Symptom | Possible reason |
Engine won't crank when trying to start | The battery terminals are oxidized, or the wire lugs are loose on them (see chapter Car maintenance). |
Low or defective battery (see chapter Car maintenance). | |
Poorly put into position "R" automatic transmission (see chapter automatic transmission (AT)) or - on models with a clutch switch - the clutch is not fully depressed (see chapter Clutch). | |
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 chapters Ignition system and Onboard electrical system). | |
Starter drive gear teeth stuck in flywheel ring gear (see chapter Ignition system). | |
Faulty starter relay (see chapter Ignition system). | |
Faulty starter motor (see chapter Ignition system). | |
Faulty ignition switch (see chapter Onboard electrical system). | |
Broken or worn starter drive gear teeth or flywheel crown (see chapters Engine and Engine management and emission control systems). | |
There is internal engine damage (see part Engine Component Overhaul Procedures). | |
Engine cranks but won't start | Empty fuel tank. |
Low battery (engine cranks too slowly) (see chapter Ignition system). | |
The battery terminals are oxidized, or the wire lugs are loose on them (see chapter Car maintenance). | |
There are fuel leaks through the injector (s), the fuel pump or pressure regulator is faulty, etc. (see chapter Supply system). | |
Fuel does not reach the injection/carburetor system (see chapter Supply system). | |
Moistened or damaged ignition system components (see chapter Ignition system). | |
Stuck open fuel injector (see chapter Supply system). | |
Worn or damaged spark plugs, or incorrect electrode gap setting (see chapter Car maintenance). | |
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 Ignition system). | |
The distributor mounting bolts were loosened, which led to a failure to set the ignition timing (see chapters Car maintenance and Ignition system). | |
The wiring of the ignition coil is broken or otherwise damaged, or the fastening of the terminals of the contact connections is loose (see chapters Ignition system). | |
Faulty ignition coil (see chapter Ignition system). | |
Difficulty starting a cold engine | Low battery (see chapter Car maintenance). |
The functioning of the power system is disrupted (see chapter Supply system). | |
There is a leak through the injector (s), or the functioning of the automatic start is disrupted (see chapter Supply system). | |
Coal tracks formed on the ignition distributor slider (see chapter Ignition system). | |
Difficulty starting a hot engine | The air cleaner filter element is dirty, or its patency is otherwise impaired (see chapter Car maintenance). |
Fuel does not reach the injection/carburetor system (see chapter Supply system). | |
Battery terminals are oxidized - special attention should be paid to the condition of the ground terminal (negative) (see chapter Car maintenance). | |
Entering the starter into gear is difficult, or accompanied by extraneous noise | Broken or worn starter drive gear teeth or flywheel crown (see chapter Ignition system). |
Loose or loose starter mounting bolts (see chapter Ignition system). | |
Engine starts but immediately stalls | Loose fastening of the terminals of the contact connections on the distributor, ignition coil or generator (see chapter Ignition system). |
The serviceability of fuel supply to the injectors of the injection system / carburetor is broken (see chapters BMW 5-series cars and Supply system). | |
Faulty fuel injection speed sensors (see chapter Ignition system). | |
The relay of an electric circuit of system of injection is faulty (see chapter Ignition system). | |
Oil leaks under the engine while the car is parked | There are leaks at the gasket and/or drain plug of the oil pan (see chapter Engine). |
There is a leak at the oil pressure sensor (see chapter Engine). | |
There are leaks from the cylinder head cover gaskets (see chapter Engine). | |
There are leaks through the engine shaft seals (see chapter Engine). | |
Idle speed stability is broken | There are vacuum losses (see chapter Supply system). |
Air cleaner element blocked (see chapter Car maintenance). | |
The fuel pump is not supplying the proper amount of fuel to the injection system/carburetor (see chapter Supply system). | |
Cylinder head gasket leaking (see chapter Engine). | |
Worn timing belt / chain or its gears / sprockets (see chapter Engine). | |
Camshaft lobes worn out (see chapter Engine). | |
Defective carbon adsorber (if provided) (see chapter Engine management and emission control systems). | |
Ignition misfire occurs at idle | Worn or damaged spark plugs, or incorrect electrode gap setting (see chapter Car maintenance). |
Faulty spark plug wires (see chapter Car maintenance). | |
There are vacuum losses (see chapter Car maintenance). | |
The setting of the ignition timing is violated (see chapter Ignition system). | |
Compression pressure dropped or unevenly distributed between the cylinders (see chapter Engine). | |
Defective carbon adsorber (if provided) (see chapter Engine management and emission control systems). | |
Misfire occurs while driving in gear | The patency of the fuel filter is broken, or the power system is contaminated (see chapter Car maintenance). |
The injectors do not provide adequate fuel injection, or the patency of the carburetor fuel jets is partially impaired (see chapter Supply system). | |
Worn or damaged spark plugs, or incorrect electrode gap setting - petrol models (see chapter Car maintenance). | |
The setting of the ignition timing is violated (see chapter Ignition system). | |
