Should I change out my anti freeze?



You can google dexcool sludge, and find enough links but a green global coolant is not wrong.


Been there, done that. It is amusing. I read that Elvis was spotted draining Dex-Cool from his Cadillac!


Are you saying global green is wrong? I read Elvis died in 77 and dexcool was not introduced until the 90’s, any other fake news you wish to share? PS I saw Elvis in Carbondale Oct, 76, I was at college at SIU, part of the set up crew, and got to stay and watch the concert for free, it was $26 a ticket as I recall, got pics also, posted on some elvis website somewhere. here they are!


My car has the Toyota super long life pink fluid that only comes premixed at $26 a gallon and is said in the owners manual to be good for 10 years. At that time I will flush it and use a universal 5 year fluid.

I have been driving since 1952 and in all that time I have encountered one failed thermostat. This includes all the cars of my children, grandchildren and in-laws.

I think most thermostats are changed to try to fix either overheating or low or no heat problems, not because the thermostat has actually failed.


You must be living a charmed life there OT; I must have changed out a half-dozen or so failed thermostats in various vehicles of mine over the years.


I had to change my thermostat, running maybe 10 degrees too cool, setting off a cel. The thermostat with housing, not sold separately was $65, had to pull a wheel and and alternator to change it, would not have done it if I did not have to,


Oh for the good old days. I used to change coolant and thermostats every year. Just as a matter of maintenance.


What exactly do you consider a failed thermostat?

I consider a thermostat stuck open, leading to P0125 or P0128, check engine light, failed smog inspection, etc. a failed thermostat


Basically I am having the local car repair place where I take all my work do the work on this, as I am also getting the air filter and cabin filter replaced and having new windshield wipers put on. Yes I am paying someone to do those other items because I don’t like hassling with them and it’s worth the little extra costs to have them do it.

Back in the day when I was young and a go getter I would chance out my own antifreeze, and all I would do is drain, put a hose in and let it run, start the car and let it run with the water in it for a while, shut the car off and let it cool redrain and fill with new fluid. My question is in today’s way, anyone know what they will do and will it be much different then what I use to do.


Yes, I’ll say it. That coolant is the WRONG coolant for vehicles that were manufactured by a company that specifies Dex-Cool.

That green coolant is the RIGHT coolant for my Dodge Caravan, though. The manufacturer specifies it.

See that little Grand Prix photo in my post? I could put green coolant in it. I could put Autolite spark plugs in it. I could put 10w40 oil in it and probably have it run. I’ll bet I could run with Dex/Merc transmission fluid instead of the right DexronVI fluid, but how well and for how long? Experiment and who knows?

However, when I purchase used cars, as I did when I bought the Grand Prix, I check to see how the vehicle was maintained by checking records and fluids, etcetera. I have never hired a mechanic to do my checking.

If that Grand Prix had green coolant in it I would have walked. That would be a deal killer to me. I’d have to wonder why somebody would not maintain the vehicle according to the manufacturer, who did it, and what other surprises await me should I choose to purchase the car. :wink:

I own all the books for my cars. I have a ten pound set of GM services manuals for that specific Grand Prix. I have the Owner’s Manual, too. I go by the book(s).

Elvis? I made up the part about the Dex-Cool. I have no idea what type of coolant he uses or where he gets it. :smile:


“About the only ways I know of to screw up Dex-Cool is to never change it or to mix green coolant with it”.

If a simple drain and fill was performed replacing Dex-Cool with green coolant aren’t they already mixed to some extent?




Here’s what GM says,

Mixing conventional green coolant with DEX-COOL® will degrade the service interval from
5yrs./150,000 miles to 2yrs./30,000 miles (50,000 km) if left in the contaminated condition. If
contamination occurs, the cooling system must be flushed twice immediately and re-filled with a
50/50 mixture of DEX-COOL® and clean water in order to preserve the enhanced properties and
extended service interval of DEX-COOL®."


That’s basically how I do it on both my vehicles; but mine are both 25+ years vintage. Some folks here believe running w/plain water even for a half hour can damage aluminum components of the engine, but I’ve never had any problem w/that myself. Of course the only proper way to do it is how the factory service manual says, and using what it says for the coolant.


Well water might damage aluminum if it is too acidic or alkaline, but city water is treated to fix that issue. City water should also have reasonable levels of dissolved minerals, also a possible problem with well water.


From previous on this site,
TriedaqJul '13
I owned a 2006 Chevrolet Uplander which, on the recommendation of my independent garage, had the radiator flushed and the Dex Cool replaced with universal coolant. That was three years ago in 2010. My son now owns the Uplander and there has been no problem with the universal coolant.


TesterJul '13
When possible always get rid of the Dexcool and use one of the universal antifreezes.


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ok4450Jul '13
The Dex Cool would be gone if the vehicle was mine. For what it’s worth, the 96 Camaro that my oldest son owns uses Dex Cool and that car went through 3 water pumps (counting the original) in about 4 or 5 years time not to mention the sludging problems.

On the last pump replacement I flushed it out, replaced with green, and never a problem since.
That’s going on 8 years now…


missilemanJul '13
I would never own a vehicle with Dex-Cool flowing through it’s engine. I always flush it out and replace it with the tried and true green stuff. Never had a problem in all the years I have done it.

Not just green stuff but global or universal is the important point. @common_sense_answer

Of course it was 100k miles ago I switched to peak global, still waiting for an issue.


@Barkydog. More than four years after the post made in July 2013, the 2006 Uplander is still running well with over 200,000 on the odometer and my son is using universal coolant in the radiator. He has had no cooling system problems and there has never been a problem with the intake manifold gasket.
It would probably have done just as well on Dex-Cool. My guess is that as long as the antifreeze types aren’t mixed, it probably doesn’t make any difference which is used.
I liked the good old days of the 1950s where most of the antifreeze was either Prestone or Dupont’s Zerex. We had cast iron engine blocks back then so we didn’t have to worry about the aluminium block engines requiring a special type of coolant. I also remember Dupont’s Telar antifreeze of the late 1950s and early 1960s that would change color from red to yellow when its rust inhibitors were depleted.


Yeah I think it was about $2 a gallon back then too. Don’t remember exactly when but was a little shocked when it hit $10.


After replacing the intake manifold gaskets on my sons Pontiac I drained and rinsed the mysterious green coolant from the cooling system that the previous owner put in. I put in Dex-Cool compatible coolant from O’Reille’s auto parts.