SOURCES OF ENGINE NOISE

 SOURCES OF ENGINE NOISE

1) MISFIRING or BACKFIRING.

POSSIBLE CAUSES.

- Fuel in tank has wrong octane/cetane number, or is wrong type of fuel.

- Ignition system faulty.

- Engine temperature too high.

- Carbon deposits in the combustion chamber start to glow and cause misfiring.

- Timing incorrect, which causes misfiring in the intake/ exhaust system.

REQUIRED ACTION

- Determine which type of fuel was last put in the tank.

- Check the ignition system

- Check the engine cooling system

- Remove the carbon deposits by using fuel additives and driving the vehicle carefully

- Check the timing

2) VALVE TRAIN FAULTY.

POSSIBLE CAUSES.

- Valve clearance too large due to faulty bucket tappets or incorrect adjustment of valve clearance.

- Valve timing incorrectly adjusted valves and pistons are touching.

- Timing belt broken or damaged.

REQUIRED ACTION

- Adjust valve clearance if possible and

renew faulty bucket tappets – check cam

condition.

- Check the valve timing and adjust if necessary.

- Check timing belt and check pistons and

valves for damage – renew any faulty parts.

3) FAULTY ENGINE COMPONENTS.

POSSIBLE CAUSES.

- Pistons.

- Piston rings.

- Cylinder head gasket.

- Big-end and/or main bearing journals.

REQUIRED ACTION.

- Disassemble the engine and check

components.

4) ANCILLARY COMPONENTS

POSSIBLE CAUSES

- Engine components or ancillary components loose or broken.

REQUIRED ACTION.

- Check that all components are secure, tighten/ adjust as required. Renew if broken.