Cracked distributor cap, disconnected BB wires, or damaged other components of the distributor (see chapter Car maintenance). | |
Faulty spark plug wires (see chapter Car maintenance). | |
Components of systems of decrease in toxicity of the fulfilled gases are faulty (see chapter Engine management and emission control systems). | |
Compression pressure dropped or unevenly distributed between the cylinders (see chapter Engine). | |
Ignition system malfunction (see chapter Ignition system). | |
There is a loss of vacuum in the injection system, in the intake pipe or through the connecting hoses (see chapter Supply system). | |
Misfire occurs during engine acceleration | Faulty spark plugs (see chapter Car maintenance). |
The functioning of the injection / carburetor system is disturbed (see Chapter Supply system). | |
Fuel filter blocked (see chapters BMW 5-series cars and Supply system). | |
The setting of the ignition timing is violated (see chapter Ignition system). | |
There are air leaks in the intake manifold (see chapter Supply system). | |
Engine speed spontaneously increases when the gas pedal is held still | There are intake air leaks (see chapter Supply system). |
Faulty fuel pump (see chapter Supply system). | |
Loose fastening of the terminal connections of the wiring harness of the fuel injector (see chapters Supply system and Engine management and emission control systems). | |
Faulty electronic control unit (ECU) (see chapter Ignition system). | |
Decreased engine power | The setting of the ignition timing is violated (see chapter Ignition system). |
Excessive play of the distributor shaft (see chapter Ignition system). | |
Worn slider or distributor cap, or BB wires (see chapters BMW 5-series cars and Ignition system). | |
Faulty spark plugs or incorrect electrode gap adjustment (see chapter Car maintenance). | |
The functioning of the injection / carburetor system is disturbed (see chapter Supply system). | |
Faulty ignition coil (see chapter Ignition system). | |
Sticky brakes (see chapter Car maintenance). | |
Low automatic transmission fluid level (see chapter Car maintenance). | |
Clutch slips (see chapter Clutch). | |
Blocked fuel filter and/or contaminated fuel system (see chapter Car maintenance). | |
Functioning of systems of decrease in toxicity of the fulfilled gases is broken (see chapter Engine management and emission control systems). | |
Compression pressure dropped or unevenly distributed between the cylinders (see chapter Engine). | |
The engine spontaneously stalls | The idle speed setting is violated (see chapter Car maintenance). |
The patency of the fuel filter is broken, or moisture or other contaminants get into the power system (see chapter Car maintenance). | |
Wet or damaged distributor components (see chapter Ignition system). | |
Components of systems of decrease in toxicity of the fulfilled gases are faulty (see chapter Engine management and emission control systems). | |
Faulty spark plugs or incorrect electrode gap adjustment (see chapter Car maintenance). | |
Faulty spark plug wires (see chapter Car maintenance). | |
There is a loss of vacuum in the injection system, in the intake manifold or through the connecting hoses - petrol models (see chapter Supply system). | |
happening "shots" in the exhaust system | Functioning of systems of decrease in toxicity of the fulfilled gases is broken (see chapter Engine management and emission control systems). |
The setting of the ignition timing is violated (see chapter Ignition system). | |
Faulty secondary circuit of the ignition system (defects in the insulators of candles, explosive wires, cover and / or distributor runner) (see chapter Ignition system). | |
The functioning of the fuel injection / carburetor system is disturbed (see chapter Supply system). | |
There is a loss of vacuum in the injection system, in the intake manifold or through the connecting hoses - petrol models (see chapter Supply system). | |
Broken valve clearances (see chapter Car maintenance), possibly damaged or stuck valve (s) (see chapter Engine). | |
Detonation sounds occur during engine acceleration or when driving uphill | The vehicle was filled with the wrong grade of fuel. |
The setting of the ignition timing is violated (see chapter Ignition system). | |
Fuel injection system/carburetor needs adjustment (see chapter Supply system). | |
Damaged spark plugs or BB wires, wrong type of plugs may have been installed (see chapter Car maintenance). | |
Worn or damaged distributor components (see chapter Ignition system). | |
Faulty exhaust emission control system (see chapter Engine management and emission control systems). | |
There are vacuum losses (see chapter Supply system). | |
Oil pressure warning light stays on after successful engine start Stop the engine immediately and find out the cause of the failure. Operation of the engine with reduced oil pressure is fraught with serious engine damage! | The oil level has dropped, or the wrong type of oil has been filled (see chapter Car maintenance). |
Excessively low idle speed (see chapter Car maintenance). | |
There is a short circuit in the wiring (see chapter Onboard electrical system). | |
Faulty oil pressure switch (see chapter Engine). | |
Worn engine bearings and/or oil pump (see chapter Engine). | |
The engine continues to run after the ignition is turned off | Excessively high idle speed (see chapter Car maintenance). |
Engine operating temperature is too high (see chapter Cooling system). | |
The octane rating of the fuel does not match the engine specifications. | |
Faulty spark plugs or incorrect electrode gap adjustment (see chapter Car maintenance). |