Looking at picking up an 05 STS4 tomorrow for around 19,500. The car has about 60k miles and is a one owner car with no accidents, all original paint etc. It appears to be a 1SG car with everything. Don't know about HUD and ACC, don't particularly care except for ACC which would be nice. It does have the sport package wheels and tires.

The main issue I noticed during the test drive is there seems to be a noticeable groan from the bottom of the car between 10-35mph. This definitely feels like something in the AWD system or the front differential and could be a very costly fix. Just trying to get an idea whether anyone has any idea wtf is wrong with it. Other than that and needing new tires it was beautiful.

Also, if damage has occured as a result of the seal leak, will the dealer repair the damages in the differential as well as part of the recall?

I would keep looking for a car under 50K miles and Cadillac CPO.

As usual with my deals the price of the car is really important here. In order to absorb the negative equity I want to carry over and not owe an insane amount, as well as the favorable amount I am getting for my trade I need to get this one or skip STS's altogether.

Looking at picking up an 05 STS4 tomorrow for around 19,500. The car has about 60k miles and is a one owner car with no accidents, all original paint etc. It appears to be a 1SG car with everything. Don't know about HUD and ACC, don't particularly care except for ACC which would be nice. It does have the sport package wheels and tires.

The main issue I noticed during the test drive is there seems to be a noticeable groan from the bottom of the car between 10-35mph. This definitely feels like something in the AWD system or the front differential and could be a very costly fix. Just trying to get an idea whether anyone has any idea wtf is wrong with it. Other than that and needing new tires it was beautiful.

Also, if damage has occured as a result of the seal leak, will the dealer repair the damages in the differential as well as part of the recall?

Ask them to allow you to take the STS to a Cadillac dealer for an inspection. Most dealers will do a full inspection for around $100 and list everything thats wrong with a vehicle. I have done this in the past and in many cases was the best $100 I ever spent. Walked away from a few deals when they came back with large lists of problems.

If the $20K price range is important, there should be a number of CTS and DeVille / DTS CPO units in that price range. You can also find some certified V8 Lucernes (CXL or CXS) in that price range that should still have some 4/50 warranty left. A certified LaCrosse CXS is also a nice ride and even less expensive. If you want added warranty with the Buicks, buy a GMPP contract from Black.

I may consider going ahead and doing the Caddy inspection like Tomm said, that should uncover pretty quickly whats going on under there. I do have to say that other than that issue the car was in very nice shape.

If not maybe I'll wait on another one to come around, I'd be perfectly satisfied with a non-AWD as far as Im concerned. It seems like every once in a while a local dealer will use an STS as a "get em in" internet special car regardless of options or mileage.

Or make friends with a local dealer and tell them what you want and have them go to the GM auction and get you one. Tell them you will give them $1000 - $1500 over auction cost and you will get yourself a nice vehicle. There are tons of 2005's going off lease and there are lots of them at the GM dealer auctions.

Well this threw me for a loop. Turns out the groan I was hearing isn't an undercarriage issue afterall, it's actually something motor related. I drove it again today and put it in neutral and revved it and it was groaning. Yet when I got out to check the engine at idle it was idling smoothly. I don't know if it could be AC compressor related but I forgot to turn off the AC to check. Who knows.

I like this car alot so I'm holding out hope for it still, but if I can't figure out where that noise is coming from or get it inspected I'll have to pass.

I did find it amusing that when I stuck my nose down in the engine bay I managed to get a whiff of the ever present coolant smell. Not as much as in the old N*, but it was definitely there. Some things never change I guess.

Check out some of the deals my buddy has:

http://wwwheels.com/cfapps/car.cfm?ID=2167942

http://wwwheels.com/cfapps/car.cfm?ID=2173374

http://wwwheels.com/cfapps/car.cfm?ID=2173325

You do not need the AWD in Florida ;) If you live where I do, that would be a reason to buy it.