: Coolant... why stick with green?

05-29-09, 01:52 PM
So I was bored at work and going some random google caddy searching....

I found this article on caddyinfo.com.


Cliff Notes ( so ignore the stop leak, but the article had a couple guys state that once your car had green coolant, there was no advantage to flushing it and going back to dexcool )

That implies ( obviously ) that Dexcool has an advantage and works better in our cars. Now we all know Dexcool can get gummy over time... but no where did it mention why the dexcool advantage was lost once you had the green stuff in..... I heard mixing the two can clog the heater core... but that's not why these guys were talking like this...

Anyone know why once your GM Dexcool car has regular green antifreeze in it... you wouldn't want to go back to what GM calls for in the 1st place?

05-29-09, 02:01 PM
here is something I found:

Converting to a different coolant formula always requires a system flush. Converting to from green to DexCool is no different. However, because of the coating properties of the silicate-based green coolant, it is impossible to know for sure if all of the green coolant has been flushed out. In fact, it's likely that it hasn't been completely removed without a trace left behind. Any trace of green coolant present in a DexCool system will degrade the life of the corrosion inhibitors in the coolant, drastically reducing the time between service intervals. So if you have a car that came with green coolant from the factory and want to switch to DexCool for the long service intervals, then be aware that traces of silicate coating will remain on engine components, even after a flush. It will take another 30k mile flush at the very least to rid the system of silicates. That said, DexCool shouldn't harm your engine, but it is impossible to predict how the various accessories, gaskets, etc. in your particular car will react to DexCool.

Switching from DexCool to green coolant seems to be less of an ordeal, since GM and Texaco claim that mixing green coolant with DexCool causes no damage to the engine as long as 30k mile service intervals are observed. However, there are the same uncertainties regarding accessory and gasket longevity when switching from DexCool to green coolant as vice-versa.

I guess basically if you switch colors, you are supposed to flush the system completely, but the green stuff is harder to flush because it coats the metal more.

05-29-09, 06:54 PM
wow... thanks 510... that's EXACTLY what I was looking for....

05-29-09, 08:33 PM
damn tom... do you have like a whole other computer that taps into caddy headquarters? u come up with all of the sht and with it very quickly!

05-29-09, 08:54 PM

I do a lot of reading and end up with a lot of my own questions, so I have gotten pretty good at searching and finding answers. :highfive:

05-29-09, 09:48 PM
no biggie... just curious lol

05-29-09, 10:13 PM
I have gone to Evans coolant in all my vehicles. Been very happy with it. Suggest you research Evans as an alternative.

05-29-09, 10:50 PM
Why does it matter? The radiators leak and need to be replaced before you even have a chance to flush the damn coolant in these cars :histeric:

05-29-09, 11:15 PM

05-30-09, 06:00 PM

Thank you ladies and gentlemen...I'm here all weekend :getaway:

05-30-09, 07:18 PM
Dex cool allows longer time or mileage between changes. Run what ever you want, just change it every couple of years as it becomes acidic over time and can eat away at aluminumo. If your wanted I sure you could test it yearly.

Dex cool is just like 100,000 mile changes.


10-08-09, 10:38 AM
Just as a follow-up on this thread, I checked my coolant before a road-trip last weekend and the bottom of the reservoir cap is getting the Dexcool sludge and there is a coolant smell around that area under the hood...I'm on radiator #2 and it's not leaking...at 45k miles, you guys think it's time for a flush (5 yrs)? Can you flush these radiators yourself or are they a reverse-flow dealer only kind of thing?

10-08-09, 12:10 PM
You can drain and flush it yourself. It's simple. Drain from the lower radiator hose, fill in resevoir until it stop going down, run car while filling the resevoir until it stops going down again. You can flush with water the same way before you refill with coolant if you want.

Also, mixing the green and red creates sludge and messes with heater core and water pump.

10-08-09, 01:09 PM
I understand you aren't supposed to mix, to my knowledge mine is not mixed (coolant is the correct dex-cool color) and the sludge is pinkish-red under the cap, just figured I have hit the 5 yrs since my production date is actually in '04.

Good to hear I can flush it myself.

06-08-10, 10:15 AM
Has anyone experienced any troubles what so ever with Evans NPG+ in their Northstar? I have been researching this for my Honda Goldwing motorcycle and have read many positives and am thinking of using it on my SLS. It has 130,000 miles with a water pump replacement at 90,000 miles.

Have to say this site keeps me up late at night with all the info here, thanks everyone for all their info!:hmm:

06-08-10, 10:28 AM
Aside from mixing, the other problem I've heard about Dexcool is it doesn't like to be exposed to the air for a long period of time. I don't know if there is any truth to that. But I will say Dexcool's anti-corrosion properties DO work much longer than conventional ethylene glycol.

The radiator thing bugs me though. Are they inadequately isolated? Has anyone tried a regular aftermarket replacement, like, say, a Napa unit?

06-08-10, 10:30 AM
Most of us don't have Northstars in this sub-forum.

06-08-10, 01:19 PM
just for the record I drained mine, flushed it a couple of times with water by filling, running the car till warm, letting it cool, and draining it... when I was sure it was only water coming out I filled it back up with a dex-cool compliant anti-freeze and called it a day.

06-01-12, 04:13 PM
Anyone know of a good coolant system cleaner to use after this whole debacle? I got my eye on the BG products. I think we used BG's fuel system cleaner at Mercedes if memory serves me well. I just bought an '03 CTS that had previously gotten a blown head gasket replaced and now I see someone filled er up with green. After reading this thread I'm betting that Dexcool mixing with others was the culprit.


06-04-12, 12:00 PM
...side note...I see that SoJersey05V was banned.....what did he do to get banned?

06-04-12, 01:08 PM
...side note...I see that SoJersey05V was banned.....what did he do to get banned?

I forget...he was relatively local to me and not a bad guy at all, I think there was just a disagreement and some name calling a while back and it resulted in his banning.


...side note...I see that SoJersey05V was banned.....what did he do to get banned?

I forget...he was relatively local to me and not a bad guy at all, I think there was just a disagreement and some name calling a while back and it resulted in his banning.


Wow cadillacforums website FAIL once again. Error Error Error....seems like everyday now. :nono: