acarney

So I finally have a little time to break down the car again and figure out where this slow but steady coolant leak is coming from. Leaking from front-ish of engine on the passenger side. I have attached a video showing the leak the best I can, please forgive me if it's kinda crappy as I was trying my best NOT to get coolant on my iPhone and leather case, lol.

I recently replaced my water pump and gasket as well as thermostat and o-ring. Thought I did it correctly as I cleaned the mating surface the best I could and followed torque specs. Haven't completely pulled the belts off all the way but that's what I'm going to do next. Was just hoping some of you could maybe guide me to what to look at first, especially because I've got to remove the lower radiator hose to gain a little more room to remove the belts etc. This will drain the coolant and thus no leak to follow any more.

Hopefully it'll be really clear with a wet area where it's leaking from or something, or once everything is removed I'll reattach the hose and fill with distilled water to see if it leaks again where I can observe it... but still, where to look first?

sounddude

You've got to take it apart but it does look like water pump.

acarney

Water pump was actually fine!! It was the thermostat... It's all pulled apart right now and jut waiting for me to get home and replace/put it back together.

Gsrob

Awesome, glad you found the issue. Did the gasket not seat properly or what was the problem? I can't remember if you said you were going to clean up the mating surface or scrap the thermostat and replace it...

Edit: Just saw that you replaced the housing. Good find!

acarney

I did all three. I had ordered a new o ring just in case the aftermarket one maybe wasn't the exact size or something and then I was worried maybe the after market thermostat wouldn't be a perfect size with the Audi o ring, so I ordered an Audi thermostat. Then got the new housing just in case there had been a hairline crack in that somewhere. The mating surface actually looked really clean, but can't hurt to clean it more.

The only thing I can think was the service book says to lubricate the o ring with coolant before you install it. Almost sure the blau parts instructions didn't say that. Maybe that simple step was the cause of my leak...

Filled it with coolant last night and I'll check it for leaks after work tonight. If no drips or leaks anywhere around the housing or on the underside of the car, I'll call it good and button it up!