: Vibration on strong acceleration / Suspension feel



TulsaVic
03-17-11, 02:44 PM
I'll be bringing my car ('08 Performance) in shortly for it's once a year oil change and am wondering if I should raise these items: When doing a full throttle acceleration from around 20mph (so the transmission kicks down to first gear), there is a noticable powertrain vibration that remains, as the transmission upshifts, until I lift my foot from the pedal. At a steady 65 - 75 there's no vibration at all. And no vibration during more moderate accelerations.

Also, with the suspension, when going less than 20mph, on a road that is relatively smooth except for the cement seams or cracks (i.e. no potholes or patches), the suspension seems harsh and a bit noisy. Going down the same road at 30+ mph I don't feel the same harshness or hear the noise.

Anyone experiencing similar? I do have a sensitive butt and tend to be picky with my cars. Only 29K on odometer.

RicktheRealtor
03-17-11, 04:59 PM
If you're on a fairly smooth raod, you should actually not hear much of any suspension noise or feel harshness. Do you have any leaks coming from the front struts? My first thoughts are to check the tires; they may contribute to harshness, but usually the other way around (ie at higher speeds).

As far as vibrations with the drivetrain on acceleration, check the engine mounts. You only have 29 K miles, so it's unlikely to be mounts. But I once had a Caddy technician tell me that if you have any engine oil leakage and it finds it's way to the mounts, the rubber quickly deteriorates.

Obviously, check the least expensive possibilities first. Good luck. I hope it's nothing too serious.

Superjim
03-17-11, 05:22 PM
I'll be bringing my car ('08 Performance) in shortly for it's once a year oil change and am wondering if I should raise these items: When doing a full throttle acceleration from around 20mph (so the transmission kicks down to first gear), there is a noticable powertrain vibration that remains, as the transmission upshifts, until I lift my foot from the pedal. At a steady 65 - 75 there's no vibration at all. And no vibration during more moderate accelerations.

Also, with the suspension, when going less than 20mph, on a road that is relatively smooth except for the cement seams or cracks (i.e. no potholes or patches), the suspension seems harsh and a bit noisy. Going down the same road at 30+ mph I don't feel the same harshness or hear the noise.

Anyone experiencing similar? I do have a sensitive butt and tend to be picky with my cars. Only 29K on odometer.

About the vibration under full acceleration...I would take the service writer or the tech that's going to work on it for a ride, so they experience it WHEN YOU DO and acknowledge it.

At the same time, you can demonstrate the suspension harshness and noise.
I am guessing, but, at over 30mph, the MRC is probably smoothing everything out...but there should still be some noise, I would think.

I had to have both front strut bearings replaced on mine a while back.

Texas Jim

BamaBSC66
03-17-11, 06:02 PM
I had exactrly the same problem with my 08 Performance DTS. problem was in the right front CV joint. it was disintegrating and the tech said it was a common problem. Replaced the front axle assembly and all is well.