dexcool

[flyinlow]

Replacing some heater fitting on our 04 Bonneville. I have been using dexcool antifreeze, but was considering using green Prestone this time. I have heard that the dexcool eats the intake gaskets? Any experiences with putting the green coolant in. I change it every couple years, so the extended drain is not an issue.

[terrible one]

I've also heard that the Dexcool can be hard on gaskets and seals, but have seen no proof so who knows? I'm pretty sure the "perk" to Dexcool is that it is biodegradeable. Some "green" coolants (like Prestone IIRC) say that you can mix with any color antifreeze, but I would still flush out all of the Dexcool first.

[maxwellwedge]

We call it Deathcool

[The70RT]

If you change over make sure you COMPLETLY flush it ALL out. When I did it it took like 2 hours. I drained the radiator then filled it up with water and repeated the process like 5 times till it ran clear. If you mix it it will clog your system worse.. Yeah Dextcool eats gasket and jells in the intake ports causing overheating and leaks. It will also plug the radiator and heater core.

[A383Wing]

yup...get rid of the Dexcool....use the green stuff, and like stated before, flush it all out.

in 3 years it ate my plastic t-stat housing in my wife's PT Cruiser....can't tell ya how many Ford 3.0 water pumps and GM 5.7 intake gaskets I've replaced because of Dexcool

[flyinlow]

Thanks 

I just replaced the oring heater elbows that seam to start leaking about every 50,000 miles. I had some dexcool left so I refilled it with that for now. When I can get the garden hose out again I think I will flush it out and go green.

[jaak]

I worked at Pontiac/Buick dealership for 6 years, I can't even begin to count the 3.4/3.8 V6's that had to have intake gaskets replaced due to Dexcool. In fact, we would suggest to customers buying a new vehicle to have the coolant system flushed then replaced with green antifreeze. Some would do it, some would not...but the ones who didn't we knew that would be an intake job for us in about 40k miles.

Jason

[moparguy01]

Deathcool caused the death of my wife's 99 taurus waterpump, and helped to screw up the heater core as well. I flush that junk out and go with the tried and true green stuff.

[no318]

I worked at Pontiac/Buick dealership for 6 years, I can't even begin to count the 3.4/3.8 V6's that had to have intake gaskets replaced due to Dexcool. In fact, we would suggest to customers buying a new vehicle to have the coolant system flushed then replaced with green antifreeze. Some would do it, some would not...but the ones who didn't we knew that would be an intake job for us in about 40k miles.

Jason

I was a GM dealer tech then, too, but can't blame all the intake leaks on DexCool.  The gaskets were not the best design either.  Newer, reinforced gaskets on vortecs and 3100/3400's made a bigger difference than the DexCool in my opinion.  It only turned rusty/sludgy when it got air in the system from being ran low (leaks).

[elacruze]

In the mid-90's when Dexcool was first released, the factory issued a low-level (read 'under-the-radar') TSB prescribing an 8 hour process of flushing with some harsh chemicals for cars that showed overheating. What ultimately was happening was that the Dexcool was reacting with leftover unflushed casting sand and turning to goop that plugged water passages, mostly at gasket interfaces. This should have been a recall but of course the pressure never came to do so. My cousin worked at the GM proving grounds or I'd never have found out. I've never used anything but green coolant since. I will proably use Evans in my new engine.