I need some help with this one. While on vacation and towing our travel trailer, we noticed a strange oder. At first I blamed it on the diesel fuel additive I was using. When we arrived at our destination (aproximately 2K miles form home), I did some more investigating. I discovered that I was low on coolant. I also noticed that when I removed the cap from the degas bottle I found the source of the strange oder. I added about 1 gallon of water to the system. I noticed the degas bottle getting black inside.

I then suspected the EGR cooler, which I replaced in January at 99,988 miles. So, we drove home. When I got home, I added 1 gallon of antifreeze to the system. Contiuned to look for leaks, and couldn't find any.

During my continual investigation, I discoverd the connector hose on the turbo was cracked, so I replaced it ($79.95 at the Ford dealer!). I can tell the truck is stronger now.

I have been driving the truck for about a month since I replaced theconnector hose. I have not added any more antifreeze. The degas bottle is so balck I cannot see into it and my coolant is turning black.

I changed the oil last weekend and drained out the full 15 quarts, so I'm not lossing or gaining oil and the motor has plenty of power at 118K miles.

Any ideas?

 

you may have gotten some oil in the cooling system that stuck to the sides of hoses, radiator, block, etc and it is just washing it all off. or the oil could have gotten in there and needs to be flushed out. i would recommend flushing the coolant system and getting a coolant filter. the filter is more or less just a preventative maintenance add on to save your EGR cooler and your oil cooler. these engines are known to have excess casting sand in the block left over from when they cast the blocks at the manufacturer. if the coolant still turns black after you flush the system then you may have a more serious problem. it probably wouldn't be too bad of an idea to purchase a new degas bottle either.

 

Oil contaminated coolant will turn brown or tan and get thick as it suspends in the water. Is the coolant still a thin consistancy (low viscosity like water)? Black would mean carbon to me.

 

what kind of coolant are you using

 

just out of pure ignorance how does carbon get into the coolant?

 

First of all I have to say I have never heard of black antifreeze, so all this is speculation. That is why I asked about the water consistency. Also, satcom's question is a good one. I would also ask - has the coolant system ever been flushed? I plan on doing this around 100k - probably at 90k.

When you have bad head gaskets, you get combustion gasses into the coolant system. These gasses have some carbon, just usually not much. If there is also a bad combustion problem in a cylinder - maybe these combined could produce soot in the coolant.

Maybe a bad EGR cooler and a simultaneous issue with a poorly performing water pump. Usually coolant enters the exhaust, but w/ low coolant pressure, maybe exhaust gasses would enter the coolant at a dirty EGR cooler? Just seems like a long shot as I would think this would happen only w/ evidence of other problems.

As I said - just speculating.

I have heard of coolant waters turning black in the industrial water treating industry. This is due to bacteria in the coolant and not enough treatment chemicals (in closed loop systems that have been ignored for a long time). A source of organics also has to be present for the bacteria to feed on. I couldn't imagine that this would be the problem.

 

Thanks for the suggestions. To answer your questions, the coolant is still the consistancy of water. It has not gotten thicker. I cannot see an oily film floating on top. The coolant was replaced by the dealer when they replaced the EGR cooler in January. They replaced it with Motorcraft 'gold' coolant. I do not know if they flushed the system.

One other symptom I forgot to include in my original post. When I tow our travel trailer, the fan clutch engages, but the engine temp gauge doesn't increase. The outside temp didn't effect it, even when it was in the 40's while in WY. The only other time it has engaged is once while pulling our trailer up a steep long hill with the outside temperature at about 95. The other time was last fall when pulling the camper on vacation. We kept smelling anifreeze, but no leak or increase in engine temperature. The problem was a leaking EGR cooler.

When I added a gallon of coolant (Motocraft Premium GOld) after our last trip, I smelled the antifreeze to see of they had put a new oder in it. I couldn't smell anything. The oder I smell now is not the typical antifreeze smell. It's hard to describe.

 

Find yourself a good 6.0 diesel tech. Speculating will cause you many sleepless nights and cost you a lot of wasted money. Have someone find out exactly what is wrong and then get it fixed.

Just my opinion.

 

Please keep us posted on this, it is an interesting and apparently unique issue. Hopefully it is nothing major, but taking it in is a very good idea.

Not sure how speculating wastes money. The very reason to use the word speculate is so there is no implication of a "recommendation". Just to make a point - most posts contain speculation since only the OP is there with the vehicle. This is especially true if the OP does not have a way to get the DTC's, if there are any. Way to often we ALL post a solution like it is a "sure thing". Clearly these vehicles are very complicated and there are almost always multiple things that can end up being the cause of an issue. My speculation was in response to a direct question - hopefully you haven't lost sleep over it (I'm betting you haven't).

 

Thanks, guys, for your help. I will keep you posted on what I find out is the problem.

 

I took my truck to City Diesel and the tech said the egr cooler is leaking. I am looking for information about deletling the egr cooler. Any suggestions?

I have read in various forums about head gasket problems with the 6.0. If I'm going to pull off the intake, I may go ahead and replace the head gaskets. Who has had expereince with this? Any suggestions?

 

I was just about to look this post up and see what you had found. Thank you for posting the findings.

Since this is a repeat failure of the EGR cooler (at least that is what I recall reading), you need to understand why it is failing. Most likely you also have a plugged oil cooler (water side). From what I read, this is common. It still does not explain the black (non-oily) coolant. Did the mechanic comment on what turned the antifreeze this color? When an EGR cooler fails, it usually shows itself by water in the exhaust since the coolant pressure is higher than the exhaust at this point.

If you know you have a bad EGR cooler and you have not seen white smoke, I would have someone check your water pump discharge pressure. You should also check the pressure in your degas bottle.

 

The tech said the coolant has soot in it. I asked him about the oil cooler and he said he wouldn't know for sure until he pulls it out and pressure checks it.

Thanks for suggesting the water pump. I'll get it checked.

 

Bismic, I have been thinking about your comments above. BTW, I have not had the water pump discharge nor the pressure in the dagas bottle checked yet. If the oil cooler is plugged, wouldn't that reduce the water pressure in the EGR cooler, thus allowing the exhaust gases & soot to enter the coolant system?

 

What is unusual is that I just have never read any threads where the "plugged oil cooler / leaking EGR cooler" combination showed up as sooty coolant. I do not know the typical coolant pump suction pressures, but it would sure seem that what you are thinking could happen.