[drptop70ss]

Anyone know for certain? I have heard yes and no. I have had it with this orange crap, it has made a mess of my 96 blazer's cooling system since new. Latest is now the intake manifold gaskets are leaking so I get to tear that apart. Already replaced the heater core and had the system acid flushed years ago but chevy wouldnt put the green in there for me. I am going to replace the radiator now also so figure this would be the time to switch. Can I just run water through the system a few times and drain out the orange and replace with green or will it really plug up the system? I need the truth, not rumors. [img]smile.gif[/img]

[pmullaly]

I too ran into the problems with the Orange crap in my 96 Impala. Go to the dealer where you had the flush done and purchase the prestone acid flush that the dealer uses. Use it per the directions,replace the cap and T stat, refill system with the green and bleed.
You'll be good to go.

The Prestone flush is a powder and comes in a 2 part can one side acid the other neutralizer

[ejrempel]

I just bought the Canadian Tire equivilent of Dexcool for my 'vette {alum. rad}. Are you saying it is no good? That I should stay with a Prestone-like product that is alum compatible. Talk to me.

[drptop70ss]

ejrempel,
just search the net for "dexcool" and see what kind of stuff comes up...I am not the only one that has had their system wrecked by this stuff. .

[DjD]

I've gotten conflicting info on Dexcool. First the problems, then the info.

1> The '96 SS Z28 got a plugged heater core (no heat). I used the Prestone Flush (per the directions) and the heater started working again. A couple days later the heat stopped so I pulled the hoses at the firewall and just flushed the heater core. Heater worked for about 2 weeks this time.

2> The wife's '00 Impala's low coolant warning sensor started regestering low fluid even though the system was full. Cause was oil change place added green to the red Dexcool causing the Dexcool to jell and coat the inside of the radiator. Then a bad radiator cap released so much pressure it over flowed out of the overflow tank and shortly after the wife overheated (bells chiming and flashing red light on dash). That caused the intake gasket to go!! All this over a period of 3 months and just past the warantee...

Doing some web research on ls1 and lt1 sites (Vette, Camaro and Impala) I find the heater core and the jelling of dexcool when mixed are common problems. Also find that most believe the green antifreeze is too harsh on alum parts and the Dexcool was designed for use with alum.

Then I talked with a service writer at the dealership. He said they see a lot of plugged heater cores and they do the flush about 6 times before getting good results and heater cores that don't plug any further. He didn't feel it would be a problem to replace the Dexcool with the green stuff...

I question at what point do you feel good that you've flushed enough to have gotten all that red goop coating the inside of the rad and block cleaned out so it doesn't interact with the green if switching. Prestone makes their own red stuff (Dexcool Approved on the lable) and I'm going to use that now and will be flushing both cars several times.

[Importtech]

Flush your system real good and get rid of the dexcool. All its good for is mud in your radiator.
I expect any of those silicate type of coolants regardless of the brand to have similar results.
Go back to the old green coolant. I'm surprised the dealer wouldn't flush is out for you. ANY Gm
guy will tell to loose it. Some of our Isuzu pickups had the GM 2.2 with dexcool. They always had the same problem. You do need to do the flush pretty well or mixing it can cause jelling.
I cant tell you how many I've changed over.
On the low coolant level sensor...They stick ALOT. You can pull the subtank and clean it out real good and probably get the sensor to function again.

[Chevello]

Maybe the GM Dexcool is different from the Ford stuff, but I changed out the original orange from my Exploder at 50K miles and replaced it with the Prestone orange stuff. Went another 27K and needed to change a head gasket. Haven't had any other problems in the last 20K.

The wife's GP had the GM dexcool in it and is a victim of the 3.1L intake gasket leak problem (oil leaks all over the engine at 40K miles ). Have'nt done anything but add coolant to it so far. No water in the oil, no oil in the water (so far)

Hoping to find out if there is a revision to the gaskets before I buy a new set and tear the poor thing apart.

K

[Derek69SS]

What year did they start using Dexcool?

I don't have anything new enough, but I want to make sure my Dad knows not to add the green stuff to one of his newer cars.

[Wwalstrom]

The Dex-Cool crap will jell up even without mixing the green stuff in it. Having the "jelly" problem with both my 99 Silverado and my 98 Lumina. Fact is, GM touts the junk as a "5-Year" antifreeze/coolant, BUT the company that "designed" it never intended it to last any longer than 2 years ..... just like antifreeze. If you've got dex-cool in your system, you've got to flush it EVERY TWO YEARS. And, if your vehicle is still under warranty, you've got to put dex-cool back in, or warranty is voided. No GM dealership I have talked to will flush dex-cool and replace with "the green stuff".

