T-Stat Install

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Founding Member
Sep 18, 2000
FL,89 LX 5.0
simple install : drain your coolant , remove upper radiator hose and upper water pump hose , remove two bolts that hold on thermostat housing - these can be tricky but be patient and you can get an open end wrench in there . It would be easier to loosen your distributor and turn it towards the passenger side as the TFI module will be in your way . remove the housing , remove the thermostat , scrape all the old gasket material from both surfaces , install the new stat and gasket using about a 1/8 bead of rtv on the gasket (allow the rtv to cure for about 3-4 min before installing) . Remember the spring end of the stat faces the intake . put all your hoses back and top off with coolant then start it up and check for leaks .

I used a 180* stat from NAPA , stainless steel - nice piece .

Good Luck


Mar 31, 2005
Boston, MA
Mr. Gasket makes a good stat. No matter what kind of t-stat you get, I would test it in a pot of boiling water to make sure it opens. Occasionally you find a few that won't open.

Just drain the coolant below the level of the t-stat, which you can find by following the upper radiator hose to where it connects to the t-stat housing. Remove those two bolts (1/2" i think) and pull out the t-stat housing. A little coolant will come out, which is normal. Clean off both surfaces real well (I use simple green on a rag and some razor blades, but easy because its all aluminum). Get a new gasket, fel-pro works well. I use a thin bead of RTV also just for reinsurance.

Oh btw, the spring on the thermostat goes into the intake. :nice:


"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
Another Mr Gasket vote. A local speed shop should have one for about 10 bucks. Summit is (or used to be) just under 8 bucks (if you happen to be ordering).

Good luck.