Lord_Galva

So I've been hunting on this forum to find any insight into what is wrong with my mother's 2.8L. I was told the coolant was leaking out really bad and I came anticipating a bad WP or thermostat. I see the car and the puddle is behind the front wheels. I pull all the plastic intake stuff off to observe the heater core lines only to find them dry and healthy. CEL code 16501 16501/P0117 - Ross-Tech Wiki

Based on the process of elimination, this forum, and the code, my problem is coming from the rear coolant line. Ideally I'd like to change out all the seals on it, but if anyone has done this job before I'd love to hear some insight.

On a side note, it only seems to leak when stopped. I drove it to a local store 2 miles from my house and I saw fluid dripping out in the same place behind the wheels. I raced back home keeping my eyes glued to the temp gauge with the heater blasting. The weird thing was, the temp gauge only started one click to the right of normal and mid way back the temp was normal.
I found out from my mother that she had driven it nearly ten miles like that before it dumped most of the pink stuff all over the street after an earlier boil over. They are not too happy about the wasted pink gold but I've never heard of a coolant leak like this.

Airbag

I think rather than process of elimination i would want to see exactly where it was leaking from . unfortunately i have not done the coolant lines of which you speak myself. Just check the coolant reservoir very carefully , even undo the three screws and lift it out .. if its the lines behind the engine that sounds like a real pain .

I hear you about the pink Gold. i am sure someone on here may know of a substitute. I have heard that peak Global will work but i cant confirm . may require entire flush to remove g12 .

Lord_Galva

It is a pain. The rear lines are all under all the intake stuff so you can see but not touch them. I am trying to verify the exact source before buying parts.
My next step is to: warm up the engine again to try and get a leak going, then take the intake off so I can get my hands back there to track down the leak. Unfortunately I don't see any other way to do this.

georgeb944

Get yourself the kit to pressurize the cooling system. It's a lot easier to look for a leak when the engine is not trying to set your clothes on fire. Yes, it's not cheap, but cheaper than throwing parts at it.

SloopJohnB@mac.com

No…it's rather difficult and irritating to do it that way.

You can drill a hole and screw in a tire valve stem from an alloy wheel (or glue in a rubber one) in the reservoir cap…drill so you don't destroy the vacuum and pressure relief in the cap or buy a new cap when you're done.
Then use a tire pump to pressurize the system.

A complete Stant coolant system pressurizing kit and the euro adaptor to Audi screw-in caps is probably around $72 plus $30-50 for the adaptor.
The Stant 12036 adapter is needed to screw into your reservoir, $50 cheapest from Amazon. A diffo 12037 is needed to test the cap itself.

Lord_Galva

Wow, I never thought of using a tire pump to pressurize the system.
I could definitely try modifying something with my Motive brake bleeder.
But wouldn't the thermostat prevent the pressure from getting to all of the engine?

Oh and I don't mind doing irritating things. I wouldn't have owned/ worked on eight different German cars if I didn't mind ridiculous positions, tools and procedures.
German FTW

georgeb944

The pressure gets to all of the cooling system, and both sides of the thermostat.

Lord_Galva

So this is pretty crazy. I could not get the system to leak at all today.
Instead of pressurizing using a pump I merely drove the car various distances close to where I was working. I drove 5, 10 and 15 miles with the a/c on and na-da. Not only did it not leak but the level in the reservoir stayed constant.
I'm going to count my blessings and leave well enough alone.
Just in case, I put a gallon of distilled water in the trunk.
On to the next G-car