TEXHAWK0

Does anyone know of a solvent that works on the sludge that forms in the overflow reservoir? It needs to be a chemical that will dissolve the sludge in areas that cannot be reached for physical cleaning.

I tried a commercial radiator flush solution, dishwashing soap, acetone, drain cleaner, and even Lysol toilet cleaner, as someone recommended, and nothing really will remove it all.

Even in areas that can be mechanically cleaned, most things I have tried just smear it around and create an oily film.

vettenuts

Try this web site, there is technician information there but you need to look around.

IM Cool

corvettedoug

Oh how I hate that dex cool sludge. Had that problem on a Blazer and had to flush the system and boil out the radiator to fix. I never did get the film out of the reservoir. Good luck.

Ol'55

For all the $ spent on chemicals I wonder what a discounted "new" one costs? Just a thought. I'm sure someone will chime in.

SteveDoten

I don't think I've ever seen the sludge, I have heard of people using 'bottom wash' a boat cleaner to break up the film

another good reason to do a cam swap, free coolant change

TEXHAWK0

On my daughter's Malibu, I gave up and bought a new reservoir for $30. If all the sludge accumulated in the reservoir, that would be the thing to do instead of spending hours trying to clean it.
I was trying to find out if ANYTHING will actually dissolve the sludge once it is in the system.

I cannot figure out why some cars have the problem and others do not. Is it air in the system, bad radiator cap, what??
I never had a sludge problem with DEX-COOL on my Z06, SS Camaro, or Impala, but the system on our 2003 Malibu forms sludge around the top of the reservoir. I have changed the antifreeze, but have not pulled the radiator hose to see what the radiator looks like inside.

1KLRTOY

I think the "sludge " is rubber from the inside of the hoses that is abraded away by the coolant flowing through them, New hoses and a new tank fixes the problem for 4-5 years

TheDVS1

My experience is that the sludge forms when you mix Dexcool with the old green antifreeze. When I installed a Be-Cool radiator in my old Firebird, I switched to Dexcool as recommended, but I didn't get all the old green stuff out of the system. The incompatible fluids formed a nice filmy sludge that covered everything!

I ended up flushing the heck out of the system about three or four times after running new Dexcool for several hundred miles each time, and now everything is nice n'clear and seems to be staying that way. If you're worried about the sludged reservoir, I'd just replace it.

CMYC4GO

I'd like to get rid of the Dexcool, and switch to the green stuff, but I'm not sure how compatible it is with a LS1. I did it w/my Chevy pickup, and have had no problems.

feeder82

It might be in some cases but my 96 Impala SS had so much sludge after a year, 10k miles that i had to flush the heater core, heat control valve.

nuke61

The sludge forms when DexCool mixes with air in the system. This may be from a bad pressure cap, or incomplete filling of the system, but in any case, is caused by air, per GM and Texaco.

http://www.noln.net/features/feature3.html

As for your question, the only thing that I've found that works *reasonably* for the sludge well is a pressure flush, but it will still have that oily film.

Switching to the green stuff is perfectly O.K. as long as you completely flush out all of the Dex-Cool. Ford, Honda, Porsche, etc. all have aluminum motors too, and none of them use Dex-Cool. Some use the old green stuff, and some use other OAT coolants with formulations that are different from Dex-Cool.

TYSON1997

Give Nitric acid a try. I clean all my motor parts in a .2N-1N mix of Nitric acid. Nitric acid is pretty weak at this low of concentration, no gloves or anything, but it will do amazing stuff. Just make sure you flush it really good. Then add a basic compund to your cooling system such as morpholine, (c4h9no), to make sure your cooling system is slightly basic vice acidic.

TEXHAWK0

Any idea what the long term effect is of nitric acid on the plastics in the coolant system? I think the tank may be polypropylene. Can it cause it to crack if not completely removed or exposed for too long?

nuke61

That would work great if that's the only place the sludge was located. I think the point is that if he can find something that dissolves this sludge without harming the motor, he can be somewhat assured that the sludge isn't hiding out somewhere in the water passages.

DRR

Fitchners = $40 - why bother trying to clean it?

TYSON1997

we use nitric acid on a daily basis and alot of our analysis equipment is plastic so I would say theres not much of a chance of hurting anything. many of our sample bottles are years old. Any leftover acid you have will clean aluminum very well also. Beside nitric acid is a "strong acid" so basically once its used up it will not keep making hydronium ions and creating an acidic solution. You can use regular water and it will counteract the acid and dilute it completely. especially if you use a low normality like .2-1N. Ill bring some from work tomorrow and try it out and let ya know how it goes. Ill try a couple of acids.

chuckster

Not a Chemist... but I did stay at a Hoiday Inn Express...

I have found that "Purple Degreaser" removes just about anything.. Including the skin off your fingertips

Take some sludge and put it in a bowl.. than pour straight Purple on it.. see it it works..

you can get it at Home Depot in a Gallon jug... It's a water based solvent so it leads me to believe it would attack a water based sludge product..

The_Donz

Q: What will disolve Dex sludge?
A: Oxalic acid (wood bleach) does disolve Dex sludge

Yes, it really truly does!

I just did the GM process - it DOES work!

If anyone has questions, just ask

leadfoot4

My C-5's coolant tank has a "ribbed" bottom, that collects some sort of crud, but I wouldn't call it sludge. It looks like hardened, flaky, white "stull" that's pretty much impossible to flush from the tank, as the ribs don't allow you get any sort of tool in there, to stir it up.

tebo1940

What strength and is it safe in engine and radiator?