Really dumb question

[JeffW]

Leaking thermostat cover despite what I do, so I opened it up and note that the bottom bolt goes right into the chamber...meaning the coolant just winds its was right out the bolt.

I assume at one point this was not the case and that the bolt hole was NOT just a hole, meaning the end has corroded away?

[Lingen]

Jeff.
I think it is unlikely that it has corroded away, but more likely that someone has put an over long bolt in and blown the end out. Some silicone sealer on the bolt threads should make it watertight.
I hope you won't mind me suggesting that you also check that the thermostat is seated correctly when you replace the cover. Being vertical it is very easy for it to drop down a bit, which will stop the gasket sealing properly.
Mike.

[JeffW]

Thanks Mike, I wondered if that was also a possibility.

I have tried everything to stop it leaking (PTFE tape, silicone, etc) but it will not torque properly as the gasket inevitably crushes before it is anywhere near 15 lbs ft and it leaks without the engine running. Will try to find a used inlet manifold.

Will also ensure the thermostat is properly seated!


Thanks again

Jeff

[Phil S]

fit a helicoil easy fix

[flying farmer]

Make sure the thermostat housing isn't warped, they often bend through over tightening.
Easy job to flatten the face using a file or a sheet of wet and dry sandpaper on a flat surface.
If the water is coming up the thread, use a flat washer under the bolt head rather than a spring one as the sealant stands a better chance if it doesn't have to seal the gap in the washer if the water is still getting up the thread despite the sealant.

Neil

[JeffW]

Thanks all

flying farmer the housing was already cracked (which is what I though the problem was) and the new one is flat and not warped. I tried the flat washer and silicone but it still dripped.

I'll see what I can figure out.

Thanks
Jef

[JeffW]

Just wrapping up some old posts to ensure if anyone else has this problem they know how I solved it.

I ended up putting Araldite putty over the open hole to seal it off, along with belts-and=braces pipe sealant on the bolt. No leaks and the putty bonded to the housing perfectly.

Thanks

Jeff