New o-rings found coolant where it shouldn't be

[takenreality]

About a month ago I replace the injector o-rings at the recommendation of a local diesel tech. When the injectors were installed again the truck's fuel economy went from 16 MPG to 5 MPG. Hauling 1,000 lb over 12,000 ft mountain pass was slightly less responsive, the trip was routine. Truck started and drove mostly norma.

I assumed the injector seals weren't doing their job so out came the injectors again and sent them off to Jim at Rosewood Diesel Shop who was great to work with and very quick. Today I installed the injectors after meticulously cleaning inside the heads where the injectors seals seat (found some garbage in there.) To purge the oil/diesel from the cylinders I hand cranked the crankshaft 10 rotations with the valve covers on glow plugs out followed by kicked the engine over for 20 seconds on the starter. No unexpected resistance. This is when my discovery took place.



To get the truck started I needed to take the covers off and install the rest of the motor. When I pulled the covers off I noticed #2 and #4 had misted coolant on the inside of the valve cover. Potentially it was only #2 and it then stucked into #4 then blew out the next stroke. WTF. Here is the question.

Why did coolant come out of any of my cylinders? Where could it come from?

No oil in coolant I see. Coolant reservoir is clean and green (flushed and reinstalled coolant within 5k miles.) No leaking on ground. No rust on dip stick but haven't drained oil to check that.

Tomorrow I will clean and reinstall the valve cover and check again. Then get a compression tester and check all the cylinders making sure they are withen 10% (5%?) Any other suggestions?

This truck hasn't exactly been what the PowerStroke community would call "awesome", if I am doing a head gasket I am going to be sick...and broke!


Any help and/or experience would be great.

1997 F250 Auto 4x4 233k miles

[takenreality]

Originally Posted by takenreality

Why did coolant come out of any of my cylinders? Where could it come from?

Injector cups perhaps? Anyone know how to test my theory.

[STANGMAN893]

I have seen oil and coolant mix in a 7.3 when the injector cups were bad.was a tiny hairline crack in em after an injector replacement. Look see if any look sketchy.

[codyrock87]

Keep all injectors out and pressure test cooling system 14-16psi. Inspect cups for leaks, should be prettyeasy to tell if they are leaking, if not stuff white rags in cups and let pressure stay on cooling system.

[takenreality]

...cracked cups..

I took photos of all the cups before I installed the injectors and don't see any cracks but the image isn't in perfect focus. Will stick some rags in there and pressurize the system tomorrow.

Another question. These injectors have brand spanking new seals on them I've heard can only be installed once like a head gasket. Do I need to put new seals on my problem injectors now? Coolant is new do I need to flush that again only 100 miles after injectors were first pulled?

I'm psyched to install new cups rather then a head gasket. Is it recommended to replace all the cups or can I buy one for my problematic cylinder? Anyone have the tools for this job I can rent?



not good enough to see cracks...crap

Thanks for a fast response codyrock87 & STANGMAN893.

[BigFuel]

Cousins truck just went down for fuel in the cooling system. Found micro cracks in the cups where the cups transitions/tapers from the mid size to the small size near the base of the cups. Must be thinner material there as a Ford overhaul tech started telling me that this is becoming a bigger and bigger issue on the 7.3's lately. Replaced all the cups and glow plugs because we're there. 200 miles later still good.

[codyrock87]

And yes, anytime the injector is removed the compression washer and all o rings must be replaced!

[takenreality]

Thanks for the help everyone. Just purchased another o-ring set, injector cups, and rented the tools to pop them out and reinstall on eBay. Good video to show how this is done with this tool on youtube. When is all goes back together we will see!

[takenreality]

Pulled a few injector sleeves today. Easy to remove, pain to clean. At the recommendation of local part store substituted Permatex on a couple sleeves. I think that was a bad idea so ordered another cup and Locktite 620. Turns out Locktite brand is thicker, will seal a larger gap, and has a higher temp rating. Unfortunately it isn't available within 100 miles of where I live. If you doing cups order some Locktite is my 2¢. That would have saved me $$ and another week. Do it once and do it right.

[takenreality]

Everything back together truck runs great! Thanks everyone for the help! New cups and rebuilt injectors from Rosewood Diesel got me a 10% fuel economy boost! Without plugging the truck in the starts are much faster also. Now I need to flush the coolant and change the oil and I'm set for hopefully another 230k.