Thermostat housing gaskets

[Madness]

Probably going to have to change out the thermostat in my 03 GT N/A this week as the heat is not very good. After looking up parts on Napa and Rock Auto, all I see is a seal that fits around the thermostat.

Is there still the diamond shaped gasket under the housing?

What will I find after I pull off the housing?

Thanks in advance.

[Bio248]

the o-ring on the thermostat IS the gasket.

[TheOtherNick]

97 and 98s had a gasket under the housing also, most do not need it.

[Bio248]

they dont sell that gasket anymore for the 97/98s. i tried to find it.

mine sealed fine without it.

[TheOtherNick]

Sean just got one like 2 months ago.

[Bio248]

hm, weird. no one could get it for me around here.

either way its not necessary.

[TheOtherNick]

Yeah his sealed up with just the o ring also.

[Madness]

Thanks guys, the last thermostat I changed was on a 1980 GMC K-25 w/small block 400. In high school, we flipped the air cleaner lid for a little extra zoooooooooooom. That was almost 20 yrs ago.

Thanks again!

[brandonl2000]

Yeah. There's the rubber o-ring around the gasket, which will seal it up fine. But they do still make the paper gasket for the housing, which if you want to be anal about you can get for your own security of knowing it won't leak.

[MoarkatsINmuhtrailer]

yeah nick (bio) we sell the diamond gasket at advance. you shouldnt need it, and to let you know that it will seal for sure. my housing is only held on by one bolt and the oring seal

[brandonl2000]

y u no have two bolts bro?

[MoarkatsINmuhtrailer]

i took em out to change it when the uim and lim gaskets went out. both bolts came out no problem...one wouldnt go back in straight at all and its completely sealed so i dont care

[rynoman03]

Ya sometimes they are b to get back in.

[MoarkatsINmuhtrailer]

thing is i had nothing in the way to get the extension around. all wires were out of the way. so i just said eff it.

[CrazyGuy03]

I always used a small amount of Right Stuff Why chance it

Same stuff I use for all gaskets , intercooler, supercharger, intercooler core plates etc..

Should pick a can up. Can come in handy

[brandonl2000]

i see. on my GT, somehow i managed to strip/cross thread both of the bolts. so i had to re-tap the bolts holes in the LIM. talkin about a pain in the ass. and the thing was i remember myself making sure to get them going correctly before i put a ratchet on em.

needless to say, when i do tstat on the gtp, i put the bolts all the way in with my fingers first.

[CrazyGuy03]

Holy f-ing URL batman

[MoarkatsINmuhtrailer]

lol

[BillBoost37]

The paper gasket was originally used up until 2000 on the motor. Then w/o warning the gasket disappeared. I'm not sure if the surface of the LIM was brought down to accomodate the rubber seal making more contact etc...but the rubber seal "typically" seals up. I always use a little copper rtv on the t stat housing to ensure it seals w/o worrying about the gasket.

If you can't find the paper seal, take a close look a the notes, there is another replacement part number that works for it.

[Fritcr]

Funny, I just got on here to see if anyone can help me with this. I just put a thermostat in my gt and it will not seal. The guy at O Riley's said it don't need a gasket just o ring so I changed it out and it would not seal up so I went back and he found a gasket. Took it apart last night and put the gasket and o ring and it still not SEAL. Any ideas? I cross threaded the longer outer bolt too but got it back in straight and it tightned up good. I don't know what is going on. It was not heating up right. It does heat up good not but also leaks.