Coolant on glow plug?

12pilgrim

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Replacing glowplugs today.. the passenger rear plug has a brownish wet sludge (coolant..?) on it (i snapped the spade connector off while removing). This is also the corner where the head seems to barely bubble and weep out oil while running. Another GP had a bit of oil on it, I placed them side by side in the pic to show how brown the sludge is compared to black oil..

Truck runs perfect! I have the radiator out right now and it's being recored.

What would you do/test next? Crank it with plugs out and see what happens?
 

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Jesus Freak

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I feel for you Pilgrim, but without pulling the head, I don't know.
Since it's a 6.9, it ought not to be cavitation, if it is a 7.3....it might be cavitation. If so PM me, and we'll cry together.

So here's some emotional support:
I believe in you! You're good enough, you're smart enough, and GOSH DARN IT!!! People like you!
 

12pilgrim

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I feel for you Pilgrim, but without pulling the head, I don't know.
Since it's a 6.9, it ought not to be cavitation, if it is a 7.3....it might be cavitation. If so PM me, and we'll cry together.

So here's some emotional support:
I believe in you! You're good enough, you're smart enough, and GOSH DARN IT!!! People like you!
That actually helped!! I feel better now. It's a 6.9
 

david85

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That brown stuff could simply be rusty water trapped between the glow plug and the casting of the head. Rain water sometimes gets to the rear of the engine, since that's where the hood joins to the cowling. To me, it looks like the oil is getting in from the outside, not from the combustion chamber. Also note how the tips look dry with what appears to be a good combustion pattern. Looks healthy to me.

As for oil on the rear of the engine? That's harder to pin down, but there are no high pressure oil passages that go between the block and head; everything gets pumped up through the push rods. Oil leaks at top the rear of the engine are more likely to be from the intake manifold gasket (AKA "Valley Pan"), CDR valve, or oil pressure sensor.

Were you getting any coolant pushed out through the expansion tank? Was it also foaming up? Those are the tell tale signs of a head gasket failure. If your coolant level is stable, then yo don't likely have a HG problem.
 

12pilgrim

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I was leaking coolant but not sure if it was into the cylinder since the radiator was definitely leaking, it's being recored now ($1100..). No bubbles or foaming in the coolant or combustion gases according to the harbor freight purple dye tester. The system would hold pressure after running, as in opening the radiator cap it would overflow even a week after driving it and the top coolant hose was pressurized.

That's encouraging about the glow plug tips. They all looked like that and some had some rust on the tops of them, perhaps from water leaking into the engine compartment like you suggested.

Is there a test you would recommend to further diagnose? I may have a 600mi tow in a couple months just below the GCVW of 14k lbs.

Thanks for the help guys.
 

ROCK HARVEY

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The oil you’re seeing could also be diesel fuel from leaky return hoses. I’d also check the drain at the back of your valley pan to make sure it’s clear and not clogged up with debris.
 

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