I've had an on going issue that doesn't really cause concern, but I'd like to get it fixed if possible.

When I'm in drive and the car is warm, I have a pretty low idle and it's causes some rumbling from the engine, like it's just starting to stall. It doesn't stall and it has never died, but I know it's low. Typically 500rpm or maybe a bit lower.

If I put the transmission into neutral, the rpm goes up to 750ish and everything is smooth and quiet.

I have cleaned the MAF and throttle body recently. What would typically be next in the list of things to check?

 

Pretty sure that is normal for this car. I've seen several things on this and consensus seems to be around 500RPM in gear is normal. My 03 does the exact same thing as yours, and I have cleaned everything and also checked to make sure there were no vacuum leaks. I get some vibration when at lower idle as well but I think it's due to the engine mounts. The only thing I haven't done yet is make sure the TPS is adjusted correctly.

 

Cleaning MAF does not necessarily guarantee it ll work within specs. When you cleaned your throttle body, have you noticed an unusually high amount of dirt On the plate or idle port? Are your PCV and VSV EVAP clean and properly sealed?

 

VSV was cleaned, have not checked the PSV valve, will put that on the list.

My throttle body wasnt too bad, don't know if it had ever been cleaned before. Where is the idle port located on it?