Trailblazer Vibration at Idle

[Nick1994]

My grandma's 2002 Chevy Trailblazer LTZ 2wd 4.2L I6 has a bad vibration in drive when stopped. Goes away in neutral or drive. All points to the motor mounts but they don't look horrible and they don't have a lot of play when going from reverse to drive and back. The motor runs perfect, I'm thinking it could be motor mounts, or maybe exhaust vibrating or? The car is immaculate and always taken care of and has just crossed 98k miles. What do you guys think?

 

[SteveSRT8]

It could also be the trans mount.

Note that IME they can be very hard to diagnose visually. But they are aging parts that can fail due to time elapsed regardless of mileage...

 

[SatinSilver]

I think I'd start by cleaning the throttle body if it hasn't been done lately. Maybe even add some Redline fuel system cleaner. Then take it from there.

 

[CBR.worm]

If the idle is slightly high or low they will vibrate. Does it go away if you give it a tiny bit of gas

 

[MolaKule]

I have to have the induction and fuel injectors of our daughters '06 I-6 Trailblazer cleaned before the vibration went away.

Vibration was worse when cold.