Co-worker has an '06 TL Auto that he says as it shifts into fourth at exactly 51 mph he feels a real roughness or vibration thru the gas pedal. This is in every day driving, racing or whatever. Anyone heard of this problem before? Thx

 

Edit: Sorry I meant to say "not racing or whatever"....

 

It's actually shifting into 5th gear and it's a know minor issue with the TL. Apparently when it shifts, the engine harmonics cause a minor drone/vibration. There was a TSB out for this issue where an engine damper was installed to help reduce it greatly.

I had the TSB done on my 04 and it helped greatly in reducing it, and with time and more miles it's gone away completely!

If you feel that it's excessive, I'd probe into certain aspects of the car such as the fuel being used (should be 91+ Octane), and as well check the all the fluids in the car, and as well check the motor-mounts.

Also ask your co-worker if they are sitting at a redligth if they can feel a vibration in the car. If the answer is yes, more than likely the problem is the motor-mounts and they either need to be replaced or neutralized.

 

OK thanks.