Any deviations from the norm on the car (noise, knocking, loss of control, etc.) need to determine the source of the malfunction and the method of elimination
- Possible cause - Method of elimination
Characteristic high-pitched metallic knock from under the engine valve cover:
- - Violation of valve clearances - Adjust the valve clearance
- - Broken (increased wear) supports (bearings of supports) of camshafts - Replace or repair timing components
- - Malfunction of hydraulic compensators - Replace
Clunking/hissing noise from under the front engine cover (front of the engine):
- - Reduced tension of the timing chain (gas distribution mechanism) - Tighten the chain
- - Worn camshaft drive sprockets - replace
- - Increased wear of the timing chain - replace
A dull short knock from the bottom of the engine when starting it (two knocks):
- - Worn thrust bearings (half rings) of the crankshaft - replace
Knock (clicks) when moving the ignition key to the "Start" position:
Clicks while the key is in the "Start" position occur due to a malfunction of the starter holding winding
In an emergency, you can use a screwdriver with an insulated handle to short-circuit the terminals of the starter holding winding.
Rattling (clacking) metallic knocking coming from fuel injectors (for diesel engines)
When this sound occurs, black smoke may appear from the exhaust pipe
- Malfunction of the injectors and/or the entire fuel system of the engine.
If scale forms on the injector nozzles, fuel may leak, which may cause a loss of power and the appearance of black smoke from the exhaust pipe.
Carry out maintenance of the fuel system
Squeaking, squealing, whistling from the front of the engine:
- - Worn or reduced tension of the accessory drive belts - Tighten the belts or replace
Steam from the engine compartment:
- - Engine overheating due to malfunctions in the cooling system - Stop and let the engine cool down. The reason may be very high ambient air temperature
Check the cooling system fuses and the fan
Loss of engine power due to overheating
The coolant temperature gauge is in the red zone:
- - Insufficient heat dissipation due to clogging of the radiator cells of the cooling system with foreign objects (road debris, leaves) - Clean the radiator using a special brush
- - Breakdown of the cooling system fan or faulty electrical wiring - Check the technical condition and replace
- - Mechanical damage to the radiator - replace
- - Coolant leakage through loose pipe connections or damage to the radiator, cylinder block or cylinder head - Detect the leak and fix the malfunction
- - Insufficient coolant level in the system - top up the liquid to required level
Smoke from the engine compartment (after engine repair):
After engine repair, engine oil often gets on the block and cylinder head, if it is not removed by wiping with a clean rag, then after turning on and as the engine warms up, smoke will start coming from under the hood, this is due to oil burning.
As a rule, it does not pose a danger, but it is still better to turn off the engine and clean the block and cylinder head with a clean rag.
Make sure that after repair the head and cylinder block are cleared of engine oil streaks, if necessary, clean using a rag and solvent
Popping sounds in the intake manifold:
- - Shifting the ignition timing to the earlier side - This malfunction can lead to serious damage to the intake system and connecting rod and piston group. Perform repairs
Difficult to engage or change gears
(for cars with a manual transmission):
- The clutch is dragging, i.e. the clutch does not fully disengage when the pedal is fully pressed.
A characteristic knock of the synchronizers is heard when shifting
Adjust the working stroke of the clutch pedal
Replace the driven clutch disc
- - Malfunction of the gear shift cable - Replace the gear shift cable
- - Loose or worn locking rings and cones of the synchronizers - Repair the malfunction or replace the parts
- - Loose synchronizer springs - Replace the synchronizer springs
- - The wrong grade of oil is poured - Fill with the required brand of oil
A dull, clicking, short-term knock coming from the gearbox when shifting
(cars with manual gearbox)
The knocking disappears when the clutch is pressed twice:
- - Increased wear of the gearbox synchronizer(s) - replace
A dull knock when shifting gears
- (manual and automatic transmissions) coming from the central tunnel.
