Extended life coolant

2006 GM truck has dexcool in it heard it has caused a lot of problems,should it b replaced with prestone or something or put dexcool back in .

I would get the Dex out of there. I believe the best way is to have it put on a flush machine. Then replace with one of the universal coolants on the market, and drain and refill again after a few thousand miles. There are reasons that it is sometimes called “Death-Cool.” I don’t know about the gasket eating properties, but I can personally attest to the brown sandy sludge problem.

Yup! It happens if air gets entrained into the cooling system. DexCool turns acidic if this happens where other OAT coolants don’t. And then end up with the sludge/rust that cigroller describes.

Bring it to someone who has a coolant exchange machine, and I guarntee you they’ll run it until the orange color of death is removed.


I’ve used dexcool in several vehicles including non GM cars and trucks. Never had a bit of trouble with it and I’ve kept it in two of the vehicles for 7 and 8 years respectively. GM has had gasket problems, as had Ford and the coolant isn’t the problem.

What is the Ford gasket problem that you refer to?

We have had several cars and have two right now with Dexcool. None have given trouble. Make sure that you always have a good radiator cap. My 96 ran well over 130K miles with the original cap and with Dexcool until I traded it. Other cars to trade time ran 35k and 70k miles; no problem with Dexcool.

I think if it is still under warranty, you should continue with GM’s recommended coolant. After the warranty expires, I would get the Dexcool out.

I have heard horror stories about air getting in to the system, and I have heard horror stories about people accidentally mixing it with the wrong coolant. You may never have these issues, but I prefer to play it safe.

3.8l engine used in early to mid 90’s