: dexcool flush



parts68
06-25-06, 09:50 AM
Doing my routine maintence on one of my other cars.
I picked up a one owner 97 FIrebird and owner admitted he hadnt
kept up with routines as good as he should. Car has 50K on it so I decieded
to do a radiator flush and refill with fresh Dexcool.
Sorry no flames on this as I m still using it in all my GMs that came from factory with it.
I have a comparision pics of the drain of my 96 Rora which has had 2 Dexcool changes
since new(now the 3rd) and the dreaded brown crap that came out of the Firebird.
Question is ,is there a good solvent,flush chemical, that will remove the slude thats left?
Its not bad but I like my cooling systems to be squeaky clean inside.
Yes I wont wait this long to change it as the PO did.

JimD
06-25-06, 06:01 PM
.... and the dreaded brown crap that came out of the Firebird.
Question is ,is there a good solvent,flush chemical, that will remove the slude thats left?
Its not bad but I like my cooling systems to be squeaky clean inside.
Yes I wont wait this long to change it as the PO did.

If what you are seeing is the GM coolant supplement (or Bar's Leak Golden Seal) that has dropped out of solution, I would not introduce other chemistry to remove it. That trace of brown is harmless; it is just not pretty. In fact, seeing traces of the supplement in the system tells you that you have at least enough of the supplement in there to take care of nuisance leaks.

My '98 has shown me the "brown crap" for more than 145,000 miles and I just grin because I know it is not rust.

Drain it, mix up some 50/50 Dexcool and water and refill.

Ranger
06-25-06, 08:27 PM
Is the engine in question all aluminum?

parts68
06-25-06, 09:32 PM
no its a 3.8 cast iron and aluminum.
This is the slimy brown sludge that forms when
Dexcool is continually left exposed to air.
These cars are real hard to purge all the air out,have
a bleeder screw on the tstat. No telling how the PO
let it get this way.
I dont think its sludge from a sealer, nor rust,its too slimy

Ranger
06-25-06, 10:34 PM
Ah, that splaines it.

parts68
06-26-06, 06:38 PM
so how to clean it up????

Ranger
06-26-06, 08:33 PM
I would probably just flush it with water. There are also several different flush addatives that you put in the system, run the engine for a while and then flush them out. Some of the stronger ones use a neutralizer afterwards, then flush well.

parts68
06-27-06, 04:42 AM
done the water flush
Looking for first hand experinace with the Dexcool slime issue,
wanting to hear of whos had success with what product,and no ill affects.

GreenMachine
06-27-06, 01:03 PM
A good family friend found a solution on his (I think) 96 or 97 S10 pickup. Unfortunately it was a switch to the green stuff....His heater core kept getting cloged and when the flushed it the brown sludge came out both times.

On my 98 deville when I did the coolant service I didn't have much of anything in there but a darker dexcool with some tiny lumps.

Ranger
06-27-06, 02:40 PM
A good family friend found a solution on his (I think) 96 or 97 S10 pickup. Unfortunately it was a switch to the green stuff....His heater core kept getting cloged and when the flushed it the brown sludge came out both times.

On my 98 deville when I did the coolant service I didn't have much of anything in there but a darker dexcool with some tiny lumps.
That sounds like the cooling system suppliment.

parts68
06-27-06, 06:21 PM
I think that most of the ill effects are from other than N* GMs.
Checked my 01 S10 just under the fill area on radiator and its just starting to get a little.
I will change it even tho is got 27 K on it. No need for a flush as its nice and pink.
Ill ask my son who works at a GM dealership(sometimes its best for a group of enthusists
opinion tho)