Boneman

About a year ago I replaced the thermostat housing on my 05. Interestingly enough... at that time the car had 146K miles on it. I'm not sure if it was the original housing as I bought the car with 58K miles so it's anyone's guess. I did not opt for the aluminum unit but purchased an "updated design" plastic piece from Rock Auto. Installed it and all was good.

December '14 pursuant to having very little heat coming out of the registers, I presumed the thermostat had failed... so I procured and installed a new one.

About three weeks ago... I notice the damn thing leaking... so I checked the three bolts for the 'stat itself.... one was not nearly as tight as I thought it should be so... I fixed that. The leak got worse.

OK... fine, I procure and install a new thermostat gasket (fel-pro this time) and was good to go. For... about a week. Coolant once again... leaking from around the thermostat gasket.

So now I'm wondering... is it possible the damn plastic unit failed in just under a year? I'm going to take a good look at it again tomorrow to see if I can spot exactly what's leaking... but there is coolant on top of the thermostat housing so I presume it's leaking around the damn thermostat gasket again.

And WTF is up with these damn O-rings.... I remember using treated paper gaskets and permatex and never having a problem... but then... not sure if that would work at all on plastic parts either....

Any insights.... would be most welcome and imminently appreciated.

JimC

It's possible that the housing failed again. I know people who replaced it 3 times in 60,000 miles. There isn't anything that you can do that will tell you how long one will last. On my 2006 the original one lasted 199,881 miles - and let loose just as I was staging the car. No warning, no low coolant or coolant smell. Just a geyser went off suddenly.

07 Stang

Why not try the aluminum one?

Boneman

Thanks for the feedback. I'm going to give it an extremely close look today to see if I'm just missing something subtle. I am leaning toward getting the aluminum replacement I just figured last year... why spend that much on a car with this kind of mileage when I could get another 100K miles out of a plastic unit.

I will be keeping the car for a while and that it gets too farking hot here in FL to play around with something that... well... at this moment, I do not have complete confidence in. I'll probably go aluminum if in fact I conclude the Dorman replacement is failing.

JJHoover

I have 230k miles on the original one

Boneman

Kudos JJHoover. I was pretty impressed that MY original went to 147K. The replacement? Not hardly so much....

Apparently, when they're GOOD... they're GOOD. Thing is.... you just don't know until they go bad... then you're in the same boat that I'm in right now.

DONE playing. The aluminum unit is on it's way. Yeah... expensive.... but so are roasted heads and stuff like that I don't care to ponder....

66and06stangs

I have never had a problem and was shocked when I jumped on this forum and read about it. I got an aluminum housing in the box ready for the Florida summer.... just in case. I figure why fix it if it isn't broken.

Boneman

Agreed there. Well... why fix if it aint broken IS for the most part valid, IF you gotta fix it, go the extra mile with the aluminum unit. I'm regretting not doing that last year when my plastic unit failed at 147K miles.

Apparently, the plastic units are still very hit or miss.

66and06stangs

Yes, and after all the threads I've seen I didn't waste any time getting an aluminum housing...

Boneman

Yep. Kinda makes me wonder how dealerships and other repair facilities are handling the issue.