Ian S.

My '98 A4 quattro (102,000 miles) recently developed a minor coolant leak as evidenced by the coolant light illuminating every couple of weeks or so following coolant top-off. Took it to my independent Audi service facility where they pressure tested and found several leaks including the water pump (which had only been replaced 4 yr and 30,000 mile ago). They recommended and performed a BG coolant system flush in addition to the various component replacements. I picked up the car Thursday. They suggested after driving for a couple of days, I recheck and top off the coolant if necessary. So I checked the coolant today and it's down a bit but the color is green. I was under the impression that only the pink VW/Audi coolant was to be used in this car and indeed, until now, that's all that's been used.

I will be contacting the service shop on Monday but want to be prepared. Is pink coolant absolutely required for the car or is there some green version that is also compatible?

quattrokiwi

they may have used G11, but I think thats more blue than green.

S4_Cinci (I S'edTFA)

G12 stuff. If the green stuff they used is not an HOAT type (hybrid organic acid technology), I would ask them to change it to one that is an HOAT. The coolant expansion tank has "G12 only" printed on it. You technically only need that exact stuff while the car is under warranty. Other types can be used, but the life of the coolant is much shorter. If they did a complete flush, the stuff they put in won't kill anything; it just ins't as long life as the G12 or G12+ stuff.