Hi I own a 1995 audi a4 2.8 quattro how would i know my heater core is leaking or just water is leaking in from somewhere? I think its the heater core cause there is slight water leakage on my passeger side floor matt in the middle where the 4 rings are by the holes where the floor matt clings to!!! and if so is it a dealer item cause i think i can get it at my work (1800 radiator )

 

can you smell the coolant ( a sweet smell ) if not then its probably not from the matrix plus you would have to fill the coolant up all the time which tells you the coolant system has a problem and you would have problems with heat due to air locks,

check below the windshield for blocked drains

 

If you do NOT have a sweet-smell, along with teh leak, and/or a need to constantly re-fill your coolant, do a search for "drain plugs" in the a4 section. Someone there will have posted where you need to look & how to go about cleaning them. When they are plugged up they tend to overflow into the passenger foot-well.