I have noticed our '08 sometimes taking longer than normal to shift up between 3rd and 4th. Right about 45 MPH it seems the like I accidentally dropped it into I instead of D.....I look down but it's in D. Then about 55 it finally shifts up (actually pretty hard). Each time this has happended it's a different condition, slight hill or even flat. This is the second HHR we've owned and our first one shifted smooth, barely being able to feel shift points.

And also sometimes we hear a klunk coming from the rear almost like we bottomed out or a spring slipped out of its mount. This happens when we might go over a uneven road surface or in/out of a parking lot.

TIA for any help.

 

sorry for the old bump, but how did this turn out?

our wagon has started to shift like this.

 

It still does it periodically under different driving circumstances. So I never know when it's gonna do it. And I haven't had any other serious problems to justify taking it to the dealer, and you know it probably wouldn't do it when the dealer had it.

 

Sounds like shift shock. PCM may need a reflash or an update.