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kbtVR6

Corrosion at Thermostat housing face

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I don't know if anybody else has encountered this issue of if you can make it out on the following photo's, but just after I bought the car I noticed a small water leak and couldn't trace it's source (it was very small) While checking the thermostat housing I noticed that there was significant corrosion pitting on the sealing face of the cylinder head, up to about 1mm in places.

Also the thermostat housing had obviously been off at some point and the sealing face had been filled up with silicone sealant to try and overcome this problem (not by me you understand!)

The solution that has worked for me is to clean out the pitting and thoroughly degrease, and then fill with epoxy (although Devcon aluminium chemical metal would be ideal, just didn't have some to hand) and allow to harden. Then gradually pare back the high spots with a Stanley blade and finally lightly sand the whole area.

A new housing has been fitted with new seals as the old one was also damaged and split round the inner lip for the seal. All seems good with no sign of any leakage.

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Yeah that's quite bad but not unusual for a car of this age... probably due to incorrect coolant used at some point?

 

I'd carry on sanding to skim the surface more - luckily you don't have to be that careful with metal fillings at that point.

 

Other option is to skim it carefully with silicon and let that go off and then use a new housing with the O ring seal as normal.

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Yes, I think the coolant was to blame, it was horrible brown colour with loads of sludge around. That was the reason I though I'd better have a look around the system. Have flushed through everywhere thoroughly. Replacing it with G12++. I have also fitted a new radiator today as the bottom tube was severely ovalated, although overall in good condition this car is a keeper and has to be 100% reliable (well as far as a '95 car can be expected!) Everything else on the car has been replaced pretty much, just engine needed seeing to as previous owner ran out of enthusiasm after 4 years rebuild and new house/wife etc and £10k spent. Might put a build thread and photo's up sometime, should be complete this week..........

Already sanded down a little further and checked perfectly flat, and did put a smearing of silicone on the face with all new seals and housing. Ran fine with no sign of leaks now

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