Originally Posted by billm
Hello, I have a 2000 GLE with 83000 miles. IACV was replaced at dealer about 6 months ago (79000) miles. Symptoms then were an erratic idle that was unsteady. Dealer advised that the valve was sticking, there was no coolant leaking that would cause a short and fry the ECU. Car has been running great until about 2 weeks ago.
Current symptoms are that the car will intermittently idle at 1000 - 1100 RPM when I come to a stop in traffic or at a red light. The idle is always steady, just not at 700 RPM where it should be.
When I come to a stop and idle is at 1000 - 1100 RPM and I put into Neutral, RPMs will surge to 1500 - 1700. When I come to a stop and idle is at 700 RPM (where it should be) and I put into Neutral, it stays at 700 RPM.
Is this a bad IACV, or is something else causing this. Could this be the MAF sensor??
Did you scan for codes or pending codes? If no codes then I'd suspect the MAF over the IACV, maybe trying cleaning the MAF. You could if you want measure resistance of the 4 IACV coils, s/b 22 ohms. Might also check TPS adjustment, almost seems like the linkage might be sticking so it doesn't return to the stopper at idle. Does having a/c on affect the problem?