Hey guys -

I replaced my thermostat when I did my timing chain a few months ago and I recently noticed a lot of crusted up coolant around my thermostat housing. The housing is torqued properly to 13 ft/lbs, but I'm still getting this leak. When I replaced the thermostat, the new one did not come with any sort of gasket. The old one did have a little o-ring type thing that went around the thermostat. I reused that since I had no other alternative in that moment. Is this just a matter of getting a new o-ring like this one?

Or is there an actual gasket for the housing?

Thanks!

 

That o-ring is it. Maybe the old one had gone stiff.

 

Yeah I remember it felt like a potato chip when I pulled it off. Ok - new one it is! There's no RTV or anything else that's supposed to go there, right?

 

If everything is pretty and fresh with no corrosion, the o-ring is all that is supposed to be there. However, typically the surface it seals against is a bit crusty. I always use a thin ring of RTV just outboard of the o-ring to prevent leaks.

 

The same thing happened to me after putting a new thermostat in, got it as clean as I could but kept leaking with just the o ring. A thin application of RTV fixed the issue, just like arlinsday1992 says.

 

So far I've been lucky. When I change the thermostat, I clean the mating surfaces to good clean metal, since there's always corrosion/crusted coolant on the lower one, and put a new gasket on. I haven't had any leaks. Yet
Usually about once every 2 years, I replace the t-stat, and it's gasket. I keep the old ones, in case of unexpected problems. I throw out the ones I was keeping before, so my spares are only 1 or 2 years old. Belts, hoses plugs, wires, everything.

Have fun!
Pat☺