shudder at 45mph

[Desert Dan]

Take a look at your tires to see if there is any strange wear of cupping?

Does it change with RPMs or throttle?


does it happen on concrete or asphalt?
In CA many of our concrete freeway expansion joints that cause a bounce at certain speeds but not a shudder?

[Highrisk]

From what I've seen, its independent of the RPM's.
Also - when we decided it had to be real was when driving on a freshly re-surfaced road. It's been acting this way for about two weeks.
When the AC and recirc are on, I've noticed a smell - that I think is antifreeze. Coincidence? Maybe.



Oh, but it gets better. She just called. She's leaving work, and the check engine light and the traction control lights are on. It's displaying
"Traction stabilization reduced power service stabilization system traction fail"

This would be the second time her stabilization system has malfunctioned and required repair. I doubt it is related to the shudder.. but who knows.

[ChiHummer3]

Well....at least now you know it's going to the dealership. Let them figure it out.

Good luck!!!

[Highrisk]

She took it in once before for the post-head-change shudder. They said it was pretty far out of alignment, so they "fixed" it.
Funny, I didn't feel any pulling or other alignment problems before. Why would a new vehicle that's been dealer maintained be out of alignment with 10,000 miles on the clock? The tires aren't cupping, nor do they show any irregular wear patterns.

Regardless... they re-aligned it, and it didn't fix anything. We'll see what the techs say tomorrow.