So i had perfected my idle rpm a month or so ago using the idle air screw, but since then i had to replace my tstat, and since then it has idled higher and i have no idea why. On warm/hot starts it sometimes idles where it should, not sure what to think about that. Ive played around with the idle air screw a bit but i havent seen any improvement having done so. What do yall think it could be?

 

Could be the TPS and or the fast idle cam among other things.

 

Do you have the OMP still? The rod that connects it passes very near the Tstat area. May be binding or hanging up in that tight area.

 

Oops, I see you have a S5. Never mind.

 

Is your throttle cable adjusted properly and not holding your intake slightly open?

 

Its actually too loose. Havent gotten around to correcting it.

 

Ok, if you know that the only thing you've touched was to get access to your Tstat housing, I'd double check your connections around it and see if you've accidentally bumped your intake neck, check one of the vacuum hoses for a leak somewhere next. Who knows, you may have encountered a leak while doing a different job, it happens and makes for an unusual diagnosis sometimes.

The only other thing I can think of idle wise that would assist with your cooling system would be your thermowax which is now absorbing the correct amount of heat instead of what it was before. May need readjustment.

 

And also check to see if the plug off of the water thermosensor came loose.