hey guys, anyways, when i installed my paxton supercharger on my 91trans am (350 tpi) i decided to put a 160degree thermostat in it as well. when i initially put it in, i just used the recomended gasket without any silicon. well, shortly thereafter (about three days) the t-stat housing started leaking again so i pulled it off and noticed that i had blown part of the gasket out. so i scrapped the mating surfaces and used just "right stuff" silicon without any gasket, along with drilling two small holes on either side of the flange of the t-stat. well, its been about 200miles, and it looks as though it's leaking yet again, so i guess my question is WHAT AM I DOING WRONG HERE?

can anyone hepl me out. thanks guys

mike

 

Gasket plus RTV silicone?
POZ

 

Have you checked to make sure your radiator cap is functioning correctley, it may be building more pressure than the system can take, just a suggestion. Also hope you have not blown a head gasket and are putting pressure in the system that way. Did you have any overheating problems? But like thepoz89 said baring any of the forementioned problems you my just need to use a gasket and a thin layer of silicone, or maybe get yourself a better housing with an o-ring. Hope you get it worked out, bad news having a nice turbo car set around.

 

GM made a poor material/design choice with our thermostat housings. they made them out of cheap pot aluminum. because of this, they warp with normal temps..

if you put a straight edge across the bottom of the housing, im positive you'll find it to be slightly warped.
on TBI cars, i reccomend replacing it with a cast iron truck one, that will never warp.. but since TPI cars require that unique extended neck, i dont know if they make another one..

you cant try sanding/filing it flat.. ive had some success with doing that in the past, but its hit and miss.. your best bet is to replace it.

 

i would use the gasket, i use just the regular black rtv with a gasket, havent had a problem. they say when you change the thermostat, let alone just opening it back up that you are suppose to replace the gasket again

 

Autozone sells a thick black plastic gasket with a wide red rubber ring inside. I've been using those on everything, without silicone, and I've not had one leak yet. I've even reused them a time or two.

 

cool, thanks buddies.

no it hasn't been overheating, and the radiator cap could be a possability. but i'll see if it's still leaking, if so, i'll go get one of those plastic gaskets you guys were talking about. so are all of chevy's sbc stat housings the same, i mean, i know ours are extended, but it's ok because in order to put my charger on, i had to cut it down 2" (don't ask lol) so mabye i could do that if all else fails.


how else would i know if my head gasket is blown

 

milky color in your oil if the head gasket is leaking

 

LOTS of smoke out of the exhaust... Exhaust would smell like coolant.

 

ok, well it only seems to be leaking periodically because i went to get my hair cut today, and not to mention someone test drove it yesterday, and still, no coolant to be found. so i dunno, i'll see where this goes lol.

thanks for all youre guy'zes help, you guys rock a$$!

 

POZ