Don't make my mistake

dwna1a

dwna1a

Well-Known Member
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Apr 23, 2012
5,981
James River
Boat Info
88 Weekender 300 "Seahorse"
Engines
Twins 350
In 2005 I bought my wife a Chevy Equinox with the V-6. We've owned that thing since day one. The car has been serviced every six months. Never once has anyone said anything about the coolent (and never did I look at the manual) My wife went to use the car last week and came in to me fussing that the car wouldn't get warm. Me, I'm thinking thermostat is stuck, so I dropped it at our shop. Well I was sorta right, it was the thermostat as well as blown head gaskets and two cracked heads.

Seems Chevy, as well as the other carmakers, changed the coolent in their engines. It can't be mixed with any other coolent on the market. When you do mix it it turned into a jelly and clogs all the passages inside the engine. This mistake will cost me about $4500.00

Im taking my truck in next week to get my engine flushed out.
 
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It also is corrosive to the water pump gasket. Had to replace the one on my wife's 04 Tahoe last year.
I flushed the system and put regular antifreeze in.
 
Holy cow, that sucks!
 
Dexcool - We have an 05 Saturn Vue V6 with the Honda 3.5l engine in it (the only thing that is solid in the Vue - everything else rattles and is falling apart). I just had the 100K flush, timing belt and water pump replaced, etc. All replaced with dexcool again. Sorry to hear about the troubles.
 
Well I learned something important today. My wife has a 2012 GMC Terrain that (knock on wood) we've had zero issues with. Now that I know about the issue with the coolant I will watch for that.
 
Check first and see if it has Dexcool. Once GM found the had / have a problem with this coolent they stopped using it.

Lastnight I found a TSB on the issue. Dated Jan 2008 advising not to mix coolent but to remove the Dexcool and flush the engine. Then replace with Delco coolent. This is my fault just as much as it is GM's. I should have checked the book for its 100,000 mile service. With it being serviced every 6 months I never thought of the coolent.
 
I have a 2009 Arcida, the drivers power seat failed in 2015. I took it to the dealer and the cost was $800.00, I contacted G.M. customer service and they got back to me next day with an offer of G.M. pay 45% and I would pay 55%. Sounded good to me since it was way out of warrenty. When I picked it up after the dealer said G.M. said since I was nice to them they would go 50%-50%. Very Happy
 
Coolant compatabilty is important on boats as well. Make sure you check when adding or changing. Owners manuals speak to this issue.
 
dwna1a said:
Check first and see if it has Dexcool. Once GM found the had / have a problem with this coolent they stopped using it.

Lastnight I found a TSB on the issue. Dated Jan 2008 advising not to mix coolent but to remove the Dexcool and flush the engine. Then replace with Delco coolent. This is my fault just as much as it is GM's. I should have checked the book for its 100,000 mile service. With it being serviced every 6 months I never thought of the coolent.
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Who was servicing the vehicle? If it was GM, they should have addressed the TSB during routine service.
 
After GM dealer screwed up my Silverado I switched to my local shop. They had not seen the TSB but knew GM had been having this issue. They only opened their shop about 4 years ago.

They stepped per up and fixed the truck, but that was a complete rebuild at 110,000 miles. They also said they would do a 40/60 split. They finally saw the light and did the work at no charge. That's another story.

And no dealer I know will advise a owner of the TSB. They will only tell you about the recalls.
 
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From what I've read, Dexcool is NOT the problem. Your V6 engine was originally built using the wrong head gasket material. Your incompatible gasket material is being eroded by the Dexcool. The 8.1's powering my boat use Dexcool but they were built with the proper gaskets. Also, Dexcool does not take well to mixing with regular glycol - it will form gel. It is not a good idea to swap the coolant since it it virtually impossible to remove all of the Dexcool no matter how much flushing is done. You may find that the new head gaskets are a different part number than OEM...

This is from articles I read when I first went to replace my boat engine coolant and had heard nightmares about the product. Although this coolant is used in many different engines, it was only a problem with certain V6 engines and other engines where regular glycol was added after the fact. If Dexcool was the problem it would be affecting all engines using it.
 
dwna1a said:
Seems Chevy, as well as the other carmakers, changed the coolent in their engines. It can't be mixed with any other coolent on the market. When you do mix it it turned into a jelly and clogs all the passages inside the engine. This mistake will cost me about $4500.00
Click to expand...

Thanks for the heads up, sucks to learn a hard lesson.

Last year we bought a 2014 Cad ATS used CPO with 7,000 miles on it, for the first time ever we bought the extended premium warranty it covers everything till 2023 belts, wipers, oil & filter changes, air & cab filters all electronics & drive train everything bumper to bumper with a Cad loaner car for any service over 2 hours.

I knew the finance person he has a 330 Sundancer he told me to please read all the fine print on the maintenance schedule and make sure to follow it using only a GM certified CPO facility preferably their's. In the fine print it states any work performed by any NON CPO dealer must be pre-authorized by GM or it could void the warranty. If I'm on a trip out of state and there is no CPO dealer they will pay to have it transported to the nearest facility & get us a loaner or rental car.

I've learned to read all the fine print from now on.
 
Sounds more like Dex(un)cool to me......
Sorry to hear about your problem. It never would have occurred to me that this could be a problem.


Sent from my iPhone using Tapatalk
Todd
 
carterchapman said:
My previous boat's 8.1's used DexCool as well...probably in all MerCrusier engines after 2000 or so...
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It's important to check the ph on coolant every year and change it out when its ph reaches the level specified in your owner's manual.
 
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