3.0 idle after driving and put in park ?

[87supraman]

Im on my lunch break and searched through 18 pages so I apologize now if this has been addressed multiple times! I must say threads with 3.0's are few and far between. My wife has been driving my car for the last couple months... sad I know. But she nanny's for a family with 5 kids and I would rather put them in my avant than her volvo c30.

Well here is the problem. I hear her come home everyday and as soon as she gets in the garage and puts the car in park the car idles high and back down to normal, up and down, till she gives it gas and then it smooths out. All 6 coil packs were changed out a few months ago along with the timing belt. Also during the timing belt most of the vacuum hoses were changed out. I do not have a lot of time to diagnose the problem till the weekends so any ideas would be great. Thanks!!!!!!

[Greedo]

Mine does the exact same thing. To my understanding it's something with the throttle body. Mine had a throttle body adaptation (or whatever) and it went away, for two days, then it came back. I also have heard (can't state if there's truth or not) that the intake has something to do with it (MAF/O2s). My MAF and B1S1 O2 were recently replaced and then my B2S2 went bad. I'm not sure if that has anything to do with it, but have been told it can.

Anyhow, it's rather annoying, but thus far I have yet to find a resolution that actually works.

[AvantinUSP]

i get the same thing randomly every now and then. never figured out the problem. I'll give it a bump.

[JoshDub]

How did you get your car into the kitchen?

[87supraman]

Super bump/follow up. I never did figure out what was causing the strange idle after driving and putting the car in park.
But last month I took off the intake manifold chasing a coolant leak. Now after reinstalling it the problem is gone. It's been over a month so I figured it's safe to say the issue is resolved.
The only vacuum line I changed in the process was two that connect to the check valve under the 0000 rings cover. It is on the left side of the throttle body if you are facing the car. I replaced the normal sized vacuum line that goes from the check valve down under the little tray that sits on top of the throttle body. And the bigger one that it sticks into. Hard to explain, I will add a picture tomorrow. No idea if changing those two lines was the fix of this issue. But no other parts were changed. So try that if you are getting that strange up and down idle speed after putting the car in park.

[SlickFix]

I bet it was changing those vacuum lines. As I was reading this thread, I was thinking vacuum leak the whole time.