[videodroner]

Hello Everyone... New member here.

I've been noticing a problem lately with my 2008 Ford Mustang V6.
Whenever my car is parked, the motor runs fine, but then the RPM drops down to around 500 and it does a weird shake/vibration and then it goes back up to normal.
What could be the problem? I'm afraid to drive it.

Thank you!

[Keving]

Vacuum leak? O2 sensor? Some type of emissions crap?

[Animal's 3rd]

That happens to my car sometimes, but only when I come to a stop. I still haven't figured it out yet cause it is very erratic and I'm never able to just make it do it. Just like that dang clunk I hear once in a while coming to a stop also.

[stars]

Loads switching on like the AC compressor or the cooling fan can cause a momentary change in RPM at idle. Mine will occasionally drop to 500 RPM when I shift from drive to park (then it quickly recovers). Sounds like your problem is worse than that though, and may possibly be in the fuel system (even a bad tank of gas might do it). I would expect a 2008 to still be under warranty, why not let Ford figure it out.