Our 2009 Matrix has a problem that I can’t quite figure out.

Seemingly at random it will develop a vibration. The vibration only exists while on the throttle, as soon as you let go of the throttle it disappears.

Because of this I am assuming it is the driveshafts/CV joints. The wheel bearings seem fine since there’s no play in the wheels and no weird noises.

What I can’t figure out is how to confirm that it is the driveshafts/CV joints and how to diagnose which driveshaft is the issue. There are no noises like clicking while turning that would normally give away a bad CV joint. And the randomness of it is weird. After the first time it happened I took it to work the next day to get the wheels rotated and balanced just to rule those out and it didn’t happen at all that day even at freeway speeds. So far it only ever develops at freeway speeds (70mph+) but once it does develop will show up even at speeds down to 40mph. It then seems to “reset” after it sits for the night and won’t develop again until at freeway speeds (granted my data sample is small).

EDIT: Also took a look at the motor mounts and they appear to be okay. Not sure what one does to check if they are good besides a visual inspection.

What does Oppo think?

Suburban for your time