I've got a OBS
7.3 with 80k on a reman engine.
However it burns alot of oil, to the tune of 3 quarts/tank of fuel.
I notice that on most starts, hot or cold, and when leaving a stoplight, there is a fresh "puff" of blue smoke, and then a blue haze while running, hot or cold.
I've done a lot of research on the issue so hopefully the common issues are taken care of/checked off already.
-The o-rings on the injectors have already been replaced, no change. Still clean and green fuel in bowl.
-New turbo and delete pedestal installed, dry exhaust soot in downpipe, not excessive at all.
-Blowby cap test results: no blowby "smoke" comes out with CCV
line open; CCV
line pinched off, some blowby comes out but still not enough to move the cap.
-Actual compression test results on a 40*F (cold, not run in a few days) or so engine:
Truck starts quickly cold or hot and runs pretty smooth. This is my first experience with an OBS
7.3 so I'm not quite sure how smooth it should run, but for a diesel, seems pretty good.
Performance seems very good. I've heard the 7.3s were dogs, but this one seems to go pretty nicely. That being said, I have been chasing a CEL
, just replaced the MAP
sensor, and now it's low on power. I haven't run it in a week since I've been doing compression checks, but I did pull the EBP
tube and clean it out (about 5 inches of it was completely clogged with soot) so hopefully that will fix my low power issue. No CEL
now with MAP
Back to the compression test. I'm wondering why cylinder #5 is so much higher than the rest. It's pretty much at a compression that would be appropriate for a new engine.
My hypothesis for this thing using oil: Number 5 injector is internally worn and allowing oil into the cylinder to be burned. This is also the reason that is has a higher compression because its essentially a wet compression test (oil in the cylinder).
I understand that if injectors are internally worn that it would start hard due to the thinner oil getting past the intensifier piston easier. But with just one injector worn, would it be possibly to have good starting, yet still burn that much oil?
What do you guys think?