Coolant depletion
 

All,

Looking for help. Have a 1997 Audi A8, and my coolant reservior will lose about 1" of water in 2-3 hours or so of running. I cannot find any leaks under the car anywhere, believe I have looked. The oil is not milky so it is not going there. The exhaust seems normal and is not white. Anybody have a similiar experience? My fear is somehow I am burning it through a bad head gasket.

Thanks,

RJ

RE: Coolant depletion
 

That is a pretty old car, does your coolant reservoir hold pressure (pressure test it)? The coolant reservoir gets brittle and cracks and then if it is not holding pressure it will steam off your coolant. Try the res. cap too (pressure test). If you can't find/ don't have a pressure tester (it is like a bike pump with a radiator cap) drive around and get it warmed up then open the hood and check for steam coming off. If it is a cap though you probably won't notice it.

No oil in the coolant or coolant in the oil I would say you are leaking or steaming off.

RE: Coolant depletion
 

Dont forget about the heater core. That will produce a leak under the dash.

RE: Coolant depletion
 

most common coolant leak on the V6 is below the plenum so out of sight and very hard to see, best to remove the plenum to investigate