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.
Wednesday, May 18th, 2011 AT 1:59 PM