Idle Fluctuates

[justinvolvo70]

Hi,
Im working on a 2001 V70 Turbo, Automatic.
The idle is fluctuating from normall to really low and then back up to normal agian. It does this almost rythmically up and down up and down....etc. Off idle is fine. Its just that when you stop, the idle drops down to nearly a stall and then bounces back up to normall for a second and then drops back down. Are there any common problems that cause this situation? Thanks for any info

[otis44]

Sounds like the etm is on the way south. Search etm or throttle body on this forum and you will find alot of reading. Cleaning it might help. Many people purchase what I assume is a reman unit from Xemodex that solves this problem.

[justinvolvo70]

Ok thanks i'll look into that.

[jack-of-all]

This happen to me(2002 XC70) right before my mass air flow sensor failed. Code showed up a few days later. Replaced sensor with re-manufactured one and problem was corrected and code has not come back.

[justinvolvo70]

From what I understand from the owner, the problem has been around for a while. No codes yet.

[justinvolvo70]

Well I know that my brake booster is bad. It has developed the vacuum leak that can be heard from inside the cabin. When it's at idle and foot off the brake, you can hear a vacuum leak under the driver's side of the dash. As soon as you depress the brake pedal, the vacuum leak stops. I've read on here that that's a common problem with these cars. Im wondering if that vacuum leak is contributing to the fluctuating idle as well. However, i kinda doubt it because it isnt a huge vacuum leak and depressing the pedal doesnt correct the idle problem.

[jjaV70T]

Vacuum leaks can cause engine drive ability issues..for sure,,get the booster replaced asap..