The coolant leak decision....

[LuRS6]

Hello RS6 world, I recently purchased my 2003 rs6 with 117k miles for what I thought was a steal because of a known coolant leak and brakes beyond not working. now I am a pretty savy mechanic, and I inspected the car when I arrived at the dealer. We put it up in the air And everything. I could smell the coolant but where it was leaking from was a mystery at that moment. Other than the leak the rest of the car was sharp. Drove home made it no problem.

Fast forward about a month of knuckle busting fun and I finally track down the leak. After I removed the intake manifold it was down to two locations. I could see the pool of coolant laying in the valley but tracking the origin was tough. Then I noticed a clean spot on the front left head below a aluminum coolant pipe that bolts to the passenger head and runs to the rear. It looked OK but after removing the pipe and gasket I could see that it had not failed. Then the AH HA moment, there is a black tube that runs from the back of the thermostat housing to the firewall. After looking online it has a O-Ring that seals it to the block. This had to be it.

But after studying the hard pipe there is absolutely no way to remove the pipe with the engine in the car. First it has a mount bolt facing the firewall and then the pipe runs right next to the MAF housing. I mean Millimeters. If I ever got that bolt out how the hell would I get enough clearance to back it out???

Now the decision, I could have JB welded around the pipe and Hope and Pray that it never leaks, but that's not good enough for The RS6 if its bad now it will only get worse.
So I decided to cut a section out of the pipe which gave me clearance to back out the pipe from the thermostat housing and maintain enough free pipe to place another hose on to rejoin it.

Sure enough after removing the pipe the O-Ring was toast. Hard as a rock and flat as a pancake. I'm glad I cut the pipe to get access to o-ring. The joy in knowing where it was leaking from is worth he pain of cutting the pipe.
So far I've ordered the oring and gaskets needed for both pipes to seal as they should.
Has any one had a leak from this location before??

[LuRS6]

[nubcake]

Your SJP is broken.

[LuRS6]

[LuRS6]

On order.

Your SJP is broken.

[LuRS6]

[P1054]

I have mine on an engine stand right now. That valley pipe wasn't leaking, but I'll be replacing the o-rings, especially after reading this. It's easy to do right now, and cheap. Less that a buck an o-ring.

[RS Sick]

Might as well get that after run pump done while you're in there.

[AndyRS6]

What brand of CCT did you get? Are they genuine Audi?


Andriy

[LuRS6]

The after run pump was already changed. I'm guessing previous owner was looking for the same coolant leak and the shop sold him on the leak being from there. As we now know it certainlywasn't. I'm guessing after the previous owner spent a couple thousand on that repair, then only to have the coolant still leak it was traded in.

[LuRS6]

I went El Cheapo "China Brand" sounded like hell on first start up but it sounds proper now. Searched a lot on the forums for information on the China brands but no good reviews. I'll keep you updated on their performance.