"Mud" in cooling system

[jason07-1zzfe]

What would cause a mud-like substance to form in the cooling system?

I found it in a small 5/16" hose that is I think just a bypass for a thermostatic valve that is just before the heater-core. The valve prevents an overheated engine from passing over-temped coolant into the core, which may cause it to blow, spraying boiling water on your legs

Anyway, this bypass hose had at least 3" in length completely filled with this gunk that has the color and consisitency of mud. Nearer to the valve it became harder. I had to clean the port on the valve out too. But most of it was like mud.

Never noticed anything anywhere else in the cooling system.

Secondly, why there? Just collects in the most restrictive area?

[ June 24, 2003, 03:55 PM: Message edited by: Jason Troxell ]

 

[MolaKule]

Seriously, collect it and put it in toluene and we'll have it analyzed.

Were there any fish bones in there?

[ June 24, 2003, 04:03 PM: Message edited by: MolaKule ]

 

[jason07-1zzfe]

What kind of analysis were you thinking of? Just elemental spectrograph? Or something to determine chemical composition? That can't be cheap.

I think I still have some. I cut about 2in of the hose off. I could get some out of that section.

Actually it had a pinkish hue to it, hmm kind of like salmon, but no fish bones

 

[davidc]

I found the same in a recent used car purchase that I made.
Low miles (
I used a two part Prestone dry acid flush / neutralizer to flush the system.

Molekule - you're the chemist - what do you think it is?

 

[UncleS2]

Me too. After running RMI-25 in my cooling system for ~9 months now, there's a light brown sediment in the bottom of my overflow tank. I first spotted it months ago, looks a bit deeper now than then. Car has cast iron block, aluminum head & intake. I keep meaning to remove the tank(looks like no easy job, though

), then shake it up good & pour it through a coffee filter.

 

[VaderSS]

The sediment caused by RMI-25 is normal. That is the way it flushes the system. I just siphon the tank out, then spray the snot out of it with a water hose, then siphon it out again. That usually cleans it out great.

 

[ssjones]

You don't mention the brand of vehicle. If you have a GM, they typically add "clay pellets" with the Dexcool. This will definitely turn to mud and needs to be flushed before problems develop. Most folks with GM Dexcool equipped vehicles that don't flush or change the coolant frequently almost always have heater problems. I flush both of my Dexcool-filled LT1's every two years and haven't had a problem.

 

[Spector]

Sounds very much like some sealers used to stop leaks. In fact, Barrs Stop Leak has that brown mud like color and consistency.

 

[jason07-1zzfe]

The vehicle is an '89 BMW 325is. But I was running Havoline Dexcool.
I have since flushed it and refilled with distilled water and Zerex G05 coolant.
I don't have any leaks and I have never added any kind of stop leak product. But I have only had the car for the past ~60k.

 

[Jim Spahr]

Please always list your car and some details like miles and mtce history. If your car is a GM and/or you have used the Havoline, there's your problem. The 'long life' coolant is sludging up. Some say it is because the GM manuf. plants put in a 'Stop Leak' pellet at the factory. Others say you just need to change the coolant every year and there will be no problem with the long life coolant.- he wrote, dripping with irony. I have a 94 Impala SS which originally came with the green coolant. I upgraded to the new improved long life DexCool and it immediately sludged up. I really had a diificult time getting all that mud out of my cooling system. I used clear water flushes, Prestone radiator flush, block flush, and so on. The reservoir with the many compartments was the hardest part to clean completely.

 

[Drew99GT]

My Dad's blazer had to get a new radiator because it was plugged with crud. However, my Moms Olds 88 doesn't seem to have any dexcool problems. I recently put a new thermostat in and flushed the system, and was amazed to see it was spotless inside with 80K on factory installed dexcool. There was some light crud in the overflow however.