N2AK

Since I bought my new 2005 A8 I've religiously followed all dealer services. My son laughed at the suspension until I encountered a rock in Denali which I was, literally, able to rise above. TWO Feb.s ago I took the A8 to the dealer for a coolant leak & was informed that the car was "toast" (head gasket) so I left it there & drove my other 3 Audis. After 1 was stolen I drove the A8 home. MP 4.2 suggested that the cap could leak & so I bought a new cap & it runs fine. I was told I had coolant in the oil. Wrong. I took it in for a hard start & was told that because of the head gasket leak they could not fix the hard start. Proud of my Irish traditions, (& Mishar's advice) I procrastinated & drove on & the hard start disappeared. BUT, I still have a slow coolant leak which really doesn't bother me (I can actually add coolant). I have no coolant in the oil & vice versa. No spots on the driveway. Occasionally, the CEL light comes on so I wait a minute & start it again. No problem.
So my question is, at 135,000 miles, should I do anything? Just soldier on? And why am I an Audi Newcomer?

Junius

Have you checked the oil cooler? Common place for slowly progression coolant leaks.

Junius

Have you checked the oil cooler? Common place for slowly progression coolant leaks.

dvs_dave

+1 on the oil cooler. There is a plastic stub pipe that feeds coolant into the oil cooler heat exchanger. Over time this pipe deteriorates/cracks and causes a slow leak that progressively gets worse. There is an upgraded aftermarket aluminum one available these days. Google "bufkin pipe". It's a PITA job to replace and your dealer will tell you it's an engine out job. But any specialist worth his salt knows the workaround and can do it without pulling the engine. It's still a 6-8hr job though.

03_AR_CO

Search gruvenparts

4.2L Audi/VW Billet Oil Cooler Tube - Gruven Parts

the_duke

+1 on Gruvenparts.

But of course you need to find the leak first. My oil cooler pipe didn't leak slowly. It went from not leaking to dumping large amounts of coolant. Another spot to check is the heater control valves and the related hoses. They are hidden under the plenum cover and if they leak you often won't see it unless you look under there.

Giovanni Giovino 6.0+6.0TT

Check all the plastic lines for pinholes and leaks at connections, when I received my W12 it had low coolant and I found a few leaking ever so minutely, BUT leaving a pinkish residue behind.


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