Dex-Cool

I just recently had my heater core replaced. The dealer flushed the coolant system and filled it with Dex-Cool (the red stuff). He also mentioned that I had a coolant leak. My blazer is in the shop right now, but I'll get more details tomorrow. I've heard that Dex-Cool can cause problems, check link.

http://www.geocities.com/b_gillie/dexcool_problems.html

Should flush the Dex-Cool? Is anyone else having problems?

Thanks.

I have a '96 blazer, and also had problems with the factory "dex-cool".
It reacts with aluminum, my water pump, radiator and the hoses had to be replaced, the dex-cool forms a sludge like substance (rust color). The dealer put the same stuff back in it, and they didnt do a good job of cleaning out the system.

I took the truck home flushed out the whole system, got rid of the dex-cool, and used regular anti-freeze. Since than I have not had any problems. I WOULD STRONGLY RECOMEND NOT TO USE DEX-COOL.

I USED TO WORK AT A DEALERSHIP, AND A LOT OF CAR AND TRUCKS THAT HAD THE DEX-COOL AHD A LOT OF PROBLEMS WITH THE COOLING SYSTEM. I DONT KNOW WHY "GM" STILL USES THIS STUFF.

jaabou

You state that the dexcool reacts with the metal! Can you be sure its the dexcool? Could it be the water? Could it be the trash in the water mixing with the dexcool? And since you keep saying its the dexcool! Who makes the dexcool? Not GM why you blaming GM then? Shouldn't you be blaming Texaco??? GM did not invent dexcool! Yes I agree their is a problem with dexcool, I have fought this problem many times.

The last thing I heard on the dexcool problem was caused by running the coolant low in the rad which kept the coolant hotter than normal!

Once you have this sludge buildup do you know how hard it is for us mechanics to get rid of it!! Do you know that one flush is impossible to rid the enfgine totally of sludge!!

Here is another thing to ponder over!! The 4.3 L engine is the only GM engine to have this problem! Why is this? Does GM use different metals in this engine than the other GM engines without this problem? I think not!!

I'm not sure that the problem is limited to the 4.3 L. If you follow the guest book pages at the bottom of the link I provided above you will find others. Just an example:

Name : William Goode
Email : wjgoode@wjgoodecorp.com
Year, Make, Model & Issues : 1999 3.1 liter Chevrolet Lumina with brown sludge in coolant expansion tank and also in the filler neck of the radiator.Only 43,000 miles on this car. Any body else have the same problem???

I do agree with your point about a low coolant level being part of the problem, but why are there so many complaits about dex cool. I haven't heard any complaits of sludge build up using other brands. I think I'm going to flush my system anyway and use something else. The more I read on the topic the more I figure it's just easier to play it safe.:smile:

There are different types of sludge! The 4.3L are the ones that clog things up. The lumina you quoted is the sealant pellets GM puts in the engines to prevent leaks! If you look closely at the sludge in both examples you would see a difference. GM now has a recall on 2000 to 20002 3.8L engines, part of the recall is to put the sealant tabs into the rad. GM is adding language that informs the customer of a residue that will show up in the overflow and rad cap! It is not abnormal unlike the 4.3L problem.

Here's a good question for you see if you know the answer!!

What clogs up a radiator and leaks out of the smallest holes?

Regaurdless of there being different types of sludge, I should not have a product being put in my truck that has a tendency to readily turn to sludge. Last time I checked sludge does not transfer heat well. Like Jaboou, I am not blaming GM for making the stuff, but I am blaming them for continuing to use a faulty product. I am not going to wait for a possible recall to fix the problem, by then my truck will be trashed. I was just curious about other peoples' experience with Dex-Cool and I hope anyone else reading this will be warned.

Some of your information seems helpful, but you sure like to challenge people.

Your talking about air.

Later.

I am not trying to challenge people but I am trying to educate people! The more you know the less you will be taken advantage off!! I am here of my own free will I do not get paid to post here! I am here to help people understand their problems and fix them if I come off wrong then I am sorry!


The answer to my question is Dexcool! It clogs a rad solid yet it will leak out of any holes it can find.




but you sure like to challenge people.

Your talking about air.

Later. [/B]

I am having the same problems with my Blazer heater core, and other engine cooling devices. I've joined a classaction lawsuit against GM at www.bigclassaction.com. I suggest that everyone with these problems do the same. If you wait 150,000 miles before having any maintainance on your cooling system, you will likely be out thousands of dollars on repairs!

