or thermostat housing or whatever its called. I overtourqed the old one and don't want to do it again. should i be using rtv silicone or something, I couldn't get the old one to seal without leaking under load and that is what led to the over tourqe.

 

Yea get a new housing, gasket and rtv. I recommend the blue stuff, if it's available.

 

WILCO thanks!

 

This page is on installing an intake..but the technique is exactly the same. Be sure and use a gasket.

http://www.mustangsteve.com/intake.html

 

Check to see if the recess for the thermostat is on the intake manifold or the water outlet. The gasket should go on the opposite side of the recess over the thermostat.
Jim

 

i had this problem on the thermostat housing on another car. make sure the area where it seals is very clean. you can take sand paper too it and clean it up. it worked like a charm for me

 

great thanks for the tips

 

Another good tip don't buy the crome housing they are junk and will leak. Ask me how i know. BTDT

 

Yup, chrome don't get ya home.

 

I've used chrome. I've used cast iron. I've had problems with both. I've cracked two cast iron, had three leak. I've had 2 chrome ones leak and one almost completely disintegrate and gunk up my cooling system. The leaks and cracks were all caused by my own lack of being thorough (in two leak cases, fixing a car by braille on the side of the road isn't always the best situation, but when my thermostat failed, that method got me home without blowing head gaskets).

The key is making sure you put the thermostat in the housing and making sure it stays put in the race when you bolt the housing to the intake. It it's off, you could crack a cast iron one and cause a leak around either cast iron or chrome. Also, even if you're using chrome, put the rubber O-ring in if it makes you feel good, but definitely use a gasket and sealant of your choice. Them O-rings don't last long with or without silicone. I had one seal for a while, but using the gasket plus silicone was fail-proof.

I use chrome now because it looks better in my engine compartment, but I replace it every year or two to avoid another disintegration.