PontiacBonnevilleClub.com

Hey everybody,

I'm looking to get back into a Bonneville, and have what sounds like a really good deal. I have the opportunity to purchase a 98 SLE in good shape but it has slow antifreeze and oil leaks. I haven't had a Bonneville for almost 2 years, but I know the antifreeze leak is something to worry about. The seller isn't sure if it's an external or internal leak, which is what I'm afraid of. The car has 186xxx miles on it, but he said he had the head gasket replaced on it at around 75k miles. I'm not sure what coolant he's running, and the car has been more or less sitting in his driveway for the past 2 years.

Can I get some suggestions on what to look/listen for? I'm really considering getting this car, but I don't want to buy it and put a whole new engine in it a few miles down the road....

Here's what I know:
- Engine stared/ran fine for a good 5 minutes. No weird noises or clicks.
- Engine smelled fine before/during/after running, didn't leak any fluids (coolant was pretty low).
- No smoke in the engine bay or out of tail pipes.
- There WAS a dark spot on the driveway under the car, confirming the oil leak, but couldn't tell if there was any external antifreeze leaks as there were no wet spots on the oil.

I'm looking for any and all opinions here. Just want to be sure I'm getting a car that I don't need to throw money at... that's all. Thanks!

Head gaskets are never the issue on these motors. I'm willing to bet it needs either LIM gaskets or an UIM or both. That's where I'd guess the coolant is going.

The oil might be seeping from the oil pan gasket, or from the rear valve cover. Both things you'd miss just from looking at the engine bay.

Already a solid response. I like it.

The car has been driven sparingly (by sellers account) for the past 2 years because of the leaks. Guessing 5k or less has been put on this engine, what am I possibly looking at as far as possible internal damage? A little? A lot?

I know all this is purely speculative, I'm just trying to cover all the bases, that's all.

There might not be any internal damage, as long as the coolant hasn't been seeping into the oil. Check the oil for sparkles under a powerful light. That'll let you know if there's bottom end damage.

nos4blood70 wrote:There might not be any internal damage, as long as the coolant hasn't been seeping into the oil. Check the oil for sparkles under a powerful light. That'll let you know if there's bottom end damage.

Hmmm... interesting. How powerful of a light? And could that be done during the day, or would could it only be done after dark?

Either way. A good flashlight. Or an LED phone flashlight should be good enough.

Hmmm... alright. Thanks for that tip! I'll check it out tonight probably.