________________________________________________________________________________________

Home / Car Engines / BMW Engines / BMW M20B23

BMW M20B23 Troubleshooting

Engine starts up hard or won't start

Gas tank is empty - Fill gasoline up.
Wrong grade of gasoline - Use correct gasoline grade.
Dirty fuel lines - Inspect and clean.
Spark plug wire is disconnected or loose - Inspect spark plug wiring connection, change or repair.
Spark plug is damaged - Spark plug need to be replaced.
Defective ignition - Check ignition and replace faulty components.
Plugged fuel filter - Install new filter.
Fuel lines are dirty - Fuel lines must be clean.
Clogged or damaged fuel pump - Clean or change fuel pump.
Dirty or damaged fuel injectors - Inspect fuel injectors and change as required.
Engine has low compression - Check cylinder block and replace defective parts.

Unstable engine running

Ignition system malfunction - Check ignition system and replace faulty parts.
Dirty air filter element - Replace or clean air filter.
Spark plug is damaged - Replace spark plug.
Fuel pump is defective or dirty - Test fuel pump and change if necessary.
Incorrect valve clearance - Adjustment procedure required.
Ignition timing is incorrect - Adjust ignition timing correctly.
Low idle speed setting is not correct - Correct idle settings.

Engine starts but then stops

Damaged spark plug - Spark plug need to be replaced.
Fuel injectors are faulty or clogged - Test fuel injectors and replace if necessary.
Faulty ignition coil - Replace ignition coil as necessary.
Valve springs are weak or broken - Install new valve springs.
Valves are stuck - Valves need to be cleaned.

Engine is overheated

Engine oil level is insufficient - Need to add engine oil.
Engine is under excessive load - Load reducing required.
Clogged fuel injectors - Inspect fuel injectors and service as required.
Ignition timing is wrong - Set the ignition timing properly.
Improper valve setting - Adjust valves as required.
Radiator core is clogged or radiator cap is leaking - Clean radiator or change cap.
Coolant level is low - Refill to the correct level and inspect system for leaks.
Thermostat is faulty - Install new thermostat.
Water pump failure - Water pump need to be replaced.

Engine knocks or noises

Stale fuel - Use correct fuel.
Engine is under excessive load - Reduce load.
Engine oil insufficient - Check oil level and add oil as required.
Incorrect low idle setting - Adjust the low idle speed.
Dirty or damaged fuel pump - Inspect fuel pump and change as required.
Crankshaft or main bearings wear - Install new parts as as required.
Valve clearance is improper - Adjust valve clearance.
Cylinder bore or piston rings are worn - Replace defective components.

Engine loses power

Fuel injectors are faulty or clogged - Check fuel injectors and change if required.
Air filter element is clogged - Clean or replace air filter.
Fuel pump is faulty or clogged - Inspect fuel pump and change as required.
Defective ignition - Check ignition system and replace faulty parts.
Defective cylinder head gasket - Replace the gasket as required.
Stuck or burned valves - Clean or replace valves.
Cylinder block components are faulty - Change defective components.
Plugged oil filter - Service or replace oil filter.

High fuel consumption

Dirty air filter element - Service or replace air filter.
Dirty or faulty fuel injectors - Clean or change fuel injectors.
Loose or defective spark plug - Tighten or change the spark plug.
Ignition timing is wrong - Adjust ignition timing correctly.
Valves are worn, stuck, or burned - Clean or replace valves.
Worn sleeve, rings, or piston - Replace faulty parts.
Excessive valve clearance - Adjustment procedure required.
Poor engine compression - Check cylinder block and replace damaged components.

Engine oil consumption is too high

Worn seals or gaskets - Replace worn parts to avoid leaks.
Valve guides and stems are worn - Change the valves.
Piston rings are stuck or worn - Piston rings replacement required.
Cylinder liner or piston is worn - Check liner and piston, install new components as required.

Engine backfires

Dirty fuel injectors - Test fuel injectors and service if necessary.
Restricted fuel lines - Fuel lines must be clean.
Wrong ignition timing - Adjust ignition timing correctly.
Improper valve setting - Adjust valves as required.
Clogged air filter - Clean or change air filter.

________________________________________________________________________________________

________________________________________________________________________________________

Engines Technical Specifications
BMW M20B23 BMW M40B18 BMW M43B16 BMW M50B24TU
TOYOTA 3VZ-E TOYOTA 1AZ-FE TOYOTA 1G-FE TOYOTA 1JZ-GE
NISSAN HR12DE NISSAN A12 NISSAN A15 NISSAN CA18DET
BRIGGS 28S777 BRIGGS 31H777 BRIGGS 31P977 BRIGGS 31Q777
MERCURY 150 MERCURY 175 XRI MARINER 135 MERCURY 200 EFI
KAWASAKI FH430V KAWASAKI FR600V KAWASAKI FX541V KAWASAKI FD611V
HONDA GC135 HONDA GCV160 HONDA GS190 HONDA GX340
KUBOTA D1305 KUBOTA D1503 KUBOTA V1903 KUBOTA 2003T
KOHLER CH18S KOHLER CH680 KOHLER CV460S KOHLER SV735S