Dark Coolant

[dagnabit9]

Took the truck to the dealership toady for an oil/fuel filter change and the service guy saw that the coolant was dark and seemed concerned. Truck has 96,000 miles on it now and has been a strong runner. I tow a fifth wheel with it - in fact I just got back from Albuquerque with it. Does the coolant get dark when it gets old? Could it be an inter-mix of oil and coolant (head gasket problems) or maybe the cooling system needs to be flushed and refilled? Your thoughts and comments please, gentlemen (and ladies too)...

[forddieseldoctor]

Yes the coolant does get dark with age but mostly it gets dark with combustion gasses in it, if there was oil in it there would be a thick slime on the top of it. Have you had to add any coolant, or had any problems with venting or overheating?

[dagnabit9]

Nope, never had to add coolant and there is no puking or overflow noted on the filler. And, for as long as I have owned it, it's never overheated - even when pulling my fifth wheel through the desert southwest.

[forddieseldoctor]

Then I would recommend flushing it out with 2 quarts motorcraft vc-9 cleaner and refill with new coolant. If you want the flushing directions pm me with your email and I'll pass them on.

[Goose350]

Originally Posted by forddieseldoctor

Then I would recommend flushing it out with 2 quarts motorcraft vc-9 cleaner and refill with new coolant. If you want the flushing directions pm me with your email and I'll pass them on.

Ill be sending you a pm

[Big Mule]

I just got back from a 2k mile trip through Az, Ut, and Nevada, when I got home the first thing I checked was my coolant, It was dark as well but did not look like I blew the head gaskets. I do have studs EGR delete and a new oil cooler. I took it to the dealer and had it checked out. They said they pressure tested everything and everything held. They did not now why my coolant was dark but advised me to flush my coolant. So I flushed it and now It sounds like a tea kettle. This is where it gets wierd, It only does this when my coolant bypass is left open, but when I close the valves no more tea kettle noise. So I put my headgaskets to the test and went and picked up 30 12' RXR ties on a trailer. I loaded up my stree tune and pushed it coming up some of the Mt grades when I got home not a drop of coolant. So I opened up the valves on the cooant filter and drove to my mother in laws house empty and sure as sh1t it dribbled some coolant. I am now officially stumped. The trucks temp rides no higher than 195*, so It comes no where near over heating.

[dagnabit9]

Update: Took it back to the dealership last week and had it looked over. The diesel tech there said he couldn't find anything wrong with it and just did a flush and refill. Still runs like it always has (it DOES seem to run better though) and still no problems. Getting high 16s low 17s for MPGs going to/from work. Thanks for all the help!