DaveOx

Did the huge timing belt job last month on my '01 2.7T and replaced everything (TB, tensioner, idlers, thermostat, WP, serp and tensioner, etc. all from Blaufergnugen). Now I have a little coolant leak after she cools off. It is manifesting out from under the alternator at the oil pan. Only leaks to a small puddle and then stops, presumably after pressure is equalized?

I saw Kingfishgrapejam's writeup about the WP leaking, but my leak is definitely coming down from the thermostat area. If it was the WP or the freeze plug it would come down on the dipstick side for sure, which is totally dry. I can snake a mirror in there and see the thermostat housing is a little wet and I can see the passenger side of the crank cover is pink at the gasket.

Has anyone dealt with a leaking thermostat housing? Does the plastic ever crack? Will the O-ring eventually seal up? Should I use Alumaseal (I have my Nomex on for that flame war...).

Thanks all.

samm

All I can say is I had the exact same thing happen after I did a T.B. could not find the source, took it to a friend who owns an Audi shop and he thought it was left over from spilled coolant from the T.B. job. I thought B.S. there is a leak for sure. A few days later the leak stopped and has been dry ever since (3mo) maybe he was right?

Zuffenhausen951

YES - that plastic thermostat housing does crack...and does so catastrophically. Here is mine, with a nine-inch gash:



This happened to me at the absolute worst time....climbing up a 5500ft mountain! The car was completely empty of coolant, by the time I shut knocking and pinging car off and towed it straight to the Audi dealer.

DaveOx

Wow, that's nasty. My leak was definitely the water pump and I returned it to Blau for a warranty replacement. No problem since. I also have a 2000 S4 and that motor uses an aluminum version of that thermostat part - I highly recommend you replace with that.

=Dave

Kristopher

grave digger!
lol

well, I feel it's probably not a bad idea to post this here also.
I had a weeping t-stat housing also. Turned out to be the VEMO t-stat! it's just mm taller than the OEM one and puts too much pressure on the backside of the cover.

I found 3 cases of this aside from mine

my other post - https://www.audiworld.com/forums/sho...2#post24326592

Zuffenhausen951

NEVER use non-OEM thermostats. Period.

Cooch

Just found a crack in mine to 2012 Q7 $500 for a replacement 1.5 hrs work so not to bad really.

PaperToast

dude, what was the point of your post?
super old thread (6 years), and if your talking about a q7, wrong section