Hi everyone, my partners car is leaking from the thermostat housing. 

 

It had a leaking thermostat last year so I fitted a new one, it was fine for a couple months then the new one started leaking. 

 

I noticed when I took it off that the bolts are offset to the bottom of the housing so it puts more pressure on the bottom forcing the top away from the block.

 

So I took it off and checked the seals they were fine, so I put some sealant around it and refitted. After a couple months it started leaking again, so I took it off and put loads of sealant on it but now it is leaking again.

 

Is the thermostat housing faulty or is the mating face warped or the housing? I think having a plastic housing is a stupid design anyway so I think it might be the plastic has warped. I wouldn't have thought the effect of the offset bolts would occur so quickly.

 

Does anyone have any ideas about what to do or wether there is a metal alternative?

 

Cheers

Edited 1 April, 20179 yr by retro

Buy another housing, they're not expensive, it happens.

It shouldn't need any sealant on it at all, it seals to the head with an O-ring and that's all it needs. If it needs sealant there's something wrong with it.

17 hours ago, TMB said:

It shouldn't need any sealant on it at all, it seals to the head with an O-ring and that's all it needs. If it needs sealant there's something wrong with it.

That's what I thought. I have done some digging and found a guide on here and the guy said he fitted a 3.5mm thick o-ring rather than the 3mm supplied one.