What happened to my coolant?

Dave Kay

Adventurer
Can anyone explain this; Installed a bigger, re-cored radiator in Jan '09, all new hoses, flushed the system, filled w/50-50 Dexcool and distilled water. First time using this stuff but for some reason I was told it's better than the green stuff even for older rigs. (GMC 1986) The truck hasn't been driven more than 10k miles since that work was done and the cooling system was full whenever I popped the cap...

Fast-forward to today----- I'm changing out the thermostat and to my utter shock and amazment I discover that my entire cooling sytem is FULL of some kind of rusty residue--- clinging to everything--- I mean the stuff is thick! What the???? Inside the radiator walls it's coated with this stuff and YET, the coolant that I drained into a bucket looks clean and new.

What have I got here and how do I get rid of it? Help, anybody?
 

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DT75FLH

Adventurer
when you switch to dex cool you usually have to flush the system WELL..as in fil with water....run to operating temp....drain and repeat at least once more (this is to flush the heater core also).

if you just drain and fill there was enough green coolant left to GEL with the dex cool.

its usually not a good idea to change coolant with a veh that was run with green coolant. the dexcool has some issues also.

your better off flushing system with the directions above 2x...then refill with green coolant and hope you get everything out. .
 

dwh

Tail-End Charlie
According to this page:

http://www.sancarlosradiator.com/dex-cool.htm

"The "recommended" service intervals of Dex-cool coolant is 5 years 100K miles and in some cases 150K miles. These extended service intervals have not proven to be any thing but trouble for the consumer. In some cars, the coolant tends to turn to a thick, gooey, sticky, muddy, gritty, orange corrosive gel that fouls the radiator, heater, plugs coolant passages in the intake manifold and heads, and many times starves the water pump, resulting in overheating, and leaking. Mounting evidence suggests that Dex-cool reacts with plastic sealing surfaces, allowing leakage at the intake manifold gaskets. The best thing to do without voiding any warranty, is to change your coolant every two years with the recommended coolant. CHANGE THE COOLANT EVERY TWO YEARS!! ESPECIALLY IF IT DEX-COOL!! DEX-COOL IS THE WORST OFFENDER. DEX-COOL DOES NOT LAST 5 YEARS OR 1000,000 MILES"
 

Dave Kay

Adventurer
when you switch to dex cool you usually have to flush the system WELL..as in fil with water....run to operating temp....drain and repeat at least once more (this is to flush the heater core also).

if you just drain and fill there was enough green coolant left to GEL with the dex cool.

its usually not a good idea to change coolant with a veh that was run with green coolant. the dexcool has some issues also.

your better off flushing system with the directions above 2x...then refill with green coolant and hope you get everything out. .
Thanks, I've never seen coolant do this and I see now why some don't like the Dexcool. Actually, I thought I did a pretty thourough flush originally but wasn't aware of the green/orange mix issue. In fact, the coolant looked fine before I last parked the truck in July 2010 and haven't put hardly any miles on it since.

So now I wonder what can be used to really clean this stuff out? The article mentions 'chemical flush,' but exactly what kind? Who makes it? Some places I see people talking about powdered automatic dish washing soap. Some guys swear by this method but before I make more probs for myself can anyone weigh-in: Is the dishwashing soap method effective and/or safe? How much? How many flushes? Whatever?
 
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dwh

Tail-End Charlie
According to that page I linked above:

"The residue it leaves behind is very sticky, and likes to find areas in the engine and other areas to "drop out" or "fall out " of solution and stick to the wall surface of engine and radiator. If the residue is in the radiator, hoses, or recovery bottle, it's relatively easy to clean and remove the debris. When the residue is in the heads and block, only a chemical flush will remove this orange mud."


EDIT: Personally, I'd take it to a radiator shop for a good pro power flush.
 

matt s

Explorer
It happened in my F150. Chunky sludge nasty. I found a shop that had an older style flush kit that according to the owner might just have the ability to flush it out of my system. Remind you mine was BAD. Like goo.

Long story short they had me run some radiator cleanout stuff for about 30 minutes in the engine then bring it in. We got it out, it took a couple hours and several flushings. Went with the traditional green after that.
 

Dave Kay

Adventurer
Thanks guys, at least there's some semblence of hope here and THANK YOU GM for tricking me into buying this junkie-product.

A trip to the radiator shop is not an option for me at thi$ particular time. So this has to be a DIY project with method(s) that will not fail to get the job done.

Ok, I'm seeing Prestone stuff that's 10 min flush, then there's 3-6 hour flush, then there's the mysterious "chemical flush," (of which I haven't seen on the shelf for over a decade) then I see some kind of GM Heavy Duty flush and a few other 'oxy-clean' kind of things that look like probable hoaxes. What I'm hoping to get is something to really clear this mud out good. Keep in mind, this cooling sys has maybe 10k miles and everything is practically brand new. This dex-crap has coated the inside of NEW hoses, NEW radiator insides, and I have no doubt that the block and entire system are full of it. Luckily, it seems fairly light. But exactly what/which product works to neutralize this stuff and clean the coolant passsages in the block too?
 

bob91yj

Resident **************
Dishwashing machine soap is a great flushing agent in my experience. I've used it to clean transmission fluid out of engines/radiators when I worked for Allison Transmission. Not sure that brand really matters, but I always used Cascade powder. It may take a flush or two, but it should get it clean.
 

dwh

Tail-End Charlie
And from a different place:

http://forums.corvetteforum.com/c3-tech-performance/2395596-radiator-cleaner-flush.html


"Prestone used to make a cleaner for GM P/N 12346500.

It was also sold under Prestone P/N AS100 Heavy Duty Cooling System Cleaner

Here is the GM TSB and Instructions #99-06-02-012D (Online or at a GM dealer)

It is not made anymore but these are the components.

9 dry oz of Oxalic Acid (DAP Wood Bleach)
2 dry oz of Sodium Carbonate (Arm & Hammer Super Washing Soda)"



EDIT: And apparently you need to something else to neutralize the acid after the cleaning.
 

Dave Kay

Adventurer
Thanks Mr. DWH and thanks to all for the tech-help. Guess I'll be making a major shopping trip tomorrow to collect-up all the necessary chemical products and hazmat suit, losing yet another day in prepping for our weekend trek I'll prolly have to reschedule... (wah, wah, wah, wah wah.... :()

Meanwhile--- CHEERS!

P.S. hey--- how 'bout a sixty one page DIY cooling sys flush posting w/pics....... NOT!
 

matt s

Explorer
FWIW thinking back it was the prestone 10 minute stuff they had me use. They just had me do it for 30 minutes to really break it down.

You might call a lube place. It only ran me $100. You could get there just buying all the supplies trying to do it yourself and you have all the crap left over in a bucket or two.
 
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