idle problem

[tricky]

i'm having an issue when my car is in park and on....it's reving to hight...the rev needle keeps on going up and down....up to 1.5 revs....when l put it in netural it's fine....would a tune up help with my car reving problem....maybe changing the spark plugs

[Talibangunner925]

if its cold out its norm for it to rev at 1500 to warm it up qicker but if it is warm and keeps going up in down it could be the spark plugs like you said or dirty fuel injectors

[Dudis Dinkle]

Are you saying that the engine is surging to 1,500 or just staying there? If there is a surge, where the engine revs to 1,500, settles down but keeps repeating this, and it only happens in park but not in nuetral, you may have a problem with the tranny switch which feeds info to the computer.

[tricky]

it keeps repeating.....also my check engine light just went on today....if it is the ran switch is it expensive to replace

[Dudis Dinkle]

Yeah, they are pretty pricey. Definitely check out that light before you purchase any parts.

If you are a do it yourselfer and will be keeping the car for a while, you may want to consider this software and interface:

http://www.ross-tech.com/vag-com/index.html

It is a bit pricey as well but I picked one up last year, and it really is good stuff. If you would rather not spend that kind of money on diagnostic equipment a code scan is usually around $35-50