I have a c15 (L4X) in a 740b haul truck. Was down on power and when i drove it when it hit 7th gear would really struggle. Did injector cut out test and it had a hard time maintaining rpm and would kick out test. When i got it to run it said questionable on #1 and 2. Pulled the injectors and found thick pasty oil that is metallic on bottom of number 2 and 5 injectors. Also found a few injectors that had some coolant on them. I get the coolant is the cups(machine originally came in for hydraulic oil in coolant so thinking that's why the seals failed) Have never seen the pasty metallic goop on the bottom of the injectors. I did check return fuel and found no bubbles in it. Thanks for the info
Are you sure it isn’t fuel in the coolant that you’re seeing? I’m not sure about the goo unless it’s a silver anti seize.
I've seen the black thick crud before--contributed it to injector leaking around seating area of injector sleave. Your replacing injectors and resealing sleaves--I wouldn't worry over it.
Ditto. Came across this in larger C-Series back when they were the new kids on the block. What did the coolant look like, or for that matter the inside of the radiator header tank.?
And coolant in fuel tank-normally. pushed both directions once engine is shut down by psi in coolant system.
I don't believe it was fuel in coolant. Cooler failed and had ton of coolant in bottom of hydraulic tank and hydraulic in radiator that it was pushing out of overflow. I will drain some fuel and make sure it is not coolant in there. Just had me worried as the amount of metal in that paste. If you hold magnet over rag after wiping it off it will suck the rag up. Thanks again for the reply's.
Trans coolers will produce same effect.