Mixing coolant

[Wayne County Hose]

Big discussion in work. Can you mix the green and red coolants with no ill effects? Counting on my TBN brothers here. ;-) BTW, I don't have a horse in this race.

 

[sam5570]

as far as i know yes you can mix red and green i have done it for years after all it is antifreeze no matter the color the red has brought up some intresting discussions @ some swap meets some very well known engineers say the only reason they made it red was they warrented it for a long period of time and it wouldd hide the corosion or rust.

 

[crashz]

Depends onthe red and the green. Fieldservicengineer is an expert in this, so I hope he weighs in on this thread. I'll give you my understanding below:

Typical green coolant is glycol based. What is usually refered to as red is a long life oraganic acid based coolant (think Dex-cool). When red coolant came out, it was not at all compatible with glycol coolant as far as I understand. GM replacement Dex-cool currently does not recommend mixing coolant types. Last year I replaced the Dex-cool in my 2004 GMC and the replacement coolant (Prestone I think) specifically warned against it. I have no idea what the effects are if you mix the two. I have heard that it will cause solid particles to form and fall out of suspension, clogging passage ways and tubes. But I have not mixed them, so I don't know for sure.

Now there are long life coolants that supposedly mix with everthing (other Prestone products), however I have not used them. Its actually been a while since I've seen name brand glycol only coolants.

 

[bkc]

When I was working in a shop back when dex cool came out, we were all told the same thing. Dont mix extended life with the green stuff, but no one could tell us why.......

We decided to do an experiment. We pulled some dexcool and some standard green coolant mixed them in a clear jar and left them on the shelf. After months and months nothing happed. We put broken pieces of aluminum casting from a smashed water pump, we added cast iron pieces, steel chunks, even put part of those gm plastic /rubber intake gasket.......anything we colud think of to try and get this bad thing to happen by mixing coolant. We even heated up the coolant mix ( minus metal) in the micro wave to boiling point. Nothing ever happened, no solids, no cloudyness, nothing exploded...haha

I never understood why it was "bad" to mix them, But in our redneck testing found nothing out of the ordinary by mixing them. It wasnt long after that, they came out with coolant good for all makes and modles, so we gave up.


My limited and maybe worthless 2cents
Brian

 

[dmccarty]

It depends on the what is the Red and Green coolant.

My F350 had gold/yellow coolant from the factory. When it was time to change the coolant in the truck, I put in JD coolant which I think was green. The chemistry was the same, only the color was different. I don't think you were supposed to mix the Ford green and Ford gold/yellow colored coolants.

Sad thing is that I just changed the coolant in the JD and the F350 and I cannot remember the color. The overflow tank in the truck has looks yellow. Guess I need to look in the jug the coolant was shipped. The JD coolant I used for years was Cool-Gard I and now it is Cool-Gard II.

Later,
Dan

 

[ramoffroader]

I work on big trucks and working with engine maunfactures have learned a few things on this. First yes you can mix the green with most of the reds. When you do this you basicly loose the advantages of long life coolant. When you are done mixing them, the coolant properties are that of the green. Meaning you need to replace it every couple of years as the rust inhibators, etc. break down. Dont mix the two thinking that you are extending the life of the green. Not that most of you worry about it but the engine manufactures are real particular about what you put in there engines. They want the coolant to have the proper additive package they feel their engine's require. This is real important when dealing with diesel engines with wet liners. It can cause warranty issues. GM is a stickler on Dexcool and Ford is the same with there gold colored antifreeze. Hope this info helps.

 

[Canada_CT230]

The wife has G12 coolant in her VW Jetta. I hate that thing but that is another story. You can NOT mix that stuff or it will gel up and make a gooey mess.

I changed the thermostat in her car a while ago and I had to catch, filter and re-use everything I could. That stuff is worth more than gold at $40 per 1 litre.

There is a ton of chemistry in coolant. I don't think metal is the only concern. There are plastic engine parts, gaskets, rubber and other stuff that can be affected. I don't believe all the manufacturer hype on a lot of things but in these cases do you have the long term confidence to put another coolant in there and to know all the material compatibilities?

Food (or coolant) for thought.

