Melting thermostat housing...

[rockthebus]

Hi Chaps
Next on the list is sorting the leaking thermostat housing...

I replaced the housing with a brickwerks one last year, and all was fine (well after getting the bolts out which were corroded into the old housing!).
Recently, I fitted as stainless exhaust (VW Speedshop), and all was fine...

Well I noticed that it was leaking from the Temp II sensor, so replaced the O ring, and its still leaking. Then i noticed that the housing appears to be melting where the housing meets the metal heat shield. My guess is that the stainless manifild if giving off more heat and melting it?

So what are my options?

Do I need to replace it and also fit a better heat shield?
Wrap the exhaust?
Is it possible to fit the synchro one which I believe is alloy?

Thanks in advance

[rockthebus]

Could I adapt a synchro one? What are the differences?

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[itchyfeet]

Did you buy the budget housing?
if so I found the sensor aperture was a full 1mm oversize, I sent it back and bought the VW housing.

Melting of the housing sounds strange, I wonder if you have a cylinder running lean, happened to somebody the other day, when a stainless exhaust was fitted they ran it at 2500rpm for 20 mins and one pipe was red hot? Suggestion was a duff injector.

https://club8090.co.uk/forum/viewtopic.p ... n#p8134263" onclick="window.open(this.href);return false;

Another suggestion is water dripping making steam which is degrading the plastic.

Lots of people have stainless exhausts with standard therm housings and no problems

[rockthebus]

Thanks Itchyfeet that's good to know. I bought it from brickwerks. Where would you get the vw one which you mention?
Thanks

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[itchyfeet]

genuine VW
https://www.brickwerks.co.uk/thermostat ... etrol.html" onclick="window.open(this.href);return false;

Budget one I bought with sensor holes over size...to be fair they said they sold loads with no complaints but If you buy the VW one then please compare and report it if oversize, it may have just been a bad batch, mine was purchased this time last year.
https://www.brickwerks.co.uk/thermostat ... udget.html" onclick="window.open(this.href);return false;

[ghost123uk]

Just to confirm, I used a VW Speed shop exhaust (on my "other van") with the original stat housing and never had any problems.

[rockthebus]

Mmmm just checked my order history and it was a genuine one I fitted ordered from BW
It was fine until I fitted the exhaust. Not cheap either to see if it goes again. Thanks for your replies. Much appreciated

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[Smiffo]

Just to confirm, I used a VW Speed shop exhaust (on my "other van") with the original stat housing and never had any problems.

I now have a stainless exhaust fitted with a budget housing from BW. No issues either.
I haven't had it all long, but it seems OK after taking a little peek and there are no leaks either.

[itchyfeet]

Mmmm just checked my order history and it was a genuine one I fitted ordered from BW
It was fine until I fitted the exhaust. Not cheap either to see if it goes again. Thanks for your replies. Much appreciated

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I wonder if your pressure cap is duff and the system is not venting, if so it would leak at the weakest point, best check it, it should quack when you blow down it.

I take it you replaced o rings on sensors with correct type?

[rockthebus]

Thanks again to you all

I'm just about to order a neew housing and fitting kit.

It was 2 years ago when I replaced it all, including the fitting kit, in which all O'rings etc were fit for purpose at that time.

You've got me thinking about the Darlek cap though, as recently I've had to fit a waterpump, loads of hose etc due to seeps etc. Maybe thats the culprit!

I'm short on time, and looking after my Todler tonight, so I'll order a cap as well. It'll always be good as a spare.

Love this forum - cheers

[ghost123uk]

I noticed that the housing appears to be melting where the housing meets the metal heat shield.

Melting of the housing sounds strange, I wonder if you have a cylinder running lean, happened to somebody the other day, when a stainless exhaust was fitted they ran it at 2500rpm for 20 mins and one pipe was red hot?

Reading back on this, I am thinking it may well be that ^^^
Or perhaps the heat shield is not doing it's job by being assembled incorrectly when the new exhaust was fitted (got a pic Paul?)

[itchyfeet]

(got a pic Paul?)

only heat shield on my DG is the tiny one on the stat housing, can't see how it could be incorrectly assembled, it should not need to be removed.

[silverbullet]

Heat sheild is held onto the stat housing by a couple of small self tappers.
Stainless exhausts are generally thinner than the mild steel equivalent (no corrosion allowance and makes them easier to form)
I have personally seen the speedshop headers glowing cherry red at the first bend after a run, but only in low light.
No harm in wrapping them, a friend of mine does the same on his race car (to stop the floor paint burning) and he found some horsepower for free.
But you ought to find out if one cylinder is going lean. Is it a carb or injection engine?

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[itchyfeet]

Carb has the brake vac take off by no3 cylinder, if that leaks can be lean, not sure where injection takes it's vac from?

[silverbullet]

Servo vac on plenum for efi

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