Lionheart1019

My 2003 A4 3.0 Quattro recently started leaking coolant from the reservoir. The leak seems to occur when the car is stopped after it has been driven and it empties the reservoir within a few hours. Naturally the car signals me with the dreaded low coolant dashboard warning. Liquid is pooling around the front motor mount and is dripping to the floor in a noticeable puddle. Checked it with the old man this morning and there does not appear to be any hose or reservoir leaks that we can see. He thinks it could be a bad water pump. I have been keeping a close eye on the temperature gauge while keeping a fresh supply of distilled water in the reservoir and the gauge has remained at its normal operating position. Any reliable methods of testing water pump performance or finding sources for coolant leaks would be greatly appreciated.

TLR - Need assistance in finding the source of a coolant leak.

gsjohal

The only test for the waterpump, apart from a visual for leaks, is to check the flow being generated by removing the little return hose on the reservoir and revving the engine. Remove the cap and aim the hose back into the reservoir. You should see a healthy consistent flow through the hose as the engine is revved by a second person.
However as you say the vehicle isn't overheating, a pressure test of the coolant system with a handheld tester is more appropriate. It screws on in place of the reservoir cap, pressurising the system to highlight a leak.
Have a close inspection of the radiator too.

mrmnico

I had similar issue but it was my rear collant flange which I had replaced at dealership