N14 sudden oil consumption with a topend knock

Bent connecting rods? Did you change the whole cylinder pack or just rod?

 

I could see a valve not sealing causing oil consumption, but I don’t think a injector would.
Maybe @OLDSKOOLERnWV @Dino soar have some thoughts. They run older 855’s

 

Maybe the injector was/is bad and caused the piston top to crack. Been down this trail with two of them. Both were customers of mine so I don’t know a lot about the history but that it was almost 100 percent caused by injector problems.
The blowby was excessive on both to the point it was actually blowing oil out the blowby tube under heavy load.
Maybe a turbo problem to. I had a plastic sac get sucked into an air filter once and covered a large portion of it. The turbo was pulling oil past its seal because there was to much restriction. It’s easily seen by removing a boot from the turbo side of the intercooler. Turbo may be fine in this situation.
I highly doubt it’s valves if it came on fast like you said

 

A bad injector washing down a cylinder wall is possible, but other signs should be visible now.

 

That oil pressure sounds low…..


Smoke on initial cold start up?

noise?

check the air intake to see if turbo is bypassing?

any oil in the fuel tanks making the fuel look dark?

excess oil in the air tanks?

if the cylinder is scarred bad for any reason you will probably hear a tapping noise towards the top of the engine.

Oil thinned out front fuel?

Lot of little things to look at, we can’t see it, but if we could we could possibly give better answers….

 

Most likely will see unburnt fuel running out of the exhaust manifold joints or gaskets at each port. It’s going to be really black and stains everything most people mistake it for oil.
Might also be able to pick up diesel fuel in the oil on a test. Might have something to do with the lowish oil pressure