Fast Idle when cold?

Don't know if it's related, but twice since getting my water pump replaced, even though the car is warmed up (according to the temp gauge) the idle has stayed at 1100rpm, not gone down all the way to 750. This has only happened on fairly cold days, and it's as if a fast idle device is stuck. Is there a "fast idle" valve or switch on this car? If not, what could be causing this? Eventually on both occassions the car idled as normal, but held at 1100 for much longer than usual -- as if something is starting to stick... I hope this makes sense. Any thoughts? Thanks.

[Beav]

It could be one of a few things. More than likely you need to remove and clean the throttle body and the device under it - the IAC, otherwise known as the idle air controller. Oil vapors collect in the t-body and IAC and gum them up. It's common to almost every car with electronic injection.

Another cause may be if you have disconnected the battery and the ECU is relearning its idle routine. (this may also occur after cleaning the t-body) It took mine 3-4 days to complete the relearn procedure, no driver intervention required.

How much of a pain is removing this stuff? I think my PCV valve is also clogged and in need of cleaning or replacement.

CJ

Well.. the temperature gauge is your coolant temperature, not your engine oil temperature. Perhaps your engine is warmed up completley but the coolant is.

>shrug<

- Ca$h

[nubs]

Originally posted by $VX
Well.. the temperature gauge is your coolant temperature, not your engine oil temperature. Perhaps your engine is warmed up completley but the coolant is.

>shrug<

- Ca$h

[Ron Mummert]

Originally posted by nubs

Yeah... Hey, Mike - is this comment from Ca$h the result of too much wine or too little English 101?

Ron.

[nubs]

Originally posted by Ron Mummert


Yeah... Hey, Mike - is this comment from Ca$h the result of too much wine or too little English 101?

Ron.

I don't know Ron. I read it again this morning, and it still does not make any sense.Maybe there is some hidden code in it.

Ack. Retry: Alright, the temperature guage in the SVX is hooked up to a sensor that reads how hot the engine coolant is correct? Maybe the SVX's ENGINE (not the coolant) oil temperature is not that high yet so it continues to idle kinda high. Just a thought.

- Ca$h

[nubs]

Originally posted by $VX
Maybe the SVX's ENGINE (not the coolant) oil temperature is not that high yet so it continues to idle kinda high. Just a thought.

- Ca$h

I have never seen nor heard of any car using oil temperature sensors to control any engine functions. Has anyone else?

[Beav]

A lot of German OEMs use oil temp as a means to determine engine temp when performing diagnostics (especially air cooled VWs ), but I can't remember actually seeing an on-board sensor. As far as I know all OEMs use a separate water temp sensor for the ECU and another for the gauge.

[Landshark]

Originally posted by cjoffe
How much of a pain is removing this stuff? I think my PCV valve is also clogged and in need of cleaning or replacement.

CJ

who wants to be the one to tell him about the PCV removal? i hope you're flexible. its not really THAT bad, but might be one of the hardest i've done. then again, i haven't done a million of them either.
just a quick play-by-play:
remove both plastic covers on the top of the engine.
the PCV valve is under the rear of the rectangular plastic cover (with the allen bolts) - it threads in at an angle upwards towards the front of the car.
you'll have to pull the hose off, and using a 19mm crow's foot wrench, loosen it. this is what is so hard - there is VERY LITTLE room to move in that little U-shaped notch. removing and tightening the new one takes a long time and kills your back. i was able to CAREFULLY reach my arm in from the rear of the engine compartment to get under the PCV (avoid disturbing wires and hoses) to hand loosen and tighten as much as i could.
i can't remember, but you may need to put some teflon tape on the new PCV threads.

don't use this as a How-To guide - i just wanted to give you a quick idea of what's involved. do a search - i found an excellent write-up somewhere. good luck!