I know there has been previous discussion about this so I thought I'd put out my experience as it relates.<p>Brought my '96 A4 in because the coolant had changed color from dark blue/green color to brown. I am not a car wizard but every other vehicle I have owned you need to change the coolant at least every few years... yet Audi does not recommend it nor cover the change of it under the Advantage program (kinda like the fact they don't cover beyond 7500 miles tire rotations). Anyway, the service writer advised me that it should be done regardless and quoted me some outrageous number to flush the system and change it. Here's the kicker, went out on a drive with the mechanic so he could hear a noise (I had the same rattle everyone else has in the driver's B-pillar) and discussed the coolant issue with him. He advised me to tell the writer the coolant light stays on too long upon starting the car and leave it at that. Well, you'll never guess... they covered not only the change of coolant, but also to flush the system. Even better, they replaced the coolant reservoir (it was discolored from the dirty coolant). What a deal!

I've noticed that my coolant reservoir is now brown in color and the coolant is likewise a brownish shade also. It is on my list of things for my next service. Seems quite strange. Any clue as to what is causing this?<p>Sean<br>97 1.8Tqm<br><ul><li><a href="http://www.seansa4page.com">Sean's A4 Page</a></li></ul>

I asked the mechanic what would cause the change in coolant color and according to him there is nothing to rust within the radiator or engine block (I am not sure if that holds true for the 1.8T as I have a 12V 2.8, but I'd go out on a limb and say it does). Hisbest guess is that it becomes soiled from prolonged useage (What do I know, my wife has a Toyota Corolla that we changed the coolant after two years and it was as clean as the day we bought the car). <p>I too was concerned about the reservoir color and had been mentioning it to the dealer the past 6 months. All they would say is the coolant was still effectiveafter testing it and the plastic was what was changing color (not the coolant)... and ultimately not to worry. Funny how the story changed when I brought it in this time as the told me the cooalnt was not dirty but filthy. I've come to think the maintenance list is not always an accurate source. I know the newer models have "lifetime" coolant, but for the older models I'd suggest changing the coolant every two years regardless of what the dealer or Audi says.

My '96 owners manual doesn't state to change it, just to check the level. Never owning an Audi before I assumed the dealer knew what they were talking about by not needing to change it. Guess I learned not to trust the "experts" and use my best judgement.