I tried to swap out my thermostat the other day and one bolt came out fine, but the other gave me a few good turns, and then became very tight. Obviously, I don't want to snap this thing off inside my manifold, so are there any procedures that I can try to get it out in one piece? Maybe some heat? I guess my only other option would be to drill and tap it? Any info is greatly appreciated.

 

Or maybe it's time to upgrade the stock intake......

 

"If at first you don't succeed, apply brute force."

 

Heat, lube repeat until its loose. Then use a thread chaser and antiseize on the new bolt threads.

 

soaking down the bolt with pb blaster and applying direct heat with a propane torch after you get the bolt real hot you can shock with a hammer, do this several times and even heat it up and press a hammer on the bolt the heat will dissapate toward the manifold hopefully loosing the threads. If you are able to remove it clean the bolt or stud threads real well and use antiseze on the threads.

 

Hey thanks. Will do

 

Let it soak in PB blaster and instead of just trying to remove the bolt turn it back in some then back out a little more than before,turn back in then out, then again and again until you get it.

 

Yes ronusmc. That was exactly the method I was using when trying to get the bolt out. It seemed to not be progressing any farther using that method, so that's why I think I need to try the propane torch and possibly the hammer procedure as tunedperformanc has described. It's definitely worth a shot, but the last thing I want to do is snap this thing off in the manifold, cause this isn't a project car. This car is a daily driver, and my only means for transport right now.

 

I just went thru this last month when changing mine... Snapped the inner stud... Ended up grinding the top flat with my dremel and drilling out the bolt starting from a very small drill bit size dead center and progressing up a size until I got to the correct size down for my tap,,, then simply tapped out the remaining threads of the old bolt... I then used stainless bolts from the local hardware store when reinstalling with antiseize... Take your time if you do snap it, not all is lost... Didn't take that much time if you have the correct tools... Next is my distributer hold down bolt which feels the same... I'm only 1 degree off in my favor, so, I probally just leave it... Hopefully you'll get it out, but if it does snap, plenty of options to save it..

 

As a last resort, since you can get it to turn you might be half way there. You could grind the head off, take off the housing and just turn the bolt like you are tightening it until it drops into the water jacket, then remove it thru the thermostat hole. Anybody see any reason this won't work? I don't know how much bottom clearance their is or how hard it would be to grab the bolt shank one it dropped into the water jacket of the intake.

 

Uh yeh wont work

 

Well, tell us why. Is it too long and will hit before it drops out, or what exactly? He seems to have it loosened, it just won't back out because of rusted threads hanging in the water jacket.

 

The thermostat bolts should be into casted bosses.

 

Ok, I figured his wouldn't back out because the threads sticking into the water jacket were rusty and that's why it would jam when trying to back it out. But I guess they don't stick into the water.

 

I've broke them before, drill and retap is about the best bet. If I had the time I'd install a couple of studs in the intake and then hold the waterneck down with nuts rather then the bolts so even if coolant gets down in the threads and corrodes it up i'll still be able to get the housing off no problem.

 

OK, It's easy. If I can't get it, It's drill and tap, or new manifold. Can I drill and tap while leaving the manifold on the engine? What are the consequences of drilling it out with the manifold still on the car?

 

only if you drill to deep

 

Ok, thanks, but wont the metal shavings get caught up on top of the piston? Or will they blow through

 

you will be drilling into the valley if you go to deep.

 

Hopefully you'll get it without having to resort to drilling it out. but if so, I just took the water neck, put the other good bolt thru the hole from the top side, put my drill bit on the bottom side next to the bolt threads for depth, wrapped some masking tape around the bit at the bottom of the bolt threads and went to work...

 

Ok, I know what I have to do, but may not do it till spring. Thanks everyone. You've been many helps