So i replaced my thermostat and filled the car with coolant and I noticed that I had a pretty big leak from the thermostat housing. I replaced the thermostat housing gasket and I noticed now it started dripping slowly. I ordered a new o ring for the water pipe that the housing sits on top of. I was just wondering if the thermostat housing gasket also needed to have a sealant applied on both sides of the gasket or if you just install the gasket itself as is. I looked through the factory service manual and couldnt find anything on it. I think im going to put some thread sealant on the 4 bolts themselves just to be sure its not leaking from the bolts.

 

I literally just did a full service on my cooling system last week. New radiator, thermostat, thermostat housing gasket, radiator hoses, heater hoses, turbo coolant hoses, etc. I applied the import grey rtv in a very thin coat on both sides of the gasket in question when I did it and let it sit for 10 minutes then installed it and it hasn't leaked at all. My advice would be to use the import rtv.

 

Alright, I have some gray rtv silicone that I used on my valve cover gasket so I'll use some of that once my gaskets come in.

 

rtv is your friend

 

+1 on the rtv and also make sure the thermostat is seating properly in the housing mine kept sliding out and between the gasket. Took 3 tries until my dumb *** realized it kept falling down between the gasket at the bottom.

 

hang on…

firstly i would like to ask why you decided on a thermostat change?

(as i am looking to do this task too.)

secondly, i thought the stock thermostat has a rubber ring around it and does not require a gasket?

hmmm

 

whats an RTV?

 

Ill second this, I just did my thermostat last week, NO RTV used, opened housing, pulled the t-stat out, popped new one in, and 3 bolts back in and boom done! no leaks.
I dont know what this RTV talk is.

 

The rtv talk has nothing to do with the thermostat oring first of all. Reread the first post again, except pay attention this time lol. He never said his thermostat was leaking. We are talking about his thermostat housing. It bolts to the cylinder head with 4 bolts and is what the thermostat sits inside of.

 

This. The thermostat was replaced just as preventative maintenance along with a lot of other stuff since I did a lot of maintenance before the nicer weather comes around.

I replaced my timing belt and wanted to do a compression test so I was preping everything and refilled my car with coolant. That's when noticed it was leaking from the thermostat housing. My car has been in storage because of the winter so it hasn't been started in about 7 months so I'm assuming the gaskets just dried out.

 

Jw but did you reinstall the housing with the water pipe bolted in tight or with it loose? Just wondering. I did it with the pipe tight and it made getting it to seat on the pipes oring a pain in the *** but I was able to get it on with a little muscle.

 

Everything was tight. All I removed other than the thermostat was the 4 12mm bolts holding the housing to the head and the 1 10mm bolt holding the housing to the water pipe.

 

Sorry, Disregard my post.

 

Well, All this talk of RTV and no one cares to explain.


<---- The thermostat looks like it has an o-ring on it already???


<---- im assuming the thermostat sits in what Mitsubishi calls, a "Water Neck".. located on the upper side of the coolant hose, near the battery and upper intercooler pipe.



now, i dunno what the hell this thing is; that is called "Thermostat housing" ; (unless its some other type of "thermostat")



and its associated gasket;



any ideas?

 

The reason I asked was I also did it with the water pipe still attached and the first time I tried to install the gasket and housing its such a tight fit there up against the head, that's when I pulled it back out and noticed the bottom* of the gasket got pushed up a little bit and would have leaked. I actuslly used the rtv at first just to hold the gasket in place while I was installing the housing so it wouldn't move around but I'm pretty sure it helped with sealing it up too. I'm curious when you pull it back off if the bottom of the gasket ends up all deformed and smashed upward. Let me know plz.