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| Home / Car Engines / BMW Engines / BMW N43B20 |
BMW N43B20 Troubleshooting
| Engine won't start or difficult to start |
Empty fuel tank - Add fuel.
Low-quality gasoline - Use correct gasoline grade.
Dirty fuel system - Check and clean.
Damaged spark plug wiring connection - Check the spark plug wire connection, repair or replace.
Spark plug is defective - Change spark plug.
Ignition system malfunction - Inspect ignition system and change faulty parts.
Dirty fuel filter - Install new filter.
Clogged fuel lines - Clean fuel system lines.
Dirty or defective fuel pump - Test fuel pump and replace if necessary.
Fuel injectors are defective or dirty - Test fuel injectors and change if necessary.
Poor compression - Inspect and replace wear parts.
| Irregular engine running |
Defective ignition system - Inspect ignition system and change failed components.
Dirty air filter element - Replace or service air filter.
Faulty spark plug - Replace spark plug.
Fuel pump is dirty or defective - Inspect fuel pump and change as required.
Valve clearance is wrong - Adjust to proper valve clearance.
Ignition timing is incorrect - Set the ignition timing properly.
Too low idle RPM - Correct idle adjustment.
| Engine starts and stops suddenly |
Faulty spark plug - Change spark plug as required.
Clogged or defective fuel injectors - Clean or change fuel injectors.
Ignition coil is damaged - Ignition coil should be replaced.
Damaged or weak valve springs - Change valve springs.
Stuck valves - Service the valves.
| Engine keeps overheating |
Lack of engine oil - Check and refill engine oil.
Engine overload - Load reducing is recommended.
Clogged fuel injectors - Test fuel injectors and service if necessary.
Ignition timing is incorrect - Set the ignition timing correctly.
Improper valve setting - Valves needs to be set correctly.
Faulty radiator cap or dirty radiator fins - Change cap or clean radiator.
Insufficient coolant - Add coolant and check the components of cooling system.
Thermostat is defective - Thermostat need to be replaced.
Defective water pump - Water pump need to be replaced.
| Abnormal engine noise or knocking |
Stale or low octane fuel - Change gasoline.
Engine overloaded - Load reducing is recommended.
Engine oil level is insufficient - Need to add engine oil.
Low idle speed setting is not correct - Correct idle adjustment.
Dirty or faulty fuel pump - Test fuel pump and replace if necessary.
Crankshaft or main bearings failure - Install new parts as as required.
Valve clearance is not correct - Check and adjust.
Worn cylinder bore or piston rings - Change defective parts.
| Low engine power |
Fuel injectors are faulty or clogged - Test fuel injectors and change if necessary.
Air filter element is clogged - Replace or service air filter.
Dirty or damaged fuel pump - Clean or replace fuel pump.
Ignition failure - Inspect ignition system and change failed components.
Cylinder head gasket is worn - Cylinder-head gasket replacement required.
Valves are stuck or burned - Clean or replace valves.
Damaged cylinder block components - Change defective parts.
Oil filter is dirty - Change or service oil filter.
| High fuel consumption |
Clogged air filter - Replace or clean air filter.
Clogged or damaged fuel injectors - Service or replace fuel injectors.
Defective or loose spark plug - Spark plug need to be replaced or tightened.
Ignition timing is incorrect - Set the ignition timing correctly.
Stuck, worn, or burned valves - Clean or replace valves.
Rings, sleeve, or piston are damaged - Change defective components.
Improper valve clearance - Adjust valve clearance.
Weak cylinder compression - Inspect cylinder block and change worn parts.
| Engine using too much oil |
Damaged gaskets or seals - Replace defective parts.
Damaged valve stems or valve guides - Replace the valves.
Damaged or seized piston rings - Change piston rings.
Cylinder liner or piston is scuffed - Check liner and piston, change as required.
| Engine backfires |
Clogged fuel injectors - Clean or change fuel injectors.
Restricted fuel lines - Clean fuel lines.
Ignition timing is improper - Ignition timing needs to be adjusted correctly.
Valve setting is wrong - Set the valves correctly.
Plugged air filter - Change or service air filter.
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