AJ'S 88NA;942872 said:Hard to say at this point. I would pull it and see what's what. Then decide what and how far you want to go with it. You may have to have the block bored which would mean new pistons. As far as guessing how much it will cost would be a crap shoot right now. I'd call around to some shops and try to find one that has worked on the 7M before.
Before you pull it Jdub had a few suggestions to the problems you have I'd check those things out first.
Why were you going to do a HG in the first place when you haven't done a compression test? The problems you have don't seem that bad, unless you just want to rebuild it.
I don't think I'm going to go the rebuild route, it seems pretty expensive and as for just wanting my car running optimal for its age as it doesn't seem like an economic option unless I want a few more horsepower. Also being my car barely can keep up with a 92 Oldsmobile Cutlass there is definitely a significant power lost.
I was going to do the HG because of a couple of reasons. One being the notorious BHG in which seems everyone eventually encounters and its more of preventative maintenance. Second, I've seen coolant on the plugs and there was signs of burning coolant when I pulled my plugs last. Third, I want to replace every single gasket, seal, and hose possible. Finally, as for the problems I've listed it would give me a great opportunity to see what is happening inside my cylinders as well as replace any part that warrants replacement. While I have the optimum amount of time, I want to be more familiar with a motors internals as I have a natural curiosity being an engineering student.
I haven't gotten a chance to check the codes today as I woke up way late for work, going to try to push it tomorrow so we'll see.