Dexcool

[peerson]

Sorry if this is an old topic, but I couldn't find anything in "Search". I am thinking about changing my anti-freeze to get away from the Dexcool stuff. My '96 Tahoe is beginning to experience some of the classic symptoms attributed to Dexcool. Starting to develop the "gelling" problem and my heater will not blow warm air once the engine warms-up. I have never had to add coolant. I also had the system flushed and new coolant installed (7/04). Three months later, the intake manifold gasket started leaking. Had new gasket installed and again new coolant. Last week, the heater quit working. I installed a new thermostat and heater control valve. It worked for about 300-miles before failing again. I will now have to perform a rather extensive flushing procedure to clean out my cooling system. I am concerned that my new SS has this same stuff! I will ask the dealership if changing to the old Prestone will void my new car warranty. Just wondered if anyone else has had this same problem? Has anyone else changed to the "Green-Stuff" in their SS?

 

Thanks,

 

T

[r8rs4lf]

You attribute all those problems to that type of antifreeze?

 

Late- Alex

[peerson]

Yes. After doing a "Google" search and reading about all of the catastrophic failures that are being related to the use of Dexcool (some people have had to replace their entire engine and cooling system). There are also at least 2 Class-Action lawsuits against GM for their failure to admit and fix the inherent problems involving Dexcool. I had always discounted other's "Horror Stories" about the stuff until I began to experience them for myself. My Tahoe is meticulously maintained and has never had anything added to the cooling system except Dexcool. And, then only with the complete system flush (performed at the Chevy dealership by GM technicians). There is now "jelly" forming in my cooling system. I will check the pH when I get home tonight to verify corrosivity and I suspect that it will be corrosive. I do not want this same issue with my SS! So, if I have to, I will wait until the warranty runs out to make the change in it. GM appears to be REALLY "dropping the ball" on this issue.

 

T

[DanY]

From your never having added coolant comment, I take it you never

changed the coolant on an 8 year old vehicle?

[peerson]

Vehicle only has 78k miles. Dexcool is supposed to last 150k miles between service. GM has since started recommended service at 50k. Like I previously stated, no problems until AFTER service. Perhaps I should have serviced the cooling system at 50k miles but, that is still no excuse for gelling in the system now. There are less than 2k miles since the last cooling system service. I will not take any more risks of a catastrophic engine failure due to something as simple to change as the antifreeze. If I'm wrong, I spent half a day doing the changeout (and <$100.00) If I'm right, ($$$$$????).

 

T

[PewterC3]

only problem I've heard with Dexcool is if the system is allowed to get low on coolant. That's when it gums up the works...keep the system full and there haven't been any issues?

 

My C3 had a coolant leak, was repaired and refilled...no trouble here.

[SuperDave]

I have a 1991 Silverado 1500 (350 TBI) and use it for a daily driver work vehicle. In 2002 I flushed the entire system out, changed the thermostat, hoses etc... and filled it back up with a 50/50 mix of DexCool and water. Less than a month later my thermostat housing started leaking so I replaced the O-ring in it.... still leaked after a week, then went to a stock housing with paper gasket glued on the housing side. It still leaked. A week later I flushed out the radiator again and filled it up with green stuff and the leak stopped.

 

About three weeks later, the intake manifold gasket failed and I started seeing green coolant building up in the low recesses of the intake. I took it to ther dealership to get a system flush and the gasket replaced and told the technician what I had done.

 

He just laughed... said that you are never supposed to change the coolant type. If it came with green ALWAYS put green back in it. If it came with red, ALWAYS put the red stuff in it. He told me that the two are not compatible, and it would cause the cooling system to fail.

 

Since then, I've had to replace the radiator, water pump, and it's been all good since.

 

So, I'm not touching my SS the dealership is going to do that for me, nad they will be putting the Dex Cool back in it when the time comes. My tech told me to have it flushed and refilled every 5 years or 60,000 miles... whichever comes first!

[Tony-CA]

I'd stick with Dex-Cool until the warranty runs out. I can see warranty issues arising from not using Dex-Cool. I havent seen that many problems with Dex-Cool on these newer body style trucks. Its most likely due to an enclosed cooling system(a deleted remote reservoir) as well as better design gaskets. I wouldnt use Dex-Cool in the older body style pickups though. Theres been too many problems with blown intake gaskets, leaky water pumps, and broken heater hose fittings. I attribute all of this to Dex-Cool. Ive seen this happen on trucks barely out of warranty. The fwd cars with the 3.1L, 3.4L, and 3.8L leak in the same kind of way. And some of these cars have the enclosed cooling system. The best thing to do with these particular vehicles is to flush that Dex-Cool out and replace it with a 50/50 mix of conventional(green) coolant. It wont hurt anything as long as you change it out every 2 years. Ford actually used a coolant with the same properties as Dex-Cool in the late 90s on some F-series trucks. These trucks came back with coolant leaks at the intake. Ford released a tsb shortly after instructing the dealers to convert these systems back to conventional coolant. Apparently the coolant ate up the plastic section surrounding the actual gasket which is the same thing I see occuring with nearly all leaky GM intakes.

[SSplaytoy]

I put in a gallon of the stuff with like 2 gallons of water when I did my thermostat. After reading this I might want to go green. I don't have warranty with all the stuff I have done to my truck.

[peerson]

Well, some good news! My Chevy Dealership agreed to re-flush the cooling system and replace with Green. Everything seems to be back to normal, now. Remember, I just had the cooling system flushed in 07/04 and again in 10/04. The heater core was completely full of "GOO" (less than 1000-miles since last flush). The radiator was starting to exhibit signs of gelling, too. Hopefully, the problem is successfully dealt with.

 

Thanks for all the opinions!

 

T