DexCool Anti Freeze

Engineer · January 15, 2004

I was just wondering if any one has replaced the anti freeze in their truck? I know several GM owners that have had to replace the intake manifold gaskets on their vehicles, because they started leaking antifreeze. A mechanic told me it was because the DexCool antifreeze disolves the gaskets.

Does any one know if this is true or just urban legend? And if so has GM done anything to correct the situation.

Just like to get everyone's thoughts on this matter.

lrymal · January 15, 2004

Valid point for older vehicles, but not so with basically the newer body trucks and upwards. I'm guessing about '98 and up.

The gaskets used in the newer vehicles are compatible with Dexcool. Your mechanic is expressing his view because he has probably seen issues with vehicles that are not rated for Dexcool.

If yours is the 2002 model, then you are safe and can enjoy the benefits, provided you keep your coolant level high and not let air mix in by having the coolant too low. Also, make sure you use distilled water. Tap water has unknown minerals and salts which Dexcool is sensitive to.

Regarding the issue with intake manifolds. That problem really raised a stink especially with 3.1 and 3.4 liter V-6s. Not sure how they resolved that. But, it wasn't a fault with the coolant. I had a '99 Pontiac Grand Am with a 3.4 and never had the problem to occur, in spite of the high mileage I put on that little car.

sdtahoe · January 15, 2004

My '95 Tahoe came from the factory with Dex-cool, and now it is at 105K and I have had no coolant problems except a leaky block heater. My opinion on some of the intake gasket problems that GM has had, is it is poor choice of gasket materials not the coolant.

Just had mine flshed when I got the block heater fixed and refilled it with Dex-cool again.

Colorado Kid · January 16, 2004

The intake gasket let go on my '91, and it was (still is) regualrly serviced with conventional coolant, so Dexcool didn't cause it. GM already had the problem with crummy gaskets before they ever started putting in Dexcool.

Engineer · January 17, 2004

I figured that what this mechanic told me was hooey. But since I haven't worked as a mechanic, professionally for 7 years, I got a little out of the loop.

I belive that every thing posted here only reinforced what I suspected, but it never hurts to ask.

My wife's Blazer has 148,000 on it. We have owned it for 4 yrs now. Since I do all of my own servicing I would know if it was loosing coolant. I haven't had to add a drop to it yet.

Thanks for all the replies!!

inscom · January 18, 2004

Howdy all,

my 1997 Silverado 2500 4x4 is also filled with Dex-Cool. Noticed some time ago that the truck is loosing a little coolant. No leaks visible!

Had the coolant changed a few months ago wit DxCool ( I hope so...one never knows) and still loosing a little coolant Wonder wether someone has some advice.

Thanks

BTW, just topped the overflow container...drove abt. 20 miles, and again, the coolant in the overflow container is gone! Still no leaks visible.

CdnChevy · January 19, 2004

As a side note what benefits are in the Dex Cool? vs regular stuff.

inscom · January 19, 2004

CdnChevy...

Not a clue...

MCourson · January 19, 2004

I do know it last longer.

rebel48 · January 19, 2004

My 2001 2500HD owners manual says not to use anything but DexCool antifreze .

Engineer · January 20, 2004

Dex-Cool is supposed to be rated to go 100K before the corrosion inhibitors start to break down. Oddly enough, when I rebuilt the engine in my '90 Suzuki Samurai, Dex-Cool was $1 a gallon cheaper at Wal-Mart than the green stuff was. BTW, the green stuff in my Sammy lasted 174,000 mi, with out ever being changed.

C5pilot · January 20, 2004

whatever coolant you have DO NOT MIX THEM if you mix conventional and Dexcool it will turn to a semisolid jelly that will plug your cooling system! The alleged advantage of Dexcool is extended life 100,000 miles between changes..ED

lrymal · January 20, 2004

Found this quote from some old text clips that I have. I do not have the source.

"Now, you say, "why should I use this stuff?", "....There are some benefits to using Dex-Cool which you do not get when using conventional anti-freeze coolant. Dex-Cool has far superior heat transfer properties than conventional anti-freeze coolant. This alone is helpful in allowing the radiator and fan assemblies to remove heat from the cooling system under engine stress conditions such as towing or very high ambient temperatures. Dex-Cool is also silicate free. Silicate build up in radiators and engine blocks causes engine temperatures to increase due to restricted coolant flow. Dex-Cool should help solve this problem. Additionally, Dex-Cool is kinder to the water pump since it will not have to deal with the silicate issue."

inscom · January 20, 2004

Anybody ever heard of or used engine cooler supplement (sealer)

Eg. GM part # 363462

According to my manual it should help prevent loss of coolant using DexCool that could eat away the intake manifold gaskets!?

MCourson · January 20, 2004

I think all in all DexCool gets a bad wrap. It seems to have been the easy scapegoat for other problems. I have never had or seen a problem that was truley DIRECTLY related to DexCool. I even run it in the '57 with no problems.