Thermostat housing leak

[Beej '86 325es]

Does anyone have the #7 gasket installed? Realoem does not list the P/N and I can't find the part anywhere. It's leaking there, so I'm assuming I need to have it.



Thanks

[BigD]

Here you go:



My answer is no I don't. My aluminum cover came with rubber gaskets pressed in around both openings. EDIT: No that's a lie, it's only around the return outlet. The other side should be sealed by the T stat... but mine doesn't leak. If you have #6 and #8 it shouldn't leak...

[FredK]

No. I don't have that gasket installed on any of my engines.

Should you want to install it, it is PN 11531748047. It came on early E34s and E36s that had an aluminum thermostat housing from the factory (not that Ronak cast POS). Early NV cars came with an aluminum thermostat housing, then BMW shifted to a plastic thermostat housing.

I ran into this problem 4 years ago when I replaced the stock plastic thermostat housing on my E36 328. I installed the Ronak aluminum t-stat housing dry, with just the orange gasket. This resulted in a small drip. Soooo, I pulled it and ran a thin layer of Hylomar around the housing and reinstalled it. No leaks for the past 40K miles.

[Beej '86 325es]

I ran into this problem 4 years ago when I replaced the stock plastic thermostat housing on my E36 328. I installed the Ronak aluminum t-stat housing dry, with just the orange gasket. This resulted in a small drip. Soooo, I pulled it and ran a thin layer of Hylomar around the housing and reinstalled it. No leaks for the past 40K miles.

I may not have gotten a good seal with the sealant I put on there. I'll give it another shot.

Thanks for your help guys.

[static]

Fred, why is ronak POS? thats what i have and it gets the job done

I used permatex gasket in a tube to seal around the perimeter. Worked good, no leaks
I am thinking you don't even really need those gaskets that much (if you don't already have them) as long as you seal the perimeter well - if some coolant leaks from inlet to outlet internally, IMO the rate of this internal leak would be negligent to affect anything.

[Mr.SWISS]

when I swapped out my NV M50 one it had a plastic and just the rubber O ring on the t stat, and the orange gasket for the return. Installed dry with no issues. I read somewhere that the #7 gasket you pointed out was only on early 5er's, but you can "upgrade" to the later style.

[FredK]

Fred, why is ronak POS? thats what i have and it gets the job done

Yes, it gets the job done.

Their quality control is terrible, assuming they HAVE QC.

I have received two brand new ones in terrible shape. One had a large void right on the flange that would have caused a leak immediately upon installation. The other had a terrible looking mating face with gouges all over it and a void in the hose fitting, where a tiny crack had started. With sufficient thermal / pressure cycling the crack probably would have grown. All of them had lots of casting flash everywhere.

One of the things that can contribute to poor sealing is the built up crud on the head's mating surface, but if I recall correctly, Beej has a brand new remanufactured head so this shouldn't be an issue.

[Beej '86 325es]

Thanks guys, put more sealant on it and no more leaks!

Just spent $2200 on the other bimmer fixing a coolant / overheating issue...I don't want to see a jug of coolant ever again.

[Beej '86 325es]

Mother f*er. The leak is back. I just got the E30 started again tonight for the first time in months due to a starting issue too.

I used Curil-T sealing compound, and I used a generous amount. Everything on the bottle says it is the absolute perfect stuff to use for this situation, but yet it still leaks. I'm running the two gaskets (#6 and #8 ) as shown above.

What do you guys use?

thnx

[FredK]

Wow, that is just bad luck. The Curil-T should be fine as a sealant. I've seen cheap Permatex O2 sensor-safe silicone work fine. Are you dressing gaskets 6 and 8 with the sealant? I'd try doing that if all you did was to dress the perimeter of the thermostat housing.

[matt]

You shouldn't even need any sealant there. Don't take this the wrong way, but are you tightening the bolts all the way? Are you being a cheapskate and not replacing the O-rings?

[10Toes]

Pelical parts #11-53-1-748-047-M17

Under Thermostat Housing Gaskets

http://www.pelicanparts.com/bmw/catalog/shopcart/BE34/POR_BE34_WATpmp_pg4.htm

[FredK]

You shouldn't even need any sealant there.

Yes, you "shouldn't" need any sealant. But, these are cast aluminum parts which likely have a wider range of dimensional tolerances than BMWs original molded plastic housing. I wonder if there are even any outgoing QA checks.

I guess I'm just an aluminum thermostat housing hater.

[Beej '86 325es]

Yes, you "shouldn't" need any sealant. But, these are cast aluminum parts which likely have a wider range of dimensional tolerances than BMWs original molded plastic housing. I wonder if there are even any outgoing QA checks.

I guess I'm just an aluminum thermostat housing hater.

Ha - I'm going to take the housing off again tonight and see if it's got some pitting in the mating surface of the housing or something.

Matt - yeah, almost everything on the motor is brand new. I'll probably be contacting you in a couple of months about some custom tuning once I get the wideband O2 operating. I've got a TMS chip for the cams and usual bolt ons, but that only gets me part way there with the modified internals.

Anyone else using that gasket that nwvb bmw posted?

[dude8383]

you know its funny you made this thread...when i built my motor i actually using both gaskets because i wasn't sure...

i also used form-a-gasket on it just to be on the safe side and i had zero leaks.

just yesterday i switched to 80 degree t-stat and just used the rubber gasket and so far no leaks :)