ok guys im stumped. im loosing coolant over the coarse of a week i have a 96 a4 quatro. i drive the car back and forth to work and at the end of the week the resivoir is close to being empty.i just replaced the timing belt water pump and drive belts along with the thermostat. i went back and double checked all of my work.on another note im not able to get heat to work in the car this year either i checked the coolant lines running into the heater core there isnt any air coming from them when i do a bleed test and there seems to be a good flow of fluid.

i did a block check for a solid 15 minutes and couldnt find any hint of co2. i dont have the cap to do a pressure test but with the leak being so slow i dont think that would help much. i realy want to fix this problem. does anyone know of anything i should be checking? does anyone know of a company making a UV dye for coolant like they do for oil and A/C and such? any help would be awsome i love this car the leather still looks like the day i bought it and the body is awsome too!

 

Pressure test is to start with (besides the visual check).
Dye and black light shout be an usual tools of any radiator-cooling system repair shop.

 

There's a chance that you're burning the coolant off through a head gasket leak, but the fact that you're not getting heat seems to indicate a heater core problem. You say you're not getting any air leak - are you getting any coolant leak there? Any coolant on the ground or on the bottom of the car in that neighborhood?