Quote Originally Posted by 89Vette View Post
The vibration I'm talking about is definitely more than you could sell a new car with (and enough so that I can comfortably classify it as an "issue"). It's also enough that it would drive me toward a solution (or sale if never corrected). It's one that creates cabin resonance at hwy speed where passengers are annoyed (mainly in the back seat). But, it's definitely coming from the motor (since it is present when parked).

After reading Jerry's response, I tend to think this is a motor mount issue. Plus, the current owner had the belt removed, checked for balancer play, and if the vibration still existed w/o the belt. It does and there's no play.

That pretty much means it's the mounts (or the motor). When/if I can confirm the mounts, I'd like to purchase the VX in question.

The downside is the same shop said they did not see a problem with the mounts either. But that's probably harder for the average mom/pop wrench-turning shop to determine. It's one of those areas where a (dealership that's seen more specimens) might better diagnose. OTOH, lots of dealers have seen very few of these!
Maybe this 6VE1 really isn't very smooth. I saw another 3.5L motor today. I went back/forth between both motors. They had (close) to the same vibration/harmonics around 2500rpms. Both smoothed out between 3500-4000rpms though one motor was noticeably smoother than the other. (Not a lot, just noticeable.)

Maybe this really is a combination of the motor's "character" -- plus a bit of mount vibration. It might also be that one needs plugs and/or injector cleaning to recover maximum smoothness.

Has anyone ever looked into installing new mounts and/or trying the heater hose trick relayed by Jerry?