Dex-Cool

[23hotrodr]

For all of you with a GM 8.1L engine, do you still use Dex-Cool, or have you switched to standard Long Life anti-freeze in the cooling system?

[Deano56]

Dex Cool has been referred to death cool in the early 2000's. The GM 3800 was notorious for lower intake gaskets going bad because of the plastic gaskets being destroyed by the coolant. They (GM) switched to aluminum intake gaskets in 2005 I think, someone might know better about the date. Since the change took place I have not heard that there is a problem with that coolant. We drive older GM cars that are from that era (2002&2003) and both our cars have had the gasket replaced, the Buick I did just two weeks ago. I have read that dex cool actually dissipates the heat more rapidly than the older coolant. One thing I do know about Dex Cool is, that you cannot mix the green coolant with it, it will turn to gel, all has to be flushed if you want to do the switch, even though I don't know why anyone should.

[noleakman]

I was in the radiator business for 30 years and I can tell you Dex Cool is ok if you change it every couple of years! I have changed radiators with 60.000 miles that were all full of gunk It is true about the class action law suit it goes bad and eats gaskets and if you mix with regular coolant it can turn to lime green jello! So just change and flush with distilled water running a couple of times and add half the ammount of straight coolant and the rest distilled water to fill and flush plastic bottle and add straight coolant to it! it will mix with the radiator mixture! Buy a good cap at the GM dealer not one for 2.95 at Pep Boys you get what you pay for!

[Ventureman]

I've been through the Dex Cool ringer twice on my minivan with 3.1 engine. It basically dissolved the intake gaskets. Joined a class action lawsuit but GM went bankrupt in the meantime so I'm sure I won't see one penny! That being said if you do use it be vigilant with coolant level and oil purity.

Gaskets blew (there are two; upper and lower intakes) a third time. Put in some "stop leak" and traded it!

I don't think it was the coolant as much as it was poor design of the whole cooling system. Hopefully GM learned.

[rgatijnet1]

If it has never had the coolant changed, it is overdue, which may explain the scum that you see.
The Workhorse owners manual calls for Dex-Cool to be used. It does not specify an alternative.
Anything else that you use is your choice.

[KJINTF]

Dex-Cool here as well
Clean, Flush and Exchange ALL of it every 4 or 5 years (20k miles maybe depending on the trips)
Time not Mileage is my concern

Looks as if you are WAY past time for a good Flush / Replace
The Prestone all makes all colors will do the job as well
If you change colors suggest you get it ALL out (heater core, block, radiator, etc....) and cleaned properly

[23hotrodr]

Are you guys using the GM recommended 5 year or 150,000 mile change interval?

The new to us 2007 Itasca Suncruiser 35L does not appear to ever had the coolant changed and there is some scuzz lining the radiater fill tube.

I need to change the coolant and with the gazillion complaints out there about Dex-Cool, I'm not sure what to do.

[harold1946]

Dex-Cool here also.

[rgatijnet1]

I still use Dex-Cool and after 80,000 miles I see no reason to change. Since I do most of my own service work, I do not fear someone adding a coolant that is not compatible with my Dex-Cool.