Is Dex-Cool bad?

[Tony_SS]

I had Dex mud in my old 86 c10... about a year later the intake gasket was shot... it was fixed, flushed and refilled with green stuff. I had tried to flush it before when I changed the radiator and water pump, I added green, but a week later it was mud.

I'll never, ever use the stuff.

 

[-83MONTESS-]

I had Dex mud in my old 86 c10... about a year later the intake gasket was shot... it was fixed, flushed and refilled with green stuff. I had tried to flush it before when I changed the radiator and water pump, I added green, but a week later it was mud.

I'll never, ever use the stuff.

Did you swap it into that truck? If so the problem was probably it mixing with the old stuff that wasnt fully drained yet. DexCool didnt come in anything that old.

 

[tc1959]

Been using it for twenty years haven't had a problem, See no reason to change now.
I Just do proper maintenance, test it twice a year with the test strips. When it gets weak I change it .

Dex and Intake gaskets, Have always been Intake gasket material problems. ( design ) Not the Coolant .

 

[crash]

Another good read.http://www.dex-cool.net/ And here's my own experience. I had a '95 LeSabre, 3800, 176,000 miles when I got rid of it. Always had orange (not GM) coolant and never had an intake fail or any other coolant issue, but I was on it. My Daughter had a '94 Firebird, 3.4, erratic coolant history, not well maintained, suffered a blown head gasket. No other damage or fouling noted. My buddy's Mom has a '93 GrandAm, 3.1, erratic coolant history, plastic intake, gasket leaked into motor. Upon replacing, we noted that the intake gasket was replaced prior, and had been damaged upon installation, leading to failure again. Still had the original plastic intake. And finally, when I got my '99 Sunfire, 2.2, same mechanic buddy said they "all blow head gaskets". Going on 80,000 miles and as far as I know, never flushed but always filled to the brim with the orange stuff.

I was going to also link that site in here. I know the author of that page pretty good, been on the PontiacBonnevilleClub.com forum with him now for about five or six years. The guy knows his stuff and I have run into many 3800 vehicles with the dex sludge. From what I understand though, the original Dex-Cool has been reformulated and most of the issues with the older dex issues are now gone. My 2003 Bonneville SSEi had leaking intake gaskets and dex sludge all over in the cooling system, I replaced the gaskets with the updated aluminum framed gaskets as well as flushed the system and filled it with the old school green coolant about 80,000 miles ago. The car has 230,000 miles on it now and still runs perfect with no more dex nastiness in the cooling system.

I also have a 2002 Bonneville SLE with a HORRIBLE case of dex sludge that needs intake gaskets as well as a new upper intake plenum, that will get done in the next month or so.

Right now, if the new formulation of Dex-Cool was cheaper I would buy that, but face it... you just can't go wrong with the old school Prestone.