Just changed my thermostat. The engine was not warming up. Must have been going full open right away. The t-stat housing with tpi is a pain in the butt to get at the bolts. I had to use a 14 mm wrench. What has anybody else used? The aft bolt wouldn't take a deep socket because it would hit the tpi with backing it out some. I've got a water pump going I believe. It is noisy! Used the screwdriver stethoscope method. Still working. Just scary noisy.

So is your engine warming up normally now, with the new thermostat installed? I cant remember what I used, but I think I just an open ended spanner to remove the thermostat housing bolts.

It's really easy if you pop the throttle body off the plenum. I'd rather get a straight shot on the Tstat bolts then break one off in the intake.

Remove the throttle body off of the plenum... Didn't think of that. Yes, the engine is warming up correctly now.

Well I guess I'll be pulling the throttle body off of the plenum. The housing leaked. Probably didn't wait for rtv to cure long enough. I bought some universal sockets. But that still wont get to the front bolt. Why is it a "stud" bolt at the aft of the housing? There isn't a ground or anything attatched.

I guess I'll get a gasket for the throttle body. Considering it probably has never been off it is probably baked on and will be hard to scrape off.

The radiator is already drained. I changed the water pump last night. Other than the original lower hose being a pain to get off the pump and radiator it was about the easiest pump change to do. I'm letting the rtv set up real well before I put coolant back in. It wasn't so easy I'd want to do it again. It was warm outside last night(45) but a 20 mph breeze, not bad for January but I'd still rather not have to do it again. I even used thread sealant on the bolts.

A little concerned about the age of the hoses on this thing. They are all original. Date coded and all. So I changed the lower hose. But a bit reluctant to change the upper. Still looks good and feels good.
ramble ramble.

Brett in Boise

Yeah, I attempted to change mine without removing the throttle body, but I stripped the hole cause I went in a little crooked. I turned a 20m job into an hour and a half job putting a damn heli coil in it >_<

TAKING OFF THE Throttle BODY IS A MUST!!!! What usually takes me 15min on my bird, took me 2mos on my Camaro. I didn't take the time and snapped the bolt on the backside. I had to tap new threads. Learn from my bad experience and remove the throttle body.

Will get a gasket and just pull the throttle body off. Since I've already had it off I shouldn't have to worry about snapping a bolt off. But I can see how easy it would be to get the front bolt cross threaded.

Thanks!!
Brett in Boise

See if you all had a carb then you wouldent have to worrie about the silly little tbi and the plentium plate or any of that with a carb none of that is in your way ha ha ha just thought I would throw that in there

Resealed the t-stat housing. Topped off the cooling. Started up the engine. The new water pump sounds normal now. But the t-stat housing leaks worse now.

A mechanic friend of mine said he doesn't use rtv. Maybe I'll try that. Such a simple job, but it turned into a pain. Now I'll have to drain the radiator...again.

Brett in Boise

I use the blue RTV and the felt gasket. I usually let it set for a day before testing. I think a couple of hours of set time should suffice.

i too have too replace themostat, mine has carb manfold, easy job so i thought.removed hose from themo housing and found after removing thermostat housing that there was no gasket at all[orgnal motor done 69000 .86 z2 305 ] replaced thermostat and put gasket on with glue, put thermo housing back on waited for 1 day then went for drive after two hours started to leak around housing base.can any one tell me what to use that will solve problem.use gasket ?or use rtv? or try metal to meltal ?

I can't for the life of me find the part # right now in my receipt folder but Felpro makes a nice T-Stat gasket I use which is leak-free if your housing is not warped and the surfaces are clean. It's a blue thick plastic gasket with silicone beads on both sides. It's re-useable too. About $10 but worth it.
PM me if you want the part # as it's either in my truck spare parts box or at work.
Greg

I agree with Greg. I used the Fel-Pro $10 blue gasket and no leaks. You DO Not use RTV with it. I also installed a SuperStat 195. Always found its best to spend the fee extra $$$.

Felpro gasket no rtv did the trick. The housing was not "true" so that was probably a big part of the problem. I did get a new housing from the Chevrolet dealership. But did not install since the Felpro gasket fixed the leak.