Have on 01 Blazer that just started leaking coolant into crankcase at 12K miles. Took to dealer that sold me the vehicle and has done all the service to date. After explaining the problem they took the Blazer back to garage for few minutes and said, "no problem found". I'm assuming they maybe (hopefully) tighteded the intake and added some stop leak, or maybe they did nothing. Told me if it continued leakiing to take to a nearby dealer and have them add coolant. Whew, what a mess this is. Pretty bad when the selling dealer throws you out and leaves you holding the bag with a serious problem. For now I'll monitor the coolant and if leak continues I suppose I'll have to find a mechanic to replace the gaskets and coolant. Sure not going to ruin an otherwise perfect running factory matched and balanced drivetrain. From what I understand the Dexcool attacks the plastic manifold gaskets when under repeated heat/cool cycles as in short trip driving which is what we do with this.

Should I or could I just drain the system and put regular antifreeze in it. Or should I have the whole system flushed and then put in the regular antifreeze.

I haven't had any problems yet with my 1996 Blazer with 57,000 miles but I don't want to take the chance.

What I've read the best thing would be to run a cleaner through the system, drain and flush, then maybe add Prestone Extended Life antifreeze. This is a new product similiar to Dexcool but improved. Be sure to mix exactly 50 -50 with clean water, maybe distilled water. Best water I've found is out of the dehumidifier or central AC when running. No minerals at all.

Hey All, I drive a 98 blazer,recently purchased with 59k on it. The coolant resivoir was rusty so I flushed and filled with prestone dex cool. My wife drives a 96 caprice, all of a sudden she had no heat, clogged heater core!!! Flushed, flushed again and used cleaner,flushed and filled with prestone dex cool. NO MORE PROBLEM!!!!! The only problem with dex cool is that it does not last 5years/150k. If you flush and refill every year or every 2 years, like you should with regular coolant you won't have a problem!!!!!! As for flushing and refilling with regular coolant in a system that used dex cool,it is almost impossible to remove all traces of dex cool. If you think you have problems with dex cool, wait till the regular coolant and dexcool mix, not good, turns to like jelly. being an ASE Certified tech I have seen this,it's ugly!!!!!!!!! Bottom line is flush and refill with dexcool once a year and you'll be good to go!!!!!!!!!!!

Oh I forgot, if you don't service a system with regular coolant, the same thing will happen that happens with dexcool.

Hey All, I drive a 98 blazer,recently purchased with 59k on it. The coolant resivoir was rusty so I flushed and filled with prestone dex cool. My wife drives a 96 caprice, all of a sudden she had no heat, clogged heater core!!! Flushed, flushed again and used cleaner,flushed and filled with prestone dex cool. NO MORE PROBLEM!!!!! The only problem with dex cool is that it does not last 5years/150k. If you flush and refill every year or every 2 years, like you should with regular coolant you won't have a problem!!!!!! As for flushing and refilling with regular coolant in a system that used dex cool,it is almost impossible to remove all traces of dex cool. If you think you have problems with dex cool, wait till the regular coolant and dexcool mix, not good, turns to like jelly. being an ASE Certified tech I have seen this,it's ugly!!!!!!!!! Bottom line is flush and refill with dexcool once a year and you'll be good to go!!!!!!!!!!!

Glenn did you use Prestone Extended Life or does prestone make a dex cool?

I used Prestone Extended Life, Dex Cool Aproved!!!!! Silver bottle with orange cap!!!

its not the metal that dex cool reacts with. its any traces of standard (green) coolant that create a problem. see, when dexcool and standard coolant mix, they form an acidic formula, thus eating at all your metals, etc. that is why it is imperative to have your system flushed in its entirety before switching from one to another.

matt

Good grief! Ive been wanting to sell my 79 el camino, and get me a newer gm product, but this dex-cool thing is worrying me a whole lot.

I was looking into getting either a s-10 blazer, or c/k 1500 fullsize. Probably 90-98 models on ck1500 and 94-98 on blazers.

Robert

Hey All, I drive a 98 blazer,recently purchased with 59k on it. The coolant resivoir was rusty so I flushed and filled with prestone dex cool. My wife drives a 96 caprice, all of a sudden she had no heat, clogged heater core!!! Flushed, flushed again and used cleaner,flushed and filled with prestone dex cool. NO MORE PROBLEM!!!!! The only problem with dex cool is that it does not last 5years/150k. If you flush and refill every year or every 2 years, like you should with regular coolant you won't have a problem!!!!!! As for flushing and refilling with regular coolant in a system that used dex cool,it is almost impossible to remove all traces of dex cool. If you think you have problems with dex cool, wait till the regular coolant and dexcool mix, not good, turns to like jelly. being an ASE Certified tech I have seen this,it's ugly!!!!!!!!! Bottom line is flush and refill with dexcool once a year and you'll be good to go!!!!!!!!!!!

Glen, thanks for the info. We too have a 98 Blazer with junk in the radiator. Can I flush it out myself?

You can. I flushed twice with water,then filled with prestone flush and coolant(follow the directions).I flushed again with water, then filled the system 50/50 use DISTILLED water. I'm going to repeate the whole process again, cause I know its still not clean. I LOVE MY GM PRODUCT, even with their problems!