Corrosion of the thermostat cover

Hi all

I have experienced considerable corrosion on the thermostat housing cover. The cover/housing appears to be aluminium and is been eaten away. I use a standard anti freeze and the water is very clean as is the radiator.
Have members had similar problems and if so what is the cause and remedy?

Thanks

Corolanty said:

Hi all

I have experienced considerable corrosion on the thermostat housing cover. The cover/housing appears to be aluminium and is been eaten away. I use a standard anti freeze and the water is very clean as is the radiator.
Have members had similar problems and if so what is the cause and remedy?

Thanks

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Welcome to The Forum.

This is common--both my BN2 and BJ8 have some--and is due to 'galvanic corrosion' (the same chemical phenomenon that causes shroud flanges to corrode--electrons like to move between the metals, abetted by moisture). Anti-freeze doesn't really help, as it's usually mixed with water and the paper gasket usually used between the block and the housing gets moist and doesn't prevent the movement of electrons. A silicone or other sealant applied to the gasket or in lieu of the gasket might help, but I've not tried this (I usually use Permatex 'Aviation Form-A-Gasket' on these, and it seems to help a little, but can be a bear to remove). About all you can do is replace the housing; a new one should last a couple decades.

https://en.wikipedia.org/wiki/Galvanic_corrosion

We can always rely on Bob Aka Bill Nyne The Science Guy to come up with a super scientific explanation for the issue .
Basically its cheap crappy metal and eventually its going to fail , buy a replacement .

I've owned my car for 55 years and had to replace it twice due to corrosion. Just one of those parts that are meant to be replaced like the gas tank. Eventually, corrosion will do them in.

Healey Nut said:

We can always rely on Bob Aka Bill Nyne The Science Guy to come up with a super scientific explanation for the issue .
Basically its cheap crappy metal and eventually its going to fail , buy a replacement .

Click to expand...

I'm only as smart as Wikipedia

Thanks Guys.

Healey Nut said:

We can always rely on Bob Aka Bill Nyne The Science Guy to come up with a super scientific explanation for the issue .
Basically its cheap crappy metal and eventually its going to fail , buy a replacement .

Click to expand...

With galvanic corrosion, some metal has to corrode. By having the thermostat housing, made of cheap metal, corrode rather than the head and block, it saves having to buy new heads and blocks, which are more expensive.

New ones from Moss are < $20

John Turney said:

With galvanic corrosion, some metal has to corrode. By having the thermostat housing, made of cheap metal, corrode rather than the head and block, it saves having to buy new heads and blocks, which are more expensive.

Click to expand...

Healeys had sacrificial anodes before they became cool!