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Discussion Starter · #1 ·
Removed Injectors after a failed Install and I found a problem on 1st injector on passenger side, I had installed Reman injectors on my LB7 after having diesel in my Oil, after a few hundred miles on my new injectors, I noticed a diesel smell and Diesel in my oil, i kinda gave up and parked it for a while. I took it all apart again and I was planning on installing all new injector cups, seals and pressure lines, then starting it with dye in the system and with valve covers off..
after puling all the injector off, I notices a ripped seal on Injector shaft, also noticed Carbon Past the Copper washer. could this have been my problem with oil in the diesel? on one of the pictures attached, you can see the carbon on the nut part of the injector and also the ripped seal. you can also see a lot of carbon on the tip.
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Definitely looks like a way for the fuel to get out but i don’t see how it would get into the oil from there. Are all your piston rings good?


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Discussion Starter · #3 ·
Definitely looks like a way for the fuel to get out but i don’t see how it would get into the oil from there. Are all your piston rings good?
im not sure, truck ran fine before, what's the best way to test for piston issues?
 

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If you have a borescope you could look inside the cylinder through the injector hole and turn the crankshaft by hand and see if theres any scoring or scraping of the cylinder walls. Or do a pressure test of the cylinders. Not sure how to do that. Might need a mechanic for that part.


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A badly leaking copper washer can actually put fuel in the oil but it's more often then not your return lines leaking..clean the injector bores good,use new copper washers and oem return line seals and torque the returns slightly tighter then spec

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The torn o-ring happens quite a bit really. I've seen a TON of them that way. THe copper sealing washer didn't seal, thats why there is carbon getting up into the cup and around the injector there. BUT, that still won't explain where the fuel is getting into the oil. There is either a return line leaking, or a high pressure line letting fuel by and into the oil. Usually you will see fuel leaking on the top of the line nut as well if that is happening though. SO likely a return line gasket didn't seal- possibly from the injector not being seated correctly (also could be the cause of the copper sealing washer not sealing), or a return line being compromised.
 
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