marvowen said:A month or so ago, I wrote that my new 2005 XLR was disappointing me due to a bad vibration as I accelerated briskly. I mentioned that it was bad enough that it tickled my fanny through the car seat. As you might expect, I got some interesting responses by using that description. I promised to write again when I got to the "bottom" of the problem.
I called the GM Tech Center and was directed to two gentleman who had me bring my car to them so they could take a look. This is only an hour drive for me so I was eager to have them look. The one gentleman drove and we only went a block or so before he told me that he knew what the problem was. There are three different positions for the torque converter to bolt up to engine output. There are marks to line up and sometimes the plant misalligns the parts. This allows two rotating imbalances to be linked together, amplifying the imbalance. The vibration was worst at just over 3000 RPM. The dealer re-aligned the converter and the problem went away.
It appears I have a similar issue on 2004 and I am inquiring at what RPM you experienced the vibration.
I first thought it was an Exhaust Resonance issue as experienced on my C5.
Your comments please.