WHAT IS CAUSING HIGH IDLE ON STARTING ENGINE, RATTLING AND PINGING NOISE
1993 Lexus SC 300
March, 23, 2011 AT 9:02 PM
I have a 1993 Lexus SC300 V6, 2JZGE engine. Just R&R another engine with about 70k miles. Upon starting enigne from cold start, the engine starts right up but has a sort of rattling sound and then it goes away. After it warms up, the engine idles perfectly, and runs well although I do get a slight "pinging" noise upon hard acceleration. Can you tell me what causes the high idle and rattle and is this connected to the "pinging" noise? I just replaced my CAT converter thinking that was the problem but both of these issues persist.
The engine computer commands the engine to operate at a higer rpm during cold start and that is normal. The rpm would vary according to conditions, signals sent to ECM by the Engine Coolant Temperature sensor.
Pinging noise during acceleration could be due to the fuel used or the ignition timing is set too high.
The rattling noise could be due to the valve lifters or slack in the timing belt tension.