What do you know about Dex-Cool?

GM says that the problem with DexCool starts when it gets exposed to air.. then they go and build millions of cars that use a regular old vented overflow tank instead of a pressurized expansion tank so that there is always a good chunk of the coolant exposed to air, with the hose that draws it back into the radiator as it cools sucking all the crud off the bottom of the overflow tank... this is why the midsize (W body- Impala, Grand Prix, etc) and fullsize (LeSabre, Bonneville, etc) fwd cars have problems with radiators and heater cores getting clogged and water pumps getting gummed up...

the first thing i do when i get a car that still has that crap in it is to flush it out and replace it with green, regardless of it's condition or whether it's a sealed system or not.

Jack wrote: Personally I prefer SAAB's blue coolant, for any vehicle with aluminum touching the coolant. These days I suspect every vehicle has aluminim in the cooling loop somewhere. My one GM has Dexcool, at least until I change it out. The blue will freak folks out, 'cause we all know coolant isn't BLUE! Jack

you're right … BLUE is for brake fluid ….

this is a what if question ….

there is potentially, a new GM product in my future …

would it be wise/smart to change out the coolant to a generic type ? and if so when ? as soon as I get it home ? or wait 'til it's out of warranty ?

This is the head gasket on my 96 Saturn after 235K miles. The picture was taken in Aug 2008.

Aside from an unrelated oil burning issue, the car ran fine. No coolant was getting in the oil or combustion chamber.

The car started to leak coolant just after the 100K mile mark. Buy the time I tore down the engine the car was leaking about a gallon a week. I always used Dexcool.

I'm not sure if this is a Dexcool issue or poor gasket technology.

I think the dex cool issue was primarily caused by people adding the commonplace at the time old school silicated green antifreeze to the system, and actually believing the claims by GM that it would hold up for approximately 1 billion miles. Along with taking blame for a lot of E36 M3ty gasket designs that nothing short of magic would have kept sealed. The GM method of testing new tech by selling it half developed and seeing what happens probably played a minor role. Note that the "all makes all models any color" type coolant that is popular now is similar to dex cool chemically, and works just fine and dandy with open overflows.

I know for a fact that I have had Dexcool turn to sludge in relatively healthy engines with no green stuff added in.

I hate it and will not ever use it. Ever.

Sounds like Curtis and I are in agreement on this one.

wbjones wrote:

Jack wrote: Personally I prefer SAAB's blue coolant, for any vehicle with aluminum touching the coolant. These days I suspect every vehicle has aluminim in the cooling loop somewhere. My one GM has Dexcool, at least until I change it out. The blue will freak folks out, 'cause we all know coolant isn't BLUE! Jack

you're right … BLUE is for brake fluid ….

the DOT says that blue is not a brake fluid color...

In reply to tuna55:

Ditto, granted I'm a C.A.L. member for that whole mess for a 4.3L. It was a problem for sure.

5 year old thread

novaderrik wrote:

wbjones wrote:

Jack wrote: Personally I prefer SAAB's blue coolant, for any vehicle with aluminum touching the coolant. These days I suspect every vehicle has aluminim in the cooling loop somewhere. My one GM has Dexcool, at least until I change it out. The blue will freak folks out, 'cause we all know coolant isn't BLUE! Jack

you're right … BLUE is for brake fluid ….

the DOT says that blue is not a brake fluid color...

sorry … I didn't put some sort of sarcasm emoticon after my post ..

but just for those that might care… I have 2 cases of ATE blue … reasonably priced ( the ATE amber is the same stuff, just not blue)

I flushed the 9C1 after I got it in 2000 and brown poo came out. Green back in. Happy squad car.

Zomby Woof wrote: 5 year old thread

Geeze... I remember beta testing this board. Remember the old green/black board before this?

It may be a 5-year old thread, but it's a great opportunity for some good old-fashioned GM Deathcool bashing!

My uncle used kerosene as anti freeze in his Jeep pickup.

Zomby Woof wrote: 5 year old thread

which someone brought back up (wasn't me, even tho it looks like it... there's a few posts missing that were there yesterday..).. it's always good to remind people of the evils of DexCool..

Does Hennessy Honda promote the use of Dexcool?

In reply to Brett_Murphy:

Yes, especially in honda cars with green coolant.....make sure to mix the two well......

I believe its called signature service.

Re-reviving this thread. My new to me Safari van has what looks to be dex-cool in it. I'm thinking drain, straight water flush and fill, drain again and refille with zerex Z-05. Anything else I should do?

In reply to bgkast:

Pull all hoses and thermostat, garden hose the hell out of everything, reassemble(probably not a bad idea to replace tstat), refill with cheap "all makes all models" stuff, drain and fill radiator every year or two.

02Pilot wrote: This is not normally a problem, but GM had a bad batch of intake manifold gaskets on one of their common V6s that allowed air into the cooling system, which caused the Dexcool to turn into pudding and made many owners quite unhappy with it.

If by "bad batch" you mean "everything with a plastic gasket" then yes. Air entrainment and overheating turn Dex-Cool into mud.

Universal long-life are still ethylene glycol. The stuff we use mixes with everything, even the 14 different flavors of VW coolant. We only use OEM coolants if the car we are working on is still under manufacturer warranty.