Thermostat Replacement--gasket sealant or not?

[Kweisner]

Hi all,

Replacing the thermo on my '07 197TT with 5.7L MCX. Do I use liquid gasket sealer or not? I've had conflicting info on this and am looking for experienced perspectives. Many thanks in advance for your guidance.

[mikeg205]

I use a bit of sealant because I had some pitting on mating joints on my 1995

[jfw432]

Same here... Mine was pitted pretty bad. I tried a new gasket first and it leaked like crazy. I had to use a lot of sealant to make it seal up. I guess it depends on the condition of your manifolds.

[Kweisner]

Thank you guys. . .sealant it is!

[Chief]

Coat each side of the gasket with gasket sealer

[mikeg205]

this is how my monifolds looked for my t-stat after I cleaned it up

[Kweisner]

Again, thanks for the confirmation. I think my old gasket must have had a tiny leak as well. When I pulled the manifold, one of the two bolts came out with a lot of rust dust in the threads. Likewise, the threaded hole was full of fine rust dust (the hole on the right in the picture). So, the good news here is that I pulled it now--otherwise, the bolt may have eventually rusted beyond normal extraction. Lost of WD40 to displace the rust, and back together it goes!

[Gert]

*Bump*

five months ago, I removed my thermostat due to an never getting warm engine.

Finally got my new thermostat but I forgot where the old one was fitted? It can be mounted in the upper and the lower housing.

It is an MCX year 2004, no closed cooling.

Anyone please?

[JimN]

Originally Posted by Gert

*Bump*

five months ago, I removed my thermostat due to an never getting warm engine.

Finally got my new thermostat but I forgot where the old one was fitted? It can be mounted in the upper and the lower housing.

It is an MCX year 2004, no closed cooling.

Anyone please?

You're wasting a lot of gas and losing performance. These, like all other engines, need a thermostat to run the way they were designed. If an engine never gets warm, REPLACE the thermostat, don't remove it.

You need to mount it in the upper housing if it's a marinized engine OTHER than the LT-1.

[JimN]

Originally Posted by Kweisner

Thank you guys. . .sealant it is!

If you use a gasket, and there's no reason not to, coat the bottom, stick it in place and let it sit for about 1/2 hour. Then, put an even layer on the top, place the housing on (preferably with no hoses, to it sits evenly) and press it lightly into place. Thread the bolts in but don't tighten it. Let it sot for about 1/2 hour before tightening them fully and don't run it for a few hours. I had problems with my cars and trucks with leaking at the thermostat and doing it this way cured it.