Audi_1999Man

What does it mean if I keep losing coolant in the reservoir tank but it's not leaking? 1999 audi a6 Quattro. Thank you.

thall6594

I recently had the same problem on my 2002 3.0. It was a leaking head gasket.

Does the exhaust smell sweet when you start it? Any smoke clouds on startup?

Audi_1999Man

It doesn't smell sweet & there no smoke clouds. The car just gets hot overtime. Smoke did originally appear from where the T connector was but I replaced that so there's no smoke.

SloopJohnB@mac.com

It means you have to pressure test the system and figure out where the leak is. Do you have chocolate mousse on the dipstick?

There are test kits/procedures for head gasket leaks that check for combustion products in the coolant, relatively cheap ($30 or so) compared to taking the car in and losing time, etc.

How much/fast are you losing it? A quart a month? A week? A day?

Sometimes they only leak under pressure/driving…you could have a water pump seal leak and it drains down and flies out while driving. Or a pinhole leak somewhere else.

Osmosis

Where can he purchase the pressure test kit for life cars? That kit is great advise😀

Just Me

Why do you say it is not leaking? That's a hard thing to ascertain. I bet it is. If its really not leaking, you have a blown head gasket.

Grant

Just Me

You mean steam, not smoke, right? That aside, leaks can be very hard to find. What you often have to look for is a small amount of colored residue - pink maybe in your case? Or blue/green? whatever your coolant is. The overflow itself is notorious at seam points such as the sensor hole, or the point where the two halves are joined. Then various hoses - particularly where they are clamped.

Finally, the water pump will often leak when it begins to fail.

If it is getting into the motor itself, it almost has to be passing the head gasket. That should reveal itself as steam from the exhaust. Maybe nto much though.

Grant

nicaudi

I had the same issue on my D2 A8, , i know different engine, but the issue could be the same;
THE oil cooler on these audis have a plastic pipe that will sometime melt - causing a coolant leak.
I replaced my with the "bufkin" milled aluminum pipe - my local indy shop did it for ~$350 (another indy shop [Eurowerks in falls church, VA] said they had to remove the engine / front end of the car and it would cost ~$3500!!!), I questioned them, on this, but they were insistent,on the labor and methods)
NGP in lorton, VA did it for $350 - of course there was no need to remove engine/front end........

Look up Bufkin in the forums and you will see it

The coolant leak was substantial - i had to top up every week (with light driving) . you can see some coolant pooled after you park.