Dex-cool / Prestone (unknown) left orange stains

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Hi guys,

Several years back i had a thermostat that went bad. I changed out the thermostat and refilled the engine with Prestone dexcool...When i took the thermostat housing off and drained what coolant i could i noticed the system and internal cooling passages were clean...aluminum or metallic looking...nothing remarkable...everything was fine for a week then the water pump failed...

Due to my inexperience i took it to a shop at had them do it...they used an unknown brand of dexcool but i am 99% sure it was prestone...

fast forward 2 years and THAT pump failed...by this time i had gotten fed up with that mechanic and decided to do the water pump job myself...way too easy.

Well, when i got the components off what i noticed this time was that whatever the previous dexcool coolant manufacturer was...left orange stains all over the coolant passages in the system...i could touch it with my finger and it would stain my finger slightly...

was this the prestone [censored]?

when i originally removed the thermostat housing no staining was on the system...around 120k... then at 155k when that pump went bad 2 years later i've got all this staining and dye going on.


Let me explain a little more since dex-cool has all these horror stories associated with it...

i do NOT have gelatin or blob like residue...the passages are not blocked...

it is as though someone took orange food coloring and mixed it in my cooling system and everything has been dyed/stained orange...

Needless to say i was [censored] and i emailed Prestone with pictures of the stained system...they never responded...i said it could only have been their product and the use of inferior or cheap dyes to cause this staining...because im 99% sure that the mechanic used prestone as well...(small time shop mechanic has his products delivered from the autozones and carquests around town)

Has anyone noticed dexcool to stain their cooling system? if so do you have remember if it was GM brand dex-cool or whether it was Prestone or perhaps another brand? (I've never seen any other brands of dexcool besides GM and Prestone's Dex Compatible coolants...which is why im leaning so much towards the prestone having used a cheap inferior dye to cut costs and stain the [censored] out of my cooling system...)
 
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Why are you so worked up about the color of your coolant passages? Does it clash with your paint job? If it is not causing problems with your cooling system (and you said you have no "Deathcool" symptoms), why does it matter? Would you be upset if you used Royal Purple gear oil and it stained the inside of your diff cover purple?
 
Not particularly, im just a little irked because i'd like to actually switch to regular eth gly anti-freeze and now im a little hesitant because i have a orange stain residue that gets very lightly "chalky" when dries...(could just be hard water deposits, nonetheless orange)

And im a little worried that perhaps theirs more in there than just dye... its just a little bothersome for a product you pay top dollar for to cause [censored] like that...

I dont understand how that would NOT concern you, i may ask what if your gas stained your fuel system? or emitted a foul odor? wouldnt you be upset?
 
The only thing on my vehicles that dexcool stained was the plastic overflow tank. You can try and do a distilled water flush but I don't think it will remove the orange staining. I have used OEM, prestone, Havoline, and oreilly dexcool.
 
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Never seen Dex-Cool stain the inside of a cooling system when the system is in good shape. Never seen Dex-Cool stain a cooling system, at least on the two GM products I've owned that have used Dex-Cool.

It's possible the mechanic used regular old tap water instead of distilled to top off your system after replacing the water pump. Those minerals would indeed coat anything in the cooling system, and just might bind some of the dye. It's also possible they used old-formula orange Dex-Cool. The modern stuff is a reddish-orange color.

I don't get the hate towards modern reddish Dex-Cool. The stuff works just fine, and doesn't have the issues with the old orange Dex-Cool.
 
Originally Posted By: sciphi
Never seen Dex-Cool stain the inside of a cooling system when the system is in good shape. Never seen Dex-Cool stain a cooling system, at least on the two GM products I've owned that have used Dex-Cool.

It's possible the mechanic used regular old tap water instead of distilled to top off your system after replacing the water pump. Those minerals would indeed coat anything in the cooling system, and just might bind some of the dye. It's also possible they used old-formula orange Dex-Cool. The modern stuff is a reddish-orange color.

I don't get the hate towards modern reddish Dex-Cool. The stuff works just fine, and doesn't have the issues with the old orange Dex-Cool.


+1 I wonder if they even used dexcool when they topped it off. Prestone all makes is essentially the same as dexcool and is "all makes/all models." I agree that is is probably minerals from tap that could have caused this and modern dexcool is good stuff. The only stuff was fine too, it was gaskets and not the coolant.
 
Originally Posted By: sciphi
I don't get the hate towards modern reddish Dex-Cool. The stuff works just fine, and doesn't have the issues with the old orange Dex-Cool.


You have a source for this? Ive never heard of a formula change for dex cool and a quick 5 minutes of research confirms that there has never been such a change. Only changes is gasket materials used by gm and other manufacturers to be more compatible with 2-eha
 
Originally Posted By: AntsinmyEyes
Originally Posted By: sciphi
I don't get the hate towards modern reddish Dex-Cool. The stuff works just fine, and doesn't have the issues with the old orange Dex-Cool.


You have a source for this? Ive never heard of a formula change for dex cool and a quick 5 minutes of research confirms that there has never been such a change. Only changes is gasket materials used by gm and other manufacturers to be more compatible with 2-eha


You know what they say about "hearsay" and "bias confirmation". I'd heard it from a reputable source, the lack of issues associated with old Dex-Cool seemed to confirm what I'd heard, and so it got repeated.

You're correct, there's no quickly-found evidence to suggest that 2-EHA got dropped from Dex-Cool.
 
Drain as much fluid as possible then fill with distiller and 2x dishwasher tablets. Run til thermostat opens, drain, repeat.
Fill wih 50/50 and sleep easy
smile.gif
 
Originally Posted By: Olas
Drain as much fluid as possible then fill with distiller and 2x dishwasher tablets. Run til thermostat opens, drain, repeat.
Fill wih 50/50 and sleep easy
smile.gif



The only issue is that most dishwasher tabs in the US are lacking phosphorous which was the best cleaners for cooling systems. You are better off finding a citric acid flush as they are easier to find and will offer similar results to the dishwasher tabs of yesterday.
 
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