Sludge question

[swalve]

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?

 

[Big Jim]

That would be the "green snot of death" from silicon fallout from old style conventional green coolant. Citrus cleaners such as Prestone quick flush (or whatever they call it) do a reasonably good job.

 

[mazduh30]

My understanding was that GM's intake gasket caused air to enter the coolant system, which Dex-cool will turn into sludge. Believe there is a lawsuit(s) against GM for this problem.

 

[Chris142]

Did it swell the rubber tube up that goes to the overflow bottle? Sounds like someone mixed Dex and Green.

 

[onion]

I'm pretty sure that by '97, those cars came with Dexcool. In which case... you're looking at Dex-sludge. It isn't really there, though- you're imagining it. It never happens. And if it DID happen, then it's your fault. So just top it off with Dexcool and go on your merry way.

 

[Shaman]

IF you want to get rid of it, clean it up, and continue using Dex-cool, or clean it out, meaning turn on your heater while cleaning it, using a radiator flush or RM-125 and then swap to green or another coolant of your choosing, also remembering to turn on the heater when you are doing the flush.