 

[jonyyuma]

Same here, was told by Toyota Dealer not to mix any thing with red coolant..I have seen thick gooey base run out of older prestone coolant that i has stored unused in the jug.I liked Peak or Texaco for replacement on my diesels. Prestone yellow did plug up the GM radiator, enough for a rod-out job. Was told then it was due to Silicone Content..

 

[vornez]

NEVER mix red and yellow coolant. In particular avoid the yellow supermarket coolants, they often state they are glycol free. Mixing green with red is acceptable, they are both glycol based, mixing red with yellow turns the mixture into a glue, with particles 2-4mm in diameter that clog up the fins of the radiator. Cooling systems have no filtration systems, even if they did, the filter would be clogged. Red and yellow will destroy your radiator, your pre-heater, the cabin heater and some types of coolant sensors. Using glue as an engine coolant is the best way to destroy a functional cooling system and put the engine at risk.

 

[Midniteoyl]

Sorry, cant go by color anymore..

 

[kenmac]

Sorry, cant go by color anymore..

Sure can't. I put red food coloring in my coolant so, I can see it in the tank

 

[Midniteoyl]

LOL.. I've got Green Dye..

 

[workinallthetime]

just dont take the chance, i was in the shop when gm switched from green to dexcrap, the early years saw all kinds of problems. thye even told us to use distilled water not tap water with dexcool. i can not count the grand am's, firebirds, and grand prix's ive seen with a muddy looking substance in the coolant resivor. i do think dex cool is a good product and have it in all my gm's but i think they made it into something you have to think about instead of just dumping what ever out of the barn into the system.
short story time....
we had a 7500 series kodiac dump truck that was eating up heater cores, the shop i worked at decided to go cheep and buy a "dex cool look alike" we had been using it for a couple years with no issues that we knew about until this kodiac. after the 3rd heater core i flushed the system and put real dex cool back in it. we saw the truck for all their maintence and never had another failure. Bad thing is how many other cars/trucks got jacked up on that coolant.
take into consideration what the coolant is doing, it not only helps cool the engine, it lubricates the water pump to some degree, and prevents electrolosis.
good luck, some things are not worth saving a couple bucks on

 

[Cpjlube]

From my experience Dex Cool worked well. Until the cooling system was allowed to get low. Most early Dex Cool Gms had an unpressurized overflow. So some evaporation occurred. When the actual cooling system went low, that's when I saw the coolant tend to gel up.
And as a side note. I was in a GMC dealership last month. On the TV in the service center they had a service recommendation for GMC pickup radiator service. 3years or 30,000 miles. I said to one of the service writers. " Hey, I thought the coolant was good for 5 years or 150,000 miles." He laughed and said "yeah, we found out that was a bad idea." Apparently the caveat is "or until dirty". Lol

Chuck

 

[Midniteoyl]

Dexcool like head gaskets...

 

[Cpjlube]

Dexcool like head gaskets...

If I was going to blame Dex Cool for anything, I would say Intake manifold gaskets. Ask any 3.4 liter owner.
Or should I say litre. Sorry. Old Trans Am thing.

Chuck

 

[workinallthetime]

If I was going to blame Dex Cool for anything, I would say Intake manifold gaskets. Ask any 3.4 liter owner.
Or should I say litre. Sorry. Old Trans Am thing.

Chuck

3.4 was a grown up 3.1 which grew up from a 2.8. alll had horrible intake manifold issues, nothing to do with dexcool. think i did over 100 of them in 6 months one year

 

[CJONE]

I have changed enough intake gaskets AND intake manifolds on 5.7's AND 3.8l both for customers and my personal vehicles. The only thing they had in common was Dexcool. When I buy a GM the first thing I do is flush the system and put green back in. If it was new I would let it run a few years then switch but used it gets flushed as soon as I get it. Just picked up a like new 02 buick with 50k on it and has to use a pressure washer to blow the brown sludge off the surge tank walls. Not a Dexcool fan. CJ

 

[oldyellr]

You're right, CJONE, the problem only reared its ugly head after the introduction of Dexcool. Of course, the manufacturers will tell you Dexcool is less toxic and more environmentally friendly and specially formulated for modern engines.

 

[CJONE]

You're right, CJONE, the problem only reared its ugly head after the introduction of Dexcool. Of course, the manufacturers will tell you Dexcool is less toxic and more environmentally friendly and specially formulated for modern engines.

He HE he, specially formulated to bring the MFG more $$$ in repair parts!! CJ