Dan Rufer

For an '87 Carrera that I recently purchased, I am getting in the habit of checking the oil at the end of every drive. However, each time I remove the oil cap, my idle drops. It only drops by a 100 or 200 RPMs. Why might the idle drop with the removal of the oil cap? Thanks.

Chris Bennet

If trhe idle stabilizer valve isn't doing it's job the idle speed will change when you remove the cap. -Chris

TYPE911

Dan
this is normal. All the 911's I have owned
have done this. No worries

Chris Bennet

It's normal - for cars that don't have an idle stabilizer (pre-Motronic) such as 911SC's.
-Chris