I'm driving a 97 Grand Prix GTP (the package with the supercharged 3800 engine). I've had it a year or so, it has 97,000 miles on it. I bought it from a family member. The overflow bottle and dip tube was covered in sludge (but the radiator doesn't look like it has any, as far as I can see down the hole anyway) and the radiator has the green stuff in it.
I was trying to clean the tube off, and found that the gunk was very slightly soluable in isopropyl alcohol, and that WD40 took it right off. Soap, Fantastic, CLR, Cascade didn't even touch it.
My conclusion is that the sludge is oil based in some manner or another. Any ideas on a cleaner/flush for the cooling system that will work?
I was trying to clean the tube off, and found that the gunk was very slightly soluable in isopropyl alcohol, and that WD40 took it right off. Soap, Fantastic, CLR, Cascade didn't even touch it.
My conclusion is that the sludge is oil based in some manner or another. Any ideas on a cleaner/flush for the cooling system that will work?