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DEXCOOL

102K views 42 replies 38 participants last post by  Tomko 
#1 ·
I keep hearing more and more complaints about dexcool,every mechanic i know has said they have had GM cars in their shops with cooling problems.From clogged radiator to bad freeze out plugs to clogged heater cores and all on fairly low mileage cars.From what i can figure out this stuff is garbage.I checked the radiator in my 99 regal gs and found scale under the cap and white corrosion in my radiator my car only has 30000 miles on it.My advice to any one with dexcool in their car is to get it serviced and do it often or you will have problems.
 
#27 ·
chev454ls said:
You also can't mix the Dexcool with the normal red stuff because it will basically gell up.
And tap water will give you a little meltdown.

Other than not mixing well with pretty much anything, I havn't had a problem with my coolant system on any GM truck so far....knock on wood. The owner's manual said 100000 miles before messing with it, so I am going with that.
 
#28 ·
Should also be noted that when you buy Delco Dexcool (the OEM coolant), it is not pre-mixed, unlike the Prestone Dexcool, which is pre-mixed. So, if you top off or you flush and fill the system and use Delco Dexcool make sure you do half and half using preferably distilled water instead of tap water.
 
#29 · (Edited)
Every time I have my car serviced where they have to add coolant they always add the green stuff to it. I've taken my car back to several shops and made them fully flush and refill the coolant with DEXCOOL because they mixed the 2. So far this has happened 3 times at 3 different shops. I even told them at the third place to remember it takes DEXCOOL, you know the orange stuff, and I got it back with green. And I always use distilled water when I add to it to prevent hard water deposits from building up which can also contribute to clogging issues.

Actually my car is being worked on again and they had to drain the coolant... here's hoping I don't get it back with green coolant in it, tho at least if I do the block and radiator was fully flushed so there won't be any mixing, just the wrong stuff...

Also check the underside of your radiator cap and if your cars overflow tank has a dipstick (like mine does) check it for any hints of slime or sludge. The sludge tends to be light colored, kind of whitish orange.

Also dexcool doesn't like air in the system so be sure to check the level frequently. It doesn't coat surfaces like the green stuff does so any surfaces exposed to air are more prone to rust.
 
#30 · (Edited)
Bret said:
Our business has an '02 Buick Lesabre as one of our company cars. It has just over 37k miles on it and was purchased in June of '02. Here is a sample of the "dex-cool" fluid that I took out of the reservoir:
http://gallery.s2ki.com/imagecatalog/imageview/124861
From my reading about the problem at several sites on the internet and reading a GM TSB, I have found that GM wants to point the finger of blame at consumers for operating the car with a low coolant level for an extended period of time.

GM's pathetic response to this problem, mostly blaming the consumer and denying that there is a problem with dex-cool, is completely unacceptable. Making consumers pay for repairs because their product does not perform as they claim it will is a sure way to create badwill. There is a class action lawsuit that has been filed. While I generally can't stand trial lawyers, I hope that in this case they take GM to task and get them to pay for every repair that is a result of this design defect.

BTW, we also have an '00 Lesabre that has 79k miles on it. The coolant in it is also brown, but not quite as bad. Our GMC truck and the president's Cadillac show no contamination.
Wow, glad I read this. Just went to check my rad, the radiator cap has some brown crud on it and the downtube also has some rusty looking crap in it. I've been thinking of radiator maint, and I will be taking it in this week for the jobbie.
I have 27,000 miles, the car is probably about 3 years old, purchased Dec. 2004. Still under warranty.

For manufacturers to act this way after all their previous blame-the-customer disasters is just totally unacceptable. I guess GM learned nothing from its experience with Ralph Nader. Or should I say experiences.
I'll check with the Public Citizen site to see if Nader is part of this lawsuit. That would be justice, hahahaha.

It's like Chrysler's 2.7 junker that should have been put out to pasture years ago and replaced by the 3.2 as base V6 engine.

What in hell is the matter with these people? Think they're in Congress or something? :fall:

Link does not work, BTW.

Thanks for the heads up, Bret.
 
#31 ·
I for one have never had an issue with Dexcool, but I replace my coolant on a preventive maintenance schedule as if it was old school green stuff. And I'm also religious to keep the mixture 50/50.

I've read all of the horror stories and I'm nervous but so far no cooling issues.

I think one of the main issue with Dexcool is that people take the "long life" marketing to mean "lasts forever". This stuff only lasts twice as long as the green stuff and you're supposed to replace the green stuff every other year. If you are on your 5th year on the orange thats too long in my book.

If anything Decol encourages people to neglect their coolant... With all alloy or mixed metal motors this is a receipt for disaster regardless of what color the coolant is.
 
#32 ·
2002 Caddy said:
I for one have never had an issue with Dexcool, but I replace my coolant on a preventive maintenance schedule as if it was old school green stuff. And I'm also religious to keep the mixture 50/50.

I've read all of the horror stories and I'm nervous but so far no cooling issues.

I think one of the main issue with Dexcool is that people take the "long life" marketing to mean "lasts forever". This stuff only lasts twice as long as the green stuff and you're supposed to replace the green stuff every other year. If you are on your 5th year on the orange thats too long in my book.

If anything Decol encourages people to neglect their coolant... With all alloy or mixed metal motors this is a receipt for disaster regardless of what color the coolant is.
I am pretty certain that it's suppose to last 100,000 miles under normal conditions between flushes.

