Damaged brake lines or loose fittings (see chapter Brake system).
The parking brake does not hold the vehicle properly
The adjustment of the parking brake drive is broken (see chapter Brake system).
Suspension and steering fault diagnosis
Note. Before testing suspension and steering components, verify that the problem is not caused by improper tire inflation, mismatched tire sizes, wheel imbalance, or "tacking" brakes.
Violated directional stability of the car
1. Wheels of different sizes are installed on one axle, or their tires are inflated with different pressures (see chapter Suspension and steering).
2. broken or "sank" coil springs (see chapter Suspension and steering).
3. The adjustment of the angles of installation of the front wheels is broken (see chapter Suspension and steering).
4. "tacked on" front wheel brakes (see chapter Brake system).
5. There is a tire defect (see chapter Settings and ongoing maintenance).
6. Worn suspension or steering components (see chapters Settings and ongoing maintenance and Suspension and steering).
7. Suspension or steering components damaged in an accident (see chapter Settings and ongoing maintenance).
There is wheel play and increased vehicle vibration
1. Front wheels out of balance (vibration is transmitted most noticeably through the steering wheel) (see chapter Settings and ongoing maintenance).
2. The balance of the rear wheels is broken (vibration is transmitted most noticeably through the body of the car) (see chapter Settings and ongoing maintenance).
3. Damaged or deformed rims (see chapters Settings and ongoing maintenance and Suspension and steering).
4. Damaged tires (see chapter Settings and ongoing maintenance).
5. Worn steering or suspension components, or their ball joints and / or rubber-metal bushings (see chapters Settings and ongoing maintenance and Suspension and steering).
6. Loose wheel bolts (A) (see chapter Settings and ongoing maintenance).
7. Worn hub assemblies or front wheel bearings (see chapter Suspension and steering).
During cornering and braking, "galloping" and/or vehicle rocking
1. The stabilizer bar is loose (see chapter Suspension and steering).
2. Defective shock absorbers (see chapter Suspension and steering).
3. broken or "sank" coil springs (see chapter Suspension and steering).
4. Worn steering or suspension components, or their ball joints and / or rubber-metal bushings (see chapters Settings and ongoing maintenance and Suspension and steering).
5. The car is overloaded.
There is yaw or general vehicle yaw
1. Wheels of different sizes are installed on one axle, or their tires are inflated with different pressures (see chapter Suspension and steering).
2. Out of balance wheels (see chapters Settings and ongoing maintenance and Suspension and steering).
3. Loose wheel bolts (A) (see chapter Settings and ongoing maintenance).
4. There is a lack of lubrication of CV joints and tie rod ends (see chapters Settings and ongoing maintenance and Suspension and steering).
5. Worn rack assemblies (see chapter Suspension and steering).
6. Loose stabilizer bar (see chapter Suspension and steering).
7. Broken or "sank" coil springs (see chapter Suspension and steering).
8. Violated adjustment of the angles of installation of the front wheels (see chapter Suspension and steering).
9. Worn steering or suspension components, or their ball joints and / or rubber-metal bushings (see chapters Settings and ongoing maintenance and Suspension and steering).
Steering wheel turns too hard
1. The fluid level of the power steering system has dropped (see chapter Settings and ongoing maintenance).
2. Violated patency of the tract of the hydraulic power steering system (see chapter Suspension and steering).
3. Faulty steering pump (see chapter Suspension and steering).
4. There is a lack of lubrication of CV joints and tie rod ends (see chapters Settings and ongoing maintenance and Suspension and steering).
5. Tires too under-inflated (see chapters Settings and ongoing maintenance and Suspension and steering).
6. Stuck tie rod end or ball joint (see chapters Settings and ongoing maintenance and Suspension and steering).
7. Violated adjustment of the angles of installation of the front wheels (see chapter Suspension and steering).
8. Bent or damaged steering rack or column (see chapter Suspension and steering).
Excessive steering wheel play
1. Worn universal joint (s) steering column intermediate shaft (see chapter Suspension and steering).
2. Worn tie rod ends (see chapters Settings and ongoing maintenance and Suspension and steering).
3. Worn rack and pinion (see chapter Suspension and steering).
4. Worn steering or suspension components, or their ball joints and / or rubber-metal bushings (see chapters Settings and ongoing maintenance and Suspension and steering).
5. Worn hubs or front wheel bearings (see chapter Suspension and steering).
Serviceability of return of a steering wheel in a straight line position is broken
1. There has been a loss of lubrication of ball joints or tie rod ends (see chapters Settings and ongoing maintenance and Suspension and steering).
2. Stuck ball joints (see chapter Suspension and steering).
3. Steering column jammed (see chapter Suspension and steering).
4. The level of lubrication in the crankcase of the steering mechanism has fallen (see chapter Suspension and steering).
5. The adjustment of the angles of installation of the front wheels is broken (see chapter Suspension and steering).
There are extraneous noises coming from the front of the car
1. There has been a loss of lubrication of ball joints or tie rod ends (see chapters Settings and ongoing maintenance and Suspension and steering).
2. Damaged shock absorber mounts (see chapter Suspension and steering).
3. Worn suspension control arm bushings or tie rod ends (see chapter Suspension and steering).
4. The stabilizer bar is loose (see chapter Suspension and steering).
5. Loose wheel nuts (see chapter Suspension and steering).
6. Loose suspension component bolts (see chapter Suspension and steering).
Decreased vehicle control during braking
1. Worn front wheel bearings (see chapter Suspension and steering).
2. broken or "sank" suspension helical springs (see chapter Suspension and steering).
3. Warped brake discs/drums (see chapter Brake system).
The car sank excessively
Overload
There is a grinding or other extraneous noise emitted by the steering mechanism
1. Loose rack and pinion assembly fasteners (see chapter Suspension and steering).
2. There is internal damage to the steering gear (see chapter Suspension and steering).
No hydraulic boost
1. Dropped hydraulic fluid level (see chapter Settings and ongoing maintenance).
2. The patency of the power steering system hoses is impaired (see chapter Suspension and steering).
3. Faulty steering pump (see chapter Suspension and steering).
4. Defective rack and pinion (see chapter Suspension and steering).
Excessive tire wear
Increased wear on the inside or outside of the tread
1. Under-inflated tires (wear on both ends) (see chapter Settings and ongoing maintenance).
2. The adjustment of the angles of installation of the front wheels is broken (see chapter Suspension and steering).
3. Worn steering or suspension components, or their ball joints and / or rubber-metal bushings (see chapters Settings and ongoing maintenance and Suspension and steering).
4. Speed does not decrease when cornering.
5. There is a mechanical violation of the geometry of the suspension as a result of an accident.
Scale wear (fraying) protector
Convergence setting violated (see chapter Suspension and steering).
Wear of the central part of the tread
Tires are inflated too much (see chapter Settings and ongoing maintenance).
Wear on the inner and outer edges of the tread
1. Tires under-inflated (see chapter Settings and ongoing maintenance).
2. Worn shock absorbers (see chapter Suspension and steering).
Uneven tread wear
1. Tire/wheel out of balance (see chapter Settings and ongoing maintenance).
2. Excessive wheel or tire lateral runout (see chapter Settings and ongoing maintenance).
3. Worn shock absorbers (see chapters Settings and ongoing maintenance and Suspension and steering).
4. Damaged tire (see chapter Settings and ongoing maintenance).