I'm about to have an analysis done on my antifreeze, but in the meantime, I thought I would ask for opinions.

Took off the radiator cap and there was tons of black "sludge" (silicon consistency...like rtv gasket, etc) ...Thing is, the "sludge" smells exactly like the hoses. Its definately not oil (not consuming), so my thoughts were on fuel in the coolant. What else would eat away the hoses and produce such a slimy/gooey substance? FUEL? how would fuel get into my coolant? Injection tubes...cracked head...........??????? Any thoughts would be greatly appreciated.

 

Dose it smell like diesel? And what color is your oil? Brown milky or ? would be coolant in the oil. I would pull the top radiator hose off and check inside.

What is "sludge" ?

There are different "types" of sludge, they are of different appearance ranging from light brown to opaque black, they range from semi-liquid to solid, and they can be formed by different chemical reactions.

Since any sludge is formed primarily from the engine oil, the oil itself appears to be at fault. Actually the oil is the victim of mechanical and chemical attack.

The formation of sludge is a very complex interaction of components which include mechanical and thermal stress and multitude of chemical reactions.

Although there are thousands of documented engine failures in the field, not a single research chemist has to date succeeded to create a "synthetic" sludge under controlled laboratory conditions. The real life conditions are therefore so complex as to be virtually impossible to duplicate in laboratory, yet hundreds of engines all over the world fail daily due to sludge formation.

While some engine types are more prone to sludge formation, the fact is that only very small proportion of the "affected" engines actually fail in service.

For example out of the over 3.3 million Toyota engines that are "affected" only about 7,000 of them have had serious failures. That is 0.2% or about two failures in 1,000 engines.

Sludge in gasoline engines is usually black emulsion of water and other combustion by-products, and oil formed primarily during low-temperature engine operation. Sludge is typically soft, but can polymerize to very hard substance. It plugs oil lines and screens, and accelerates wear of engine parts. Sludge deposits can be controlled with a dispersant additive that keeps the sludge constituents finely suspended in the oil.

"Black Sludge" is defined as thick to solid material with low water content, of dark color, light oil insolubles, and typically found in rocker cover, cylinder head, timing chain cover, oil sump, oil pump screen, and oil rings in variable quantities.

Sludge in diesel engines, is soot combined with other combustion by-products which can thicken the oil to gel like sludge. This sludge is typically soft, but can also polymerize to very hard substance. It plugs oil filters, oil lines and screens, and accelerates wear of engine parts.

 

Can anyone just explain how fuel might get into the coolant?

***Thanks in advance for any knowledgeable answers***

 

This is just a suggestion but maybe a cracked head gasket. When the cylinder pressurizes it could be pushing fuel and/or soot into the coolant. Im not saying this is it but its just a suggestion. Other than that im not real sure how fuel could be getting in there. Keep me posted im intreged.

 

The only way coolant can be contaminated with fuel (on our trucks) is if the head cracks around the injector allowing bypass fuel to mix with the coolant in the head. I have never seen it happen on a cummins, but that doesn't say a whole lot.

 

Cracked head or defective head gasket.

 

I was watching a show on TV this week. This is a somewhat common problem on Ford's. The injector seat cracks or wears, and allows the high pressure fuel to escape into the cooling passage.

I think the Cummins has a similar design around the injectors, but I could be wrong.

 

Thanks to everyone for the feedback. Another recommendation was to check the o-ring on the injector. I just had another oil analysis done, nothing wrong, still waiting on results of coolant. With my hoses deteriating, I wonder if I may be a victim of the acidic additive of DexCool. I ran Mopar coolant for 600,000 miles... no problem. Then I change, and all goes to hell. After much research, could possibly be the DexCool. Ever pull out clumps of gooey deteriated hose? Freaked me the F out! Flushing out tomorrow...

 

Now the whole story comes out.

Why would you use Dexcool? Confuse the Rams head with a Bowtie? OAT and HOAT coolants are not compatable.

 

...a recommendation. I could kick that guys a$$! This many miles, I should have stuck with what works. Lesson learned. Hopefully not a costly one. Of course, its pure speculation, but probably obvious! Granted, I didnt mix the coolants, I did a recent flush and changed out my ORIGINAL hoses and then filled up with death. ***Confused with a Bowtie? I wondered why I bought 8 sparkplugs instead of 6