I bought this 2001 A6 2.7T 2 months back,this otherwise nicely running silver beauty is slowly loosing out coolant.
Took it to a dealer last month for service who topped up the coolant and asked me to come over if level drops again.
yesterday while driving the coolant low light popped up on display i checked to see the level is wayyy below minimum .
I dont see any puddle trickling when car is parked or any coolant dripping ...... any clues as to where the leak might be happening.

 

Try and look down underneath the intake manifold. That leak also usually runs down over the bell housing on the transmission.

There's an excellent tech article on AudiWorld. If that's what it is, the part is ~$170, and labor is ~3 hrs.

I paid ~$450 at an independant shop. I would do it myself now.

Tech article on AudiWorld

 

I just replaced my coolant reservoir which had a pinhole leak on the bottom (I have a 99 A6 2.8 avant Q). It would only leak after the car was driven for a while. It is a 35-40 dollar part and it takes 10 minutes or less to replace. that may be an inexpensive start. They fail often anyway so you'll probably need one sooner or later....

 

seems like I too have the leak at intake manifold... the coolant leaks drop by drop over the transmission bell when engine is running.
can you please tell which al parts were replaced to fix this problem in your car

 

Auxillary coolant pump or after run coolant pump. Two names for the same part.

 

part numbers are in there.

 

I enjoy a 2003 A6 2.7T which started losing antifreeze at just over 50K miles (naturally, just after warranty expired). It appeared to be leaking down the back of engine/transmission housing. Local shop offered to pop head and replace gasket for ~$900. I opted to buy the most expensive bottle of radiator seal I could find ($7) and put two treatments through the radiator overflow tank. Problem has not recurred and I'm at 74K miles. Nor has it gummed up the radiator nor overheated.

I've always been suspicious of the cheap fix but this treatment seemed to just swell the gasket enough to seal a very small, but annoying, leak.

Good luck.

 

sounds like this can fix my issue as well... do you remember the brand /name of sealer you used?

 

(I just got bounced off the server so apologies if this is a duplicate posting.)

I don't remember the brand. I spent 20 minutes in Walmart reading all the packages and selected one that emphasized gasket leaks rather than radiator leaks. The latter have aluminum particles that scared me - afraid of gumming up the core. I poured half in the overflow reservoir and topped it off. A week later I repeated and have not had a problem since. Before that the reservoir alarm was coming on at least every other week.

Good luck and let me know if this solves your problem.

 

I have the same thing going on now and the dealer said it the the aux coolant pump. I read an article where someone tried to do it himself and he found that he did in fact have a leak but it was due to the cheap spring clamps that hold the rubber tubing onto the aux pump under the intake manifold. He went to the store and purchased a few of the clamps that screw down to tighten and that fixed it! Paid $8 for clamps when the dealer told him it was the pump and that would've cost him $650.