Usually these are two or three knocks:
- - Increased wear of the universal joints of the driveshaft (typical for all-wheel drive and rear-wheel drive vehicles) - Replace
- - Imbalance of the driveshaft - Perform balancing
Metallic "crunch" and knocking when turning the car:
The car "breaks off" trajectories.
- Malfunction of the main gear differential.
Note:
This is mainly jamming of the satellites due to wear or misalignment. Make repairs
Characteristic metallic "crunch" and beating of balls when turning
- (all-wheel drive or front-wheel drive vehicles):
Dirt getting into the CV joint (constant velocity joint) due to a torn boot - Replace the CV joint
Avoid starting off and increased loads when starting with the wheels fully turned (front-wheel drive vehicles), as this can damage the CV joints.
Whistling when pressing the clutch pedal:
- - Lack of lubrication or wear of the clutch release bearing - Replace the release bearing
A dull short-term knock when pressing the clutch pedal:
- - Wear of the gearbox input shaft bearing gears (manual gearbox) - Replace
- - Violation of the adjustment of the clearance in the engagement of the main gear - Disassemble, check the technical condition and adjust
A “buzzing” sound from the side of the main gear reducer (mainly under load):
- Insufficient or no transmission oil in the main gear housing - Top up or fill in the required volume of transmission oil
If there was no transmission oil, it is necessary to identify the cause of the leak and check the technical condition of the main gear, in case of increased wear - replace with a new one
Clutch slippage as a result of which:
- - the car does not respond to an increase in engine speed, inappropriate vehicle speed.
- - lack of power when driving up a slope
A characteristic smell of friction fluid may appear in this case. material.
- - Inadequate pedal free play - Worn or damaged pressure spring
- - Clogged clutch hydraulic system - Repair the fault
- - Excessive wear on the surface of the clutch disc
- - Glazed surface of the clutch disc or oil on the surface
- - Damaged pressure plate or flywheel - Replace
Spontaneous gear disengagement:
- - Worn gear shift forks or broken detent springs in the coupling - Replace the fork or detent
- - Increased clearance of the synchronizer sleeve on the hub - Replace the hub and synchronizer sleeve
Grabbing/vibration clutch:
- - Oil on the surface of the clutch disc or burning - Check the clutch disc
- - Faulty clutch pressure plate - Replace the clutch basket
- - Damage to the diaphragm spring - Replace the clutch basket
- - Damage or wear of the damper springs of the clutch disc - Replace the clutch disc
- - Loose mount to the engine - fix the fault
A dull metallic knock at the top of the shock absorber strut (shock absorber)
- when driving over road bumps or obstacles:
The shock absorber strut support (upper shock absorber mount) is broken
Do not confuse with a suspension breakdown when driving over a road obstacle
Replace the shock absorber strut support and check the technical condition of the shock absorber strut
Overheating of the wheel rim and wheel hub:
- - Skew during installation or increased wear of the wheel hub bearing - Replace, adjust
Increased wear of the ball joint of the steering rod end:
To determine wear, replace the steering rod end:
Hang up the wheel being checked, place a support under the lower suspension arm.
Take hold of the wheel by the front and rear parts and swing it horizontally.
If a knock appears, then the ball joint is excessively worn and must be replaced
- Increased wear of the ball joint of the lower suspension arm - Replace
To determine wear, you must:
Hang up the wheel being checked, place a support under the lower suspension arm.
Grab the wheel at the top and bottom and swing it in the vertical plane.
If a knock appears, ask an assistant to press the brake pedal and repeat the wheel movements.
If the knocking does not disappear after pressing the brake pedal, then the ball joint is excessively worn and needs to be replaced.
Knocking coming from the car's suspension:
- Worn wheel hub bearings - Replace
To determine wear, you need to:
- - Hang up the wheel being checked, place a support under the lower suspension arm.
- - Grasp the wheel at the top and bottom and swing it in a vertical plane.
- - If a knock appears, ask an assistant to press the brake pedal and repeat the wheel movements.
