My dad has a 2000 Bonneville. I have noticed some leaking oil on the ground, and it looks like some antifreeze junk appears to be evaporated under the oil cap. First thing that popped into my mind is head gasket. I talked to him about it and he said he knew about it and didn't think it wasn't a head gasket. I guess the dealer said something about a different gasket.

I know there are some common problems with the 3800 and I don't think a head gasket is normal and he drives rather conservative.

You can probably tell what it is, if you could give me a wirte-up for it and a parts list that would be great. I'm going to attempt to fix this up since he got a new car and I will probably be using it for college.

Car has ~130,000 miles btw. Gas gauge is broken and I might try to tackle that DIY also. Any common things that go wrong that would be easy to replace would be great.

It needs a tune up too since my dad has pretty much neglected maintenance on it. Spark Plugs, Fuel Filter, Air Filter. Am I missing anything else

Welcome to the Bonneville forum

Head gasket is unlikely. More likely it'* a LIM gasket. Here'* a write up about changing them. https://www.gmforum.com/t278911/ You should be able to find a write up for more things in the tech info area. If you have any questions feel free to ask. Also, please add your cars year and trim level to your sig to better help us out.

How hard is this gasket to replace? The only car I have worked on is my '99 M3 and it is really easy to work on. Inline-6 vs V-6, so I'm guessing it will be similar, only 2 sides?

User CP, then under settings and options choose edit signature.

Doing it isn't to bad. Just set aside a full day on a weekend.

Yeah I'm retarded. I read over the part where you said sig.

It will not need to be driven for a while so it can sit in the garage until I get it completed. Is the SSE version different than the SLE other than the supercharger?

Not as far ans the LIM gasket goes. But if your not supercharged it could be your UIM that'* the problem. I thing Toddster and Billboost will have better answers for that.

Most likely it'* UIM/LIM related. My suggestion would be to swap out the UIM with a Dorman or APN replacement kit and the lower intake gaskets while you are there with GM dealer LIM gaskets. Reason to use Dealership parts on them is they are aluminum frame and fel pro is still make plastic frame. Plastic has issues and you don't want to do it again down the road.

Intense-racing and ZZPerformance are also good sources for those gaskets.