I had a leak recently, thought it was the lower radiator hose. Got the parts, upper AND lower hoses (no sense having a hose burst on you in 10 degree weather at night, on some back country road where the next house is 2 miles away, just change them both), took it to some mechanic for a flush and hose change. He looked at the radiator closely (thank God), and said it was rotting; the hose wasn't the problem.

I ordered a new radiator, went back today. He changed out the radiator and hoses, and to my surprise, he filled it up with 100% radiator fluid. I thought it was supposed to be a 50/50 mix of that with water. He said 100% radiator fluid is better. You can go to Alaska and not have a problem, and there won't be any rust in the radiator. I don't know how there could be rust anyways; the inside is plastic.

Bottom line, he said pure radiator fluid is better than a mix. Is that true?

Jeff 1991 300d, 116k

Jeff