My friend has a 2000 GTP supercharged with 250k miles. I drove it for a week or so and found the car to be in good shape despite the mileage, however it had no heat. In return for letting me borrow the car, I installed a new thermostat since the old one was stuck "open" and not allowing it to get hot enough. As soon as I did this, the car had heat, but it was also pumping out coolant from all over the motor! Heads, intake, water pump. Big mess. Turns out this car (which he gave $700 for) has some serious "daddy issues."

Well, he's trying to get rid of it. I liked the car so much I'm considering buying it as a spare car for the wife and I. However, it sounds like resealing the motor is a nightmare and probably not worth it. I've never done a head gasket job and I have a feeling that this would not be a good car for a first attempt. I priced some replacement motors from the junkyard with mileage in the 100,000 range for around $800 plus $400-600 for installation. What all would be needed for the swap from this super charged motor to a naturally aspirated 3.8 or 3.4? What range of years are swappable?

It would NOT be worth it to go down to the naturally aspirated engine or the 3100 engine. Any supercharged 3800 from 1998 to 2003 will bolt right in. I'd get one from a GP or a Regal because engine mounts and things from a Bonneville/88/Park Ave or a Riviera are different, though the engines themselves are identical.

Once these engines are out of the car, it isn't a bad job to replace all the gaskets from the head on up and the water pump. Depends on how mechanically inclined you are, and what kind of tools and time you have.

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One Big Ass Mistake America

Is it worth pulling the motor just to reseal it? I have not checked prices for resealing, just swapping in a different motor. But with 250k, I don't want to pay to have it resealed only to have it fail elsewhere.

I think it would be advisable to pull the spark plugs first and see what the cylinder walls look like. Even with a salvage yard engine, I'd pull everything down to the lower intake manifold and regasket it anyways, since the lower intake gasket is a VERY common failure point. In fact, that's likely where yours is leaking from.

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One Big Ass Mistake America

I guess I'm not all familiar with these engines. What's the difference between the lower and upper intake gaskets?

Here you go:

http://www.cpaclubgp.com/misc/lim-gasket.html

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2005 GT owner [Non S/C] with a "big DIC".
Two years later and I still love the car.
Thanks Pontiac...Bleen is keen!