[drptop70ss]

Well I did the intake gaskets and converted to green prestone this weekend. Major PITA with all the sensors and related stuff, took a full day to do the gaskets and reassemble. With the intake off I could see the red sludge in the head cooling passages, and this was on a well maintained vehicle. I cleaned up as much as I could before installing the intake. The funny thing is dexcool is said to be made for aluminum parts, my intake actually had corrosion marks on it where the intake gaskets were touching. Luckily the felpro kit had plenty thick rubber edged gaskets which sealed up ok. After that was all done I flushed the system at least 10 times, adding water and then running the truck to full temp, cooling off some and then draining the radiator out. Didnt have a hose handy to power flush as my outside hose hookup cracked and its still on the "to do" list to fix. I probably will never get all the orange out but I believe I got most of it out by the color of the water I was draining from the radiator. Before adding the green I mixed the orange and green in a bucket to see if they would gell or react, they mixed together fine as I should of expected as they are both ethylene glycol based. I then added the green to the truck and drove it all day with the A/C cranking, never saw temps over 200 degrees so everything looks good. Heat cranks out right away where before the truck had to get well over 100 degrees to give heat. I will probably drain and refill the radiator a few more times before winter but no more dexcool for me. Thanks to those who emailed me and said it could be done, a little reassurance goes a long way..I finally decided the green couldnt do anything worse to the truck than the dexcool already was.

[LS6 PWR]

i shouldn't be opening my big mouth so fast but...my grandparents have a 96Tahoe with the red stuff in it...has 110,000 miles...was changed at 46,000..thatw as it...never hits 200....my dad has 2 2000 GMC C-8500 ten wheel dumps...they both have the dexcool..they both run 200-210...depending on the load the truck is pulling...

[Norm_N_Tam]

Originally Posted by ejrempel

I just bought the Canadian Tire equivilent of Dexcool for my 'vette {alum. rad}. Are you saying it is no good? That I should stay with a Prestone-like product that is alum compatible. Talk to me.

Yes, you can replace Dexcool with Prestone in the yellow bottle. There is very little difference between the two, besides the color (Prestone is greenish yellow). Prestone 'Low-Tox' is another story (green color). Low-Tox contains propylene glycol rather than ethylene glycol. Both Dexcool and yellow bottle Prestone are ethylene glycol. Propylene glycol is less toxic, and potentally less deadly, than ethylene glycol, but it also is a bit less efficient at cooling your engine. Also, most propylene glycol antifreeze products are good for only 2 years. Dexcool and yellow bottle Prestone are good for 5 years. It's up to you what you choose to do. I'm just giving you some of the pros and cons.

[Motorhead62]

The new Prestone is formulated to mix with, or to replace the old, Dexcool.

I use Prestone coolant in the engines I build.

Good Luck

[Motorhead62]

Originally Posted by Norm_N_Tam

Yes, you can replace Dexcool with Prestone in the yellow bottle. There is very little difference between the two, besides the color (Prestone is greenish yellow). Prestone 'Low-Tox' is another story (green color). Low-Tox contains propylene glycol rather than ethylene glycol. Both Dexcool and yellow bottle Prestone are ethylene glycol. Propylene glycol is less toxic, and potentally less deadly, than ethylene glycol, but it also is a bit less efficient at cooling your engine. Also, most propylene glycol antifreeze products are good for only 2 years. Dexcool and yellow bottle Prestone are good for 5 years. It's up to you what you choose to do. I'm just giving you some of the pros and cons.

Just for your information!

Dexcool is not like other coolant formulas. It is OAC, which means "Organic Acid Coolant" and that is why it sludges up when exposed to air and causes problems in some vehicles.

[SWHEATON]

DJD,the coolent did not trash your intake gasket,here is what happened.

You coolent low light came on due to collent being low in expansion/overflow tank.

When you had the oil changed they also filled the exp atnk with green into red dexcool which was not good but doenst cause intake gaskets to go bad,just clogs things up some but nobody noticed cooling in oil at that time.

Whats happened is GM has been having problems with the v6 motors intake gaskets going bad and leaking coolent into the motors which was not caught at the oil change place ,then they just refilled it an sent you out the door. The coolent had gone into your crankcase and you never knew it,lucky your bottom end didnt go south.

Then you said the intake gaskets went bad soon after that when it in reality was already leaking when the oil change place had to add coolent to it at the recent oil change,it just got worse after that which was when you picked up on it.

The intake gaskets went bad many yrs back and had to be replaced on the gm v6 motors in my 93 poinitac,my friends 91 chev lumina,my wife's 98 olds cutllass,and my sons 91 pont grand prix,see the trend here,they all leaked coolent into the motors. The GM dealer told me the design was bad on gm v6 intake gaskets for mult yrs and they were FINALY redesigned a 1yr or so ago to fix the problem.

scott