Brown Sludge

[fatmobile]

Sometimes 2 different kinds/colors of antifreeze mixed in the system, can cause brown sludge.

[One_punchmachinegun]

Could older coolant do this, im really at a loss of what is going on. I drove home after work and temp did not spike up at all, got home and my radiator threw up again. I do have a picture
Under all the stuff there is water/coolant.

[wolf_walker]

Wow, that's scary.

Regardless of the cause, you need the rad out and cleaned/pressure tested, and a lot of really nasty, messy, annoying flushing of the entire cooling system.
Then good water and good coolant.

Prior to that you need to be sure the HG isn't leaking.  I'm not sure where I'd start on that score with that mess already made.

[nathantheengineer]

If you are sure you didnt have any problems when it was just water, (unless you didnt notice when the rad threw up as it all evaporates)? Then i would do the following as a test.

You say you are only 14 miles from home to work so should be ok.

1. back flush the rad and coolant system to remove as much ( preferably all) of the brown sludge as possible. I personally take the thermostat out too to allow full cleaning, remember to turn the heater to hot too.

2. fill with clean water to the correct mark.

3. drive to work and open bonnet to see if anything has let go.

4. before driving home that evening check if you have lost any water.


I am going to guess that the new cap went on the car when you added the antifreeze and that it you had the old one on with plain water?

[ORCoaster]

Start Packing a couple of gallons of water with you.  I suspect that once you back flush this baby you might find a leak in the radiator or the heater core.  Going to have to add extra time to and from work to allow for floor and engine checks and possibly topping off the system. 

I wonder if when on water the old cap just let air come and go and never allowed the system to get under pressure.  Now that it is something is a miss.

[theman53]

Or when he put coolant in it the block ran that little bit hotter and cooked off the rust/contaminants into that mess he has. I have seen mixing coolants and that Radiator stop leak look about identical to what he has going on there. That stop leak looks like that if you run about 5 bottles of the stuff...friend of mine just keeps adding it until the leak goes away, which I don't think it ever does. It just gets to where that is about all that is in the rad at that point.

[R.O.R-2.0]

holy crap, after using a dirty mud puddle for coolant, the crap i saw wasnt that nasty even..

i believe lucas has used beer, mud puddle, bodily fluids, and a few other things as well..

gotta love wheelers!

[One_punchmachinegun]

Update, made it home and flushed it this morning, A lot of crud came out, got it clear, but in the hoses and flanges the stuff is coating the walls. So i got as clean as i could, then filled it up with just water to run it and see what happens. I did some spirited driving trying to make sure it got to temp then came home and checked the fluid. It did take a very little bit but nothing concerning. But the sludge seems like it wants to come back, Little biuld up. So i took a spoon full of it and started trying to figure out what it is... Now it does seem like some type of minerals that have rusted, once you get all the little tiny bubbles to pop, it is this fine mineral texture. I would say that there is some rust and some type of fine black metal or possible rock. But what makes me confused is why does it turn into this foamy stuff? could it be heat and some type of chemical reaction?
Thanks all for your comments and concerns

[R.O.R-2.0]

dump some simple green, dawn, or powdered dish soap into your cooling system.. you need to try and break down that crap and get it out of there..

[JessaBug]

We had some nasty stuff in our coolant lines when we got our car. No clue what it was. Didn't get foamy, but it was thicker and pretty nasty. Replaced all coolant hoses and coolant bottle. Even had the car on a coolant exchanger to get everything cleared out. Still got brown. Not sure the culprit in the end as we did a full rebuild and no issues then. But there was a lot of crud in the coolant passages in the engine. Even after hot tanking, we still had to clean them out with compressed air. Clogged up our head gasket a bit too. I'd be really careful running the car with that stuff in there. Clean it out as good as you can.

[745 turbogreasel]

holy crap, after using a dirty mud puddle for coolant, the crap i saw wasnt that nasty even..

Reminds me of the night I got caught trying to refill, and the cops accused me of dumping. They made me sit on the curb in the dark for 40 minutes while they figured out my car really was dry of coolant, and I was filtering  muck water though a dirty sock.  Took 5 of the suckers to figure it out too.  They advised me not to put that in  my engine...like what, sit around waiting  for it to rain???

[R.O.R-2.0]

We had some nasty stuff in our coolant lines when we got our car. No clue what it was. Didn't get foamy, but it was thicker and pretty nasty. Replaced all coolant hoses and coolant bottle. Even had the car on a coolant exchanger to get everything cleared out. Still got brown. Not sure the culprit in the end as we did a full rebuild and no issues then. But there was a lot of crud in the coolant passages in the engine. Even after hot tanking, we still had to clean them out with compressed air. Clogged up our head gasket a bit too. I'd be really careful running the car with that stuff in there. Clean it out as good as you can.

around the cylinders (in the engine block) is where the water moves slowest, so thats where most of the sediment ends up.

it doesnt take much at all to turn a VW cooling system brown.. using straight water is the best way to make it brown.

as for cleaning everything out, i would take the thermostat out, and back flush the hell out of the block..

i imagine your radiator may be clogged after running that brown goop thru it..

[theman53]

holy crap, after using a dirty mud puddle for coolant, the crap i saw wasnt that nasty even..

i believe lucas has used beer, mud puddle, bodily fluids, and a few other things as well..

gotta love wheelers!

Yep, more than one in there.

Good luck guy. I suggest using the .99 cents per gallon distilled water at the grocery store when you get it sorted. I was amazed at how well bodily fluids and beer make for a coolant. But even more amazed at the clean coolant after my last build when I used the distilled water. Crystal.

[ORCoaster]

Ok Class how about we do a chemistry project here to clean that sucker out? 

Oh geez now what is he going to come up with?

I am leaning towards the rust from the block while using water and some sort of radiator stop leak, lots of it to solve a gasket problem.  Being that the block is metal and this junk is settled on it we might have success with the same sort of fluid we clean our coffee maker with. 

Yepper, simple vinegar.  Mix up a quart of that in a gallon of water and see what you get after running on it for a warm up.  I liked the Dawn Idea too but I would go that carefully after the acid wash.  You could even throw in some baking soda in that mix (a couple ounces) to neutralize the prior acid wash if you wanted. 

I think that is what that high priced radiator flush is, so why not just do it on the cheap. 

[ToddA1]

Radiator flush is vinegar or baking soda?

Maybe make a solution of distiller water and CLR.  Let the engine come up to temperature for a bit and shut it down.  I'm not sure I'd want to leave it in there that long, but it should be able to descale everything.  Of course you'd need to be forward and back flushing everything.

-Todd