Coolant is slightly reddish and grainy - PeachParts Mercedes-Benz Forum

benhogan · #1 12-06-2010, 08:36 AM

This is for the new-to-me 190d. I noticed the coolant in the reservoir is slightly oily (slimy), is rust colored and has a grainy (almost sandlike) stuff in it.

I can only guess that this is rust but from where? Isn't the block and head aluminum on these motors? Perhaps the radiator is rusted inside?

The car came with no maintenance records so I have no idea how old the coolant is.

What do you gurus suggest on how to fix this?

vstech · #2 12-06-2010, 08:58 AM

head is aluminum. the water pump, and block are iron.
rust could also come from the water pipes that were used to fill the car.
time for a good read on citric acid flush. have fun!

LUVMBDiesels · #3 12-06-2010, 09:12 AM

it is NOT Dexcool orange, is it?

!!

benhogan · #4 12-06-2010, 09:18 AM

Quote:

Originally Posted by LUVMBDiesels

it is NOT Dexcool orange, is it?

!!

am I SOL if that is the case? would the citric flush fix it.

okyoureabeast · #5 12-06-2010, 09:22 AM

Quote:

Originally Posted by benhogan

am I SOL if that is the case? would the citric flush fix it.

No, but I'd do a complete overhaul of the cooling system starting with a flush and new thermostat.

Neighbor lost a Jimmy to Deathcool

C Sean Watts · #6 12-06-2010, 02:50 PM

Quote:

Originally Posted by okyoureabeast

No, but I'd do a complete overhaul of the cooling system starting with a flush and new thermostat.

X3 - and by that I don't just mean agreed, flush it more than once and use a couple gallons of steam distilled water to do the final rinse and drain. Then, use distilled water to mix the new correct anti freeze.

Get the death-cool out ASAP.

tankowner · #7 12-06-2010, 09:24 AM

Quote:

Originally Posted by LUVMBDiesels

it is NOT Dexcool orange, is it?

!!

Ha! That was my initial reaction too.

Here's another option, it's possible that someone dumped a bottle stop-leak in there. Sometimes that accounts for odd colors and strange things in the coolant.

LUVMBDiesels · #8 12-06-2010, 09:34 AM

I had to replace the radiator on the Suburban last summer. After running DEATHCOOL since 1999 the radiator tanks were 1/3 full of orange greasy crap! I was seriously thinking of putting G-05 in the truck, but I did not want to have issues with mixing it with the remains of the Dex...
FWIW, I did a citric acid flush on the truck a couple years ago and it still was full of gunk!

nelbur · #9 12-06-2010, 11:33 AM

I agree with the stop leak theory. There is one brand that has pellets in an oil base. When the pellets break up they are small fibrous lumps that are supposed to jam up in a leak and plug it. I would just drain and refill the coolant. The more vigorous treatments could open up the sealed leak.

barry123400 · #10 12-06-2010, 11:39 AM

I have a 3.1 buick century waiting for treatment of a simular sort. I imagine either the head gasket was changed out or it was not. Someone may have sometime without cleaning the coolant system out as well. The car runs very well with no indications otherwise of a current possible head gasket problem.

Citric flushes might be too agressive. First I want to find out if it is a head gasket or not anyways. So I will drain the current junk out and put water and liquid detergent soap in. Run for awhile and flush and repeat until it is nice and clean.

Perhaps then run a low percentage of water and anti freeze mix and keep an eye on it for a week or two. If it stays clean then put a normal mix of coolant in.

If not try to find out the head gasket that may have failed and change it out. At least on the 190 you only have one head. On the 301 it might be better for me to change the two out as preventative maintenance rather than just one anyways if it comes to it.

I do not unfortunatly know the past owner or have anyway of contacting him.

benhogan · #11 12-06-2010, 11:55 AM

I thought it might be the head gasket but wouldn't the coolant be black as opposed to reddish though?

It might very well be the Bar's Stop Leak gunk. I think the idea is, as the gritty particles get exposed to air via the leak, they solidify and stop the leak.

I am gonna drain the coolant a few times and see what happens.

I'm waiting for a warm day!

ConnClark · #12 12-06-2010, 11:53 AM

I would replace the radiator cap as a precaution. It may be leaking air and allowing O2 into the coolant contributing to rust

tankowner · #13 12-06-2010, 12:29 PM

Quote:

Originally Posted by LUVMBDiesels

I had to replace the radiator on the Suburban last summer. After running DEATHCOOL since 1999 the radiator tanks were 1/3 full of orange greasy crap! I was seriously thinking of putting G-05 in the truck, but I did not want to have issues with mixing it with the remains of the Dex...
FWIW, I did a citric acid flush on the truck a couple years ago and it still was full of gunk!

I bought a 2001 Chevy venture a couple months ago - read a lot about the Dex-Crap and the known problem with failing IM failing and leak collant into the engine - GM knew about, but refused to fix the problem.

Anyway, the POs reported no problem with coolant loss or overheating - and I haven't noticed any problem after these first few months. I did drain the coolant to attempt to get rid of the Dex-Crap. The resevoir did have some of the greasy gunk and there was some on the interior of the radiator cap as well. I cleaned up as best as I could - flushed, and refilled with G-05. Even after a flush, the G-05 is tinged the dreaded orange again, so I will hit it again next year to try and get as much of that stuff out as possible. It is also advised, although I still need to do it - to replace the radiator caps, in some models they were updated.

Is there some known issue with mixing G-05 with Dex, I assumed anything was better than Dex and the G-05 would offer the same protection. Actually, some attribute the failed IM gaskets to the Dex and suggest that G-05 is better in that respect.

Oh, and regarding the Stop-leak theory. recently my father-in-law and I did some work on his van - it had a corroded coolant pipe that needed replaced. He realized it on a long trip and so added a bottle of the stop-leak. After purchasing a new pipe, we drained the old coolant which was dark in color and had little bits of junk from the stop-leak. So, it's possible that this is your issue, but I would also check out the other ideas here too.

TylerH860 · #14 12-06-2010, 02:24 PM

That Dex-cool is some nasty stuff. It pretty much writes off any GM product for me at a dealer auction over 15 years old. All I look for is the 3.8, 4.3, and 5.7s out there.

The coolant is not pressurized in the expansion tank reservoir, as the cap can make it easily confused with windshield washer fluid. The ones with old Dex cool in there build up a really nasty gooey coating on all the surfaces. It really is a shame.

My '94 Buick had a nasty looking heater core because of it. I made specific instructions NOT to refill the system with dexcool.

tbomachines · #15 12-06-2010, 11:51 AM

If it is reddish/pink there is a chance that ATF got into the coolant as well, but the oil will separate. If there was a leaky radiator and stop leak was used, there is a chance ATF got in there as well since (at least on the w126? correct me if wrong please) the radiator doubles as teh trans cooler.