steveinky

'01 A6 2.8 Quattro automatic. I checked fluids a couple days ago, all was fine and I haven't had to add any coolant ever. It Drove fine last night, no issues. This morning, right after starting the car, the big thermometer showed up on the instrument panel so I popped the hood. No coolant at all in the tank. No visible signs of a leak. Water pump changed w/TB about 30K ago, no coolant on the dipstick.

What is the most likely problem?

Thanks
Steve

clancy

Put some water in the reservoir and see if it leaks. Look around for leaks elsewhere maybe for stains the color of the coolant (pink) or whatever you use. If you cannot find any, fill the tank, cap it and start the car. Watch closely as the engine warms continuing to watch the coolant level and for leaks.

If it is not obvious and you do not see the level in the tank going down then you should take it to a shop you trust.

steveinky

So I found the leak in a hose at the back of the engine below the throttle body. I can barely see this hose. Do I need to remove the intake to replace it? Does anyone have any tips on replacing it?

'01 A6 2.8 Quatto

Thanks
Steve

SloopJohnB@mac.com

LOL...you may have to remove the engine...heck, just kidding! I don't know if this is a secondary coolant pump hose or like on my 4.2 V8 there is a pipe from the front to the back to the heads where a damned .05$ O-ring failed and I had to pull the intake manifold. You might want to look at a bentley and see exactly what hose it is.

Neosapian

Steve,

I am experiencing the same issue. A6 2.7T with 122k miles, cracked coolant expansion tank leaks fluid and I suspect one or more hoses & seals have failed as well - mechanic noticed leak above turbo and there's an odorless liquid slowly dripping onto the ground apparently from the bottom rear of the engine bay.

I am going to replace the expansion tank - $35 from ECS Tuning, flush the system, and go from there. It could be that there's a crack on the bottom of your tank somewhere out of sight. Common issue on these cars. Plastic doesn't hold up well to thermalization.

Please report your progress.

steveinky

I had a few minutes today so I pulled the air horn off the throttle body so I could see the leaky hose. On this '01 A6 2.8 Quattro the throttle body is on the back of the engine. The leaky hose is at the rear of the engine at the back of the right head attached to a metal pipe that runs between the heads. I can get at this end of the hose but can't see where the other end goes, but it goes under the throttle body or intake somewhere.

What do I need to do to replace this hose? Guidance requested from those in the know!

Thanks
Steve

lucio_liu

is it the hose connect to the upper radiator hose t fitting?

http://www.ecstuning.com/Audi-C5_A6-...oses/ES262901/

tester123

Here is some info that might help:

Coolant hose Connection diagram: http://www.use.com/10933e37aacc7369eb1e

Coolant connections on Engine: http://www.use.com/cbb47ddc83a5b196df1f

steveinky

Looking down at the rear of the engine, starboard side, just to the right of the temp sensor in the picture, connected to the tube between the heads, is the hose that is leaking. '01 A6 2.8 Quattro automatic.

Can someone tell me what it connects to and what has to be done to replace it?

Thanks
Steve

Old_School_Audi

That appears to be the cooling hose that attaches to the throttle body. The parts book lists 4 different ones.
Link to Audi parts catalog
the PN for the AHA engine is 078121188F, but confirm before you buy one.