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View Full Version : WTF coolant leak....only in cold temps!?



B72011
01-11-2014, 08:58 PM
So we are up at my girl's mom's place in the mtns. I get up this am to hit the mtn for some shredding (snowboarding.) what do I find ? A puddle of coolant...small drips from the low end of the underbody shield. Her mom comes out and says, oh yeah, I forgot to tell you there was some dripping where you were parked last wknd when you guys were here....I thought it was condensation ya know?
I look at the coolant res. it's way down of course. Weird I think, is it the cold? I just did the front brakes and saw nothing on my driveway or garage floor during or after the job. So i go shredding....pulling a groin muscle getting off the lift at the end of the day....figures. So heading back home after getting picked up, I head to the store and I get some distiller water, fill er up. I check for dripping prior to driving it home...its stopped dripping...why? warmer temps? I drive it home down the Mtns an hour later.Stopping halfway I see coolant at same level, no drips. Drive the rest of the way home park it, no drips ...same level. Go out there an hour and a half later, same deal. Wtf? Why is this thing loosing coolant when cold? But no loss of coolant or dripping when warmer. I looked deep in there and saw nothing, no apparent hose leaks, no t-stat seepage or leakage. It was dark on arrival so tomorrow AM I'm gonna pull off the under shield and see what's up. My first thought was the water pump I installed when I did the timing belt 1 yr ago.....but that makes no sense that it just fails in the mtns and cold? causing intermittent leakage. Could the timing belt be shrinking due to the cold and pulling on the water pump bearing causing leakage. I just can see that. Is the cold causing a hose to pull back and shrink...causing some leakage? Again, no apparent leakage from upper, lower radiator hoses, hard lines or tstat?
Anyone ever seen or heard of such a thing? Cold weather only coolant leakage?

vce1232000
01-11-2014, 10:35 PM
My coolant flange in back of the head was leaking only when cold weather came around[headbang]. I[wrench] replaced it. the leak was gone[hail]. The aluminium head would contract more when cold outside and the plastic flange didn't, allowing more gap for coolant to leak[=(]. The leak was in the same place as you described. Put a coolant psi tested on it and look near the back of the cylinder head and see if you see the flange leaking. Coolant usually runs down the tranny also[down]

B72011
01-12-2014, 11:13 AM
Well that's shitty news, I guess it's less shitty than the water pump going right? I'll take a look when my girl gets home with the car. I'm hoping that the coolant flange on the 2.0t isn't as much of a total bitch as is on the 1.8t. It's weird that a newer flange stops the prob..I wonder is it the rubber o ring / gasket or the plastic flange that gets deformed?

vce1232000
01-12-2014, 08:54 PM
When I[wrench] removed my housing the O ring was pretty much shot[=(]. The inside of the housing was also deteriorated from heat[confused]?. For the price of the housing [facepalm] it wasn't worth the risk of taking it all apart again. here is a DIY thread on it http://www.audizine.com/forum/showthread.php/336113-DIY-B7-Coolant-Flange-Replacement-with-Pics.

B72011
01-12-2014, 11:34 PM
Thanks. If indeed that's my issue, which I'm not yet sure it is, I'll likely take it to an Indy shop close by. I like DIYing but I've saved enough $$ over the.last couple yrs. that I can afford for someone else to deal with the headache of this job. I need to get it in the air to double check that's the issue. There appears to be some crusty seepage near a few hoses close by the T-stat, but I don't think that's it....I think they are just weeping a touch since the clamps didn't go back on exactly as they were when I switched out the t stat. It makes sense that this is the issue though. If i cant definitively see where its leaking from I'm gonna wipe it all clean from the crusty white shit and take her back to the hills next wknd......then see what and where she's draining. Thanks or the info.
P

When I[wrench] removed my housing the O ring was pretty much shot[=(]. The inside of the housing was also deteriorated from heat[confused]?. For the price of the housing [facepalm] it wasn't worth the risk of taking it all apart again. here is a DIY thread on it http://www.audizine.com/forum/showthread.php/336113-DIY-B7-Coolant-Flange-Replacement-with-Pics.