my tstat was stuck open and when reinstalling a new tstat and gaskets the housing would not install flush...the felpro oring on the housing fits nice and tight...the gasket for the tstat and housing seems to be the problem...the felpro version is much thicker than the original...i went to the dealer to get an oem gasket but they gave me something completely different and the gasket goes around the tstat???

so i started to disassemble the throttle body so i could push the housing down directly from above...its becoming a real pita...some vacuum hoses ripped and i cant disconnect the throttle body pipes to seperate it from the intake manifold...whats the best way to get it seperated?

does anyone know where i can get a new oem tstat to housing gasket? like i said before the dealer searched by my vin and that was the only gasket they showed and was completely wrong

It helps if we know your cars year and trim level. Do you have a local autozone or advanced auto or some other shop like that. I have gotten a few thermostats from there with no problems at all. If I remember right, some newer cars, 00+ only need the Oring around the thermostat. There should be no reason at all to remove the TB to install the housing. I have a write up here somewhere, I'll find it and add to this message.

https://www.gmforum.com/t277853/

90 sse...it is the one bolt housing and two gasket type...one o-ring goes around the water outlet housing and the other goes bewteen the tstat and housing...ive searched and have found similiar problems but if i remember correctly they all reused the gasket or left it crooked...im trying to get it on straight and with new gaskets...i did go to napa and they have a different tstat to housing gasket that most resembles oem but is not the same but it might be better than the felpro ive been trying to use

You should pick up a tube of peraseal as well. Put a thin layer on each side to seal it good. There'* another Moderator here, 1993 SLE, he'* the guy to ask, he knows his stuff with the older cars.

well i got everything apart and need to replace at least one steel tube for the throttle body and the napa tstat gasket seems to fit well but i also have direct access from the top to compress it down

You need two seals.
GM pt# 12337860 in group 1.154
GM pt# 12337901 in group 1.252

I will double check these at work tomorrow in case I'm brain farting right now, but you need an o ring for the housing and you need a seal for the actual stat. Don't ask me how I know. This is for the C engine code by the way. Also the single bolt Housing is almost impossible to seat it squarely but don't worry too much about it. It won't leak.

I have the Stant brand stat seal hanging on the wall and the Stant part # is 27277
I have a Fel Pro brand housing O ring, also hanging on the wall and the Fel pro pt# is 35608

Hope this helps.

You need two seals.

GM pt# 12337860 in group 1.154 = Housing (Goose neck) O-Ring

GM pt# 12337901 in group 1.252 = Thermostat Seal.

Greeting all. I have a 1988 Bonneivlle LE with engine 'C'. I replaced the T stat with Stant. The car still didn't warm up. If I let it idle for a while it would reach 180 degrees but once I started to drive, the temps would fall to about 110-120,

So I got a Tstat from the dealer and noticed the new Tstat had a Oring around the Tstat. I tired to put the Tstat in but it seems with that seal around the Tstat, it was too big to go in. Do I have the right T stat?

The part number on the box reads ACD# 131-115 GM# 24506986

Maybe I'm supposed to take that seal off the Tstat and place it on the engine block before I put the Tstat in?

The other O ring you see in the photo is one I got from Pepboys. That'* what their book called for.





Maybe if I put that smaller seal on to the Tstat like this and removed the seal that came with the AC Delco Tstat it would work?




What do you guys think?

The O ring on the goose neck housing (the one held down by one bolt) is fine.

If I get this seal, does it go on the block first then place the Tstat in or do I place the Tstat in and then put the seal on top of the Tstat.

If it were my guess....I'd say the seal goes in first then the Tstat goes on top of it and then Goose neck on top of the Tstat.

the seal that you got from the dealer is wrong...i went through the same problem with the dealer...the one from pep boys is the correct type but the one i got from napa fit better...there is no way to get the tstat in with the gasket from the dealer that goes around the outside of the tstat...so put the seal you got from pep boys as pictured and take the dealer gasket off and thats how it goes...so you replaced the tstat without that seal right? the t housing installs relatively easily without it so when you use the pep boys gasket it becomes a pita to install so if u can try to get the napa one because it is thinner