Thermostat gasket question***Split from fuel elbow thread***

[jawn101]

New problem: now that the engine is running, the thermostat housing is leaking! Arggghhhh. Got the new thermostat and o-ring from Hervey in a new water pump kit so I'll ask him about it tomorrow. It looked like the o-ring was meant to fit on the wrong side of the thermostat. Anyone else had this problem?

[content22207]

Thermostat goes *INSIDE* the seal -- quite different from a traditional thermostat gasket.

Bill Robertson
#5939

[jmettee]

New problem: now that the engine is running, the thermostat housing is leaking! Arggghhhh. Got the new thermostat and o-ring from Hervey in a new water pump kit so I'll ask him about it tomorrow. It looked like the o-ring was meant to fit on the wrong side of the thermostat. Anyone else had this problem?

Yep.I was helping someone with their car & the o-ring it came with (not sure who they got it from) appeared smaller & was different than stock. It leaked when we pressure tested the system, so we just used the seal from the old thermostat & it worked fine.

[jawn101]

Anyone know if these two thermostat seals are the same or compatible?

DMCH:
https://www.delorean.com/store/p-6246--gasket-thermostat.aspx

Napa:
https://www.napaonline.com/Catalog/CatalogItemDetail.aspx?A=THM1092_0067127472&An=599001+101981+50076+2076003

[Ashyukun]

I had a similar issue crop up with the thermostat I picked up from Hervey a way back but hadn't gotten around to trying to install until recently- the seal/o-ring included was the 'traditional' o-ring type that only sat on one side of the thermostat vs. the 'c-channel' type that was on the old one. Unfortunately, I wasn't able to get the old one off without damaging it (it was pretty deteriorated), so I just ordered a new one from DMC-MW.

Was curious if it would work with just the o-ring- looks like my assumption that it wouldn't was correct...

[jawn101]

I had a similar issue crop up with the thermostat I picked up from Hervey a way back but hadn't gotten around to trying to install until recently- the seal/o-ring included was the 'traditional' o-ring type that only sat on one side of the thermostat vs. the 'c-channel' type that was on the old one. Unfortunately, I wasn't able to get the old one off without damaging it (it was pretty deteriorated), so I just ordered a new one from DMC-MW.

Was curious if it would work with just the o-ring- looks like my assumption that it wouldn't was correct...

Looks like it. It really felt/looked to me when I put the ring in that it was creating a positive enough seal on the thermostat, but that it was just on the wrong side. I operated on the assumption that it didn't matter which side the seal was on as long as the thermostat housing was kept separate from the water pump unless the thermostat opened. I guess I was wrong as well. My old thermostat seal was also really deteriorated so that was a non-option.

[jawn101]

Success! On suggestion from Clint again, I picked up a thermostat housing gasket from an 81 Volvo GLE at Napa. It fit perfectly and sealed the housing completely. The motor is running great now!

But, my luck... some coolant did end up in my newly cleaned and painted valley. Will it eventually evaporate/burn off? Or do I need to take it all apart to clean again...

Now on to my next challenge... the rear fascia isn't fitting back on properly. Sigh.

[DMCMW Dave]

Was curious if it would work with just the o-ring- looks like my assumption that it wouldn't was correct...

It won't. An o-ring alone will not seal that joint. The original seal wraps around the edge of the thermostat, it doesn't just sit on it.