I think that is in my owner's manual somewhere...but maybe it's not all GM products.
 
#33 · (Edited)
member12 said:
I am pretty certain that it's suppose to last 100,000 miles under normal conditions between flushes.
That is exactly my point and the main problem with dexcool.

We hear it all the time on some of the Caddy forums I'm a member of:
I have a 10 year old car with about 50,000 miles and my radiator is leaking, my heater core is plugged or my head gaskets are toast, etc etc...

Have I changed my coolant?

Of course not, Dexcool is good for 100,000+ miles
Here is what the owners manual says
The cooling system in your vehicle is filled with DEX-COOL® engine coolant. This coolant is designed to remain in your vehicle for five years or 150,000 miles (240 000 km), whichever occurs first, if you add only DEX-COOL® extended life coolant.
I draw your attention to the part about five years and the "comes first part"

The MOST critical part of coolant maintenance is TIME not distance. The longer the coolant is in contact with the aluminum and iron parts the more "sour" it gets and the more damage will occur...

My advice, If you have a cast iron block (e.g. 3.8L) change dexcool at 4 years. If you have an aluminum block (LS1, Northstar, etc) 3 years is all that I would go.

Don't believe me? Google "Northstar and Headgaskets" and read the carnage that results when you fail to follow the Dexcool servicing as GM recommends. Coolant is cheap and easy to change, head gaskets, radiators, water pumps, heater cores are neither cheap nor easy.
 
#35 ·
Finally went ahead and flushed it and put in fresh dexcool (dealer was running a special on the flush/fill that I couldn't turn down). It was starting to look a little suspect (at 30K/3 yrs--maybe 4 since it was actually built). Looks a lot better now. I think the rule that I would go by from everything I've read is that any coolant you want to use (that meets the proper specs) is probably ok, but periodic changes of coolant are definitely important, regardless of how many miles it's "recommended" to be able to take. If it's starting to look suspect, don't be cheap and just get it taken care of (or you'll pay more later). :p
 
#36 ·
I changed out the thermostat in my 2003 Trailblazer with an inline 6. Mileage at this point was 111,000 miles.
At 47,000 miles, the water pump was replaced. Some dexcool was drained. and refilled at that time.
I see no sign of gunk... I can still see the design of the styrofoam casting-
 
#37 ·
yep thats dexcool for yah montguy. I belive GM issued either a recall or service bulletin for dexcool. The stuff is basically garbage because of its frequent habit of hardening and its knack for corroding radiators. Also Dexcool cannot be mixed with tap water (its not pretty). however most of the hardening problems come from people that do not mix the dexcool right. If you want to save some money and a ton of hassle do not use dexcool
 
#38 ·
GMfan1111 said:
yep thats dexcool for yah montguy. I belive GM issued either a recall or service bulletin for dexcool. The stuff is basically garbage because of its frequent habit of hardening and its knack for corroding radiators. Also Dexcool cannot be mixed with tap water (its not pretty). however most of the hardening problems come from people that do not mix the dexcool right. If you want to save some money and a ton of hassle do not use dexcool
Been using Dex and mixing with tap since 1996. No sludge or gunk and no engine problems from the cooling system. I will continue to do so. Most problems from dex is from a non sealed system. Dex does not like air too much. If your system is not set as it should be, you will have problems. But that is not from dex, if from a badly maintained system.
 
#39 ·
I said in my post that while DEX does have a tendency to harden and react badly with just about anything mixed with it most of these incidents are from idiots that don't mix it right or outside contamination of the dexcool. I use another brand of coolant besides dexcool because i don't want to take a chance with the DEX reacting.
 
#40 ·
when i do a flush, i use either 1 of 2 types of stuff, Pro-tec makes a nice radiator flush, get a flush and conditioner, and prestone makes nice flush,

i normally do normal flushes with pro-tec and do back flushes with the prestone stuff.

dex-cool vehicles get dex-cool put back in them, pre-mixed 50-50 mixture.
we get it in bulk. 200 gallons at a time.
 
#41 ·
The only time I have seen gelling in a cooling system that had Dexcool in it was when other additives were added to the system.
You CAN mix Dexcool with regular anti freeze, but why would you, you will take a 5 year 100,00 mile anti freeze and reduce its useful time down to that of the regular anti freeze.
I have used it in all 9 of my cars for over 15 years and not had a single problem.
All the pictures you see of sludge is not the dexcool, it is STOP LEAK someone put in the system.
The key is to clean and flush your system before you use Dexcool, use distilled water or a low mineral water.

Even better, use EVANS coolant, it is guaranteed to last the life of your engine. NEVER has to be replace and you will have "ZERO" rust and corrosion because you do not add water. You use it full strength. It cost $40 a gallon but just like synthetic oils it WILL save you money and time and parts down the road.
I have flushed and use Evans Prep( which removes any remaining water after you drain your system) before filling with Evans Coolant. Large trucking companies and government vehicles use Evans because it is that good.
It's been around for years, so it's not some new gimmick to make you spend your hard earned money.

IT WORK, PERIOD
 
#43 ·
But some 59 year-old guy pulls a Lazarus to shill for something no OEM recommends.

I miss the old days when you could go to a bar and get solid advice like this and not have to wait a decade for it.

Now where is that thanks button?
 
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