Gee, the GM lovers should read this thread and stop going on about the Honda transmission of the month club huh?
My review of the 06 GXP is almost identical! The smallest rock ever cracked my wind-shield the 2nd day I had it, $2000+ transmission repair at around 68K miles, water leaking inside, XM stopped working, brakes all around, tires all around, both remotes stopped working. It averaged 13-15 MPG no matter what, yada yada.
You can read my post labeled "Nightmare". Purchased Nov 08 and stopped driving it Dec 09. I was sent to England to work Jan 2010, but was terrified to have the car shipped over so it's been parked outside my friends house ever since!
I've doubled up on payments so I can dump this car! If only the retail value would stop falling! I owe $12200 as of July 2010, once I get the wind-shield replaced I'll start ringing up dealerships to buy it from me.
I don't have the heart to sell it to another person! Just thinking about it again drives me insane!
Good luck trying to get anything from GM. I bought my 2000 GP new and went through the same transmission problems when it had only 38,000 miles on the clock. GM refused to pay for the repair because the car was 2,000 miles over the warranty. Back then it was a lousy 36,000 mile guarantee. My GP had many serious and expensive breakdowns, all occurring before the car even reached 50,000 miles and all at my expense. They opened a case for me also, but continued to do nothing as the breakdowns continued. Looks like years later, nothing has changed at GM.
Well I got new tires at the end of the summer, and just 4 months later the wires are already showing. I bought the car in 2008, and I only get about 10,000 miles to my tires, if that! I have had it lined up and looked at, and they just tell me that it's just how the car is made! I HATE that I've got to buy tires all the time!!!
I've heard different things over the years regarding the V8 W-bodies (Grand Prix, Lacrosse, and Impala SS), because they all seem to have catastrophic transmission failure at least once prior to 100K.
The best theory I have heard is the V8 generates much more heat than the 3800, and this extra heats contributes to the transmission failure.
Another school of thought is since both engines are routed to more or less the same transmission, the additional power produced by the V8 wears out the transmission faster.
A quick look to Wikipedia on for the Lacrosse reveals: "Power is routed to the front wheels via a 4T65-E automatic transmission (4T65-E HD on Supers)."
So the V6 and V8 basically share a transmission, with one being a quote 'HD' design (whatever is heavy duty about it, I can't be sure)... Keep in mind the W-body and its power train were never designed to accommodate a larger engine than the 3800. The platform was 'enhanced' for the 2004 model year, so GM could offer the V8 FWD option.
My thought is avoid the V8 W-bodies, and stick with its intended power train, if you are looking for long life from your Pontiac/Buick/Chevy sedan.