- - If the knocking disappears after pressing the brake pedal, then the wheel hub bearing needs to be replaced
- - Worn anti-roll bar struts - replace
- - Worn anti-roll bar bushings (often manifests itself when turning the car) - replace
Vibrations in the steering wheel with increasing speed:
- - Vibrations are possible due to poor road surface
- - Beating of the steering wheels, as a result of imbalance (with a subsequent increase in speed, shocks are heard in the suspension, jerks of the car are possible)
Can lead to very serious damage to the chassis and steering of the car
Balance the wheels, if necessary, check the technical condition of the chassis as a whole. Check the steering wheel alignment angles
- The chassis and/or steering mounting elements have become loose
Self-locking nuts/bolts or castle nuts with subsequent cotter pinning are used to secure the chassis and steering elements. Be especially careful that the nuts are properly cotter pinned during installation.
- - Dirt or ice on the wheels and/or wheel arches.
- - Wheel mounting bolts/nuts have become loose.
Tighten all chassis elements to the required tightening torque
Noise during operation of the hydraulic power steering:
- Air entering the system
Make sure that air does not enter through loose connections.
Perform the air bleeding procedure from the system, for this:
Set the car in the direction of straight-ahead movement.
Open the hood and the cap of the expansion tank of the power steering pump.
Start the engine and turn the steering wheel from one extreme position to the other to remove air from the system.
The air is removed if there are no air bubbles in the pump tank when turning the steering wheel
- - Increased wear of the working surfaces of the power steering pump - replace
- - Low level of working fluid - Eliminate leaks
- - Leakage of working fluid due to a violation of the tightness of the connections and / or leakage through the seals - Replace
Swinging of the car when driving on an uneven road surface:
- - Leaks of working fluid from the shock absorber (-s), resulting in loss of damping capacity of the shock absorber - Replace
Car drifts away from straight-line movement:
- - Violation of the steering wheel installation angles - Adjust the installation angles
- - Uneven wear of the tires - See "Types of tire wear"
- - Violations in the installation of the steering wheel - Adjust
- - Sticking of the brake pads on one side of the car
You can check by hanging each wheel in turn and turning it by hand. The wheel should rotate freely, without jamming.
In this case, smoke may appear from the brake mechanism (burning of dust and friction material)
- - Violation of the geometric parameters of the suspension elements (levers, steering knuckle, rods) - Check the geometric parameters on a special stand. If necessary, replace defective parts
- - Malfunction of the passive safety systems ABS, ESP (electronic stability program), ASR (traction control system)
Read the fault codes using a special scanner.
If necessary, carry out repairs
Loss of braking efficiency
(Increased force is required when pressing the brake pedal):
- - Damage or malfunction of the brake booster - Replace
- - Excessive wear of the friction linings of the brake pads
Note:
Braking may also be accompanied by a metallic squeak. - Replace
- - Brake pads are skewed (installation fault) - Replace
- - One of the brake hydraulic circuits is leaking
The brake pedal will fall through approximately half of its travel
Find the leak and repair
- Freezing of individual brake components during winter operation
At low speed, several Press the brake pedal just once to warm up the brakes
The brake pedal has sunk, the car barely slows down:
This is a very dangerous situation, as it may result in a traffic accident.
The reason is the air in the brake system.
Note:
In an emergency while driving, if this situation occurs, you must press the brake pedal several times in turn and, if necessary, carefully use the parking brake
Before each trip, you must check the technical condition of the brake system (see above) in order to find and fix the problem early. Bleed the brake system.
- - Brake fluid leak from the brake hydraulic system - Find and fix the leak
Extraneous noises from body components:
- - Loose fasteners - Retighten to the required tightening torque
- - Insufficient clearance between body components
If possible, separate the components by loosening and tightening their fasteners to the required tightening torque.
Isolate the components using suitable materials, such as polyurethane pads, foam pads, felt tape or polyurethane tape