That is a lot of miles. I am about to drive my into the ground because mine still has the noise in the engine but I now know that is a problem that a lot of 3.1'* has and that is the camshaft problems. I had to re due the intake on it last month and I pulled the lifters out and had a good friend turn the engine with a breaker bar and I noticed some wear on a few exhaust lobes on the cam itself. So now I know why the engine noise travels threw the exhaust system along with the performance problems the engine is starting to have. So I really don't think the car will see 100k miles before the engine blows in it. It just rolled over to 91K last week and I bought the car with 79,500 on it. But for the most part I have gotten my moneys worth out of the car. If I thought is was worth it I would just pull the engine and overhaul it but it'* now worth it. To many other problems wrong with the car to do that kind of work to it.
1996 Oldsmobile Achieva SL
White 4 Door