Idle rpms too high - weird solution

[benIV]

So I’m not sure if it’s part of the tune, or some kind of problem, but I’m having varying idle engine speeds usually at start up or when coming to a stop.

For instance, sometimes (in the summer too) when I start the car in the morning, the idle speeds stay at around 1400-1500. It doesn’t slowly speed up or change, the engine cranks and its at that rpm and stays there.

Sometimes when I’m driving and I shift into neutral to park or whatever, the engine doesn’t fall all the way to 1000 like normal. It can stay at 1400/1500 or sometimes it sits at 1200.

The speeds are always constant and level. Sometimes I’ll notice if I’m sitting at a light, the engine might be idling at around 1000 and all of the sudden it immediately jumps to 1200 or 1400 and stays there.

The weird solution is this:

Many times I can tap the accelerator, and the engine speeds drop immediately to 1000 rpms..


I worry this is some kind of sign of a big problem about to happen.

Is it something with the tune? Is it because there’s a problem with the gp harness? Is it because the valve guides are not well sealed?

Any help please I’m very confused.

 

[Seatman]

Sounds like a possible bad cts, just had a similar issue with my latest mk4. When the idle is high you can hook up vagcom and see what sort of temp the ecu is seeing. The gauge can work fine but still have a bad reading to the ecu or vice versa.

 

[benIV]

Thanks! That is one option that I will try.