Abnormal noise is a typical sign of engine failure. Rattling sound during idle or acceleration troubles many users. We list common faults for mainstream petrol engines.
1、Timing chain noise
Appear on Toyota 1ZR, 2ZR, 1AZ, 2AZ, Nissan KA24DE. Caused by worn chain or loose tensioner. Mild noise is acceptable; loud rattle needs to replace tensioner and chain.
2、Loose accessory belt
Belts for alternator, water pump become loose after long use. It makes continuous rattling when engine runs. Just adjust belt tightness or replace the belt.
3、Loose heat shield
Metal heat shield around exhaust pipe vibrates and makes noise. This is a simple problem, fix by tightening bolts or removing the shield.
4、Valve clearance too big
Typical on high-mileage Hyundai G4FC and Nissan KA24. It makes regular ticking sound. Adjust valve clearance to solve it.
Reminder
Do not drive for long time with loud internal engine noise. It will lead to more expensive repairs.
