Updates and Issues

Haven't posted in awhile. Basically, I've had my GT 3 years now and I'm just getting around to fixing some things on it. Everytime I look around I get surprised by something stupid the previous owner did. Anyway, my latest discovery led me to replace the intake with a BBK CAI. It breathes so much better and I no longer have to worry that the air filter fell off while driving. (Thats another story.) Also, I went ahead and put some cheapo spark plugs in it as a quick fix to the problem I was having with her missing. She was running great for a week and a half and felt brand new until yesterday when she decided to overheat and leave me stranded. I let her cool for about an hour, poured some 50/50 coolant in her and made it home (10 miles) and she began getting hot as soon as I was parking. I'm hoping its the thermostat so I'll check that first. Anyone have any suggestions, the radiator is less than 2 yrs old and from what I could tell the hoses seemed ok too.

Thanks for the advice. I'm gonna work on it this Wednesday and hopefully that fixes it. She has a lil over 200k miles and I've fixed/replaced the clutch, spark plugs (cheap ones for now, better ones with wires coming soon), brakes and rotors, exhaust, radiator, alternator, battery, cold air intake, fuel filter, and serpentine belt. Anything else I should look for while I'm messing with her Wednesday?

So I changed the thermostat out today and boiled the new one to make sure it opened. It was only $15 at Auto Zone. Anyway, it was pretty easy draining the old fluid (it was still bright green-this is good) and taking out the old thermostat. When I put the new one in I used a felpro o ring that I also got at autozone and I sealed it with some thermostat sealant. I filled the radiator back up with 50/50 coolant and started her up and noticed a leak coming from one of the bolts in the thermostat housing. I don't have a torque wrench but after tightening it up as tight as possible I noticed that the leak went away but I could see it getting slightly wet at the housing itself but not the bolts. I let her run for about 15 minutes and it didn't leak or get anymore wet than it was. I also drove up the street but then the radiator light came on and she began running hot (well where the "A" is in NORMAL) I checked back under the hood and still didn't see any leaks, just where it was starting to get wet at the housing which was the same as it was before. I checked all the hoses too and no leaks anywhere.

Why is she still getting hot if the new thermostat works and the o-ring is in place and has sealant? Should I put sealant on the housing itself? Could it be because I didn't tighten the bolts to 18 ft lbs? Any advice would be appreciated. Would love to drive her this weekend!

I think I recognize what the problem is. After going back through my steps and relooking at the Haynes manual, I realize that I put the o-ring on first and then the housing. And I used sealant and the Haynes manual says not to. Apparently the o-ring goes on top of the thermostat and not under it. This and the fact that I used sealant may be why its still running hot. The old thermostat had a gasket underneath it that I had to scrape out which is why I thought the o-ring went first.