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Bombdropper · 05-15-2022, 03:37 AM

Engine specs:
C15 ACERT
Single turbo conversion
Custom tune
9 month old injectors
9month old interior harness

Coming back from NC and while checking my oil post trip I noticed that the level had gone up. Can’t smell well from military service so couldn’t smell fuel but also saw that it was super clear. Motor runs very well and the oil has been pretty clean for a diesel for months. I decided to get some fuel dye and a black light, poured the dye directly in fuel filter, ran it for 30 seconds and found fuel splattered all throughout the head. EVERY single one for had dye and dye was splattered through the head.
Also when I start it up there is a small plain of grey smoke song with Jake brake a small amount of grey smoke.
Took it to Kenworth unfortunately (my mechanic can’t get it in for 2 weeks) and they said it was a bad fuel pump which is also brand new. Die pump makes absolutely NO sense to me. Anyone have any thoughts on what to look at or did I just have every single injector go bad?

Viking257 · 05-15-2022, 05:25 AM

Had that happen with a company truck in my working days. Oil level went up, diesel fuel smell from dip stick. Mechanic said it was injectors. Don't know if it was 1 or all of them. They fixed the trucks and I drove em.

BillJinOR · 05-15-2022, 06:02 AM

Yes , injectors or “injector” bad. Our leased Penske tractor started gaining oil on our checks .. had to have the injectors replaced. Who did your injectors ? I’d be asking them.

Bombdropper · 05-15-2022, 06:03 AM

Can the fuel pump push fuel past the injector solenoid? That is what Kenworth is saying. Seems impossible to me! I’m saying injectors like everyone else would but didn’t know if there is something else I’m missing.

TandW · 05-15-2022, 06:08 AM

If injectors are suspect an IR gun may help to pin down which ones. Your results may differ.

Caliber · 05-15-2022, 07:51 AM

Quote:

Originally Posted by Bombdropper

Can the fuel pump push fuel past the injector solenoid? That is what Kenworth is saying. Seems impossible to me! I’m saying injectors like everyone else would but didn’t know if there is something else I’m missing.

No, what they are saying is the seal on the fuel transfer pump shaft is leaking fuel back into the crankcase.

Bombdropper · 05-15-2022, 09:46 AM

Ok I see what your saying. Still confused about the grey smoke though. Seems to coincide with the diesel in the oil. Maybe the thinning oil is making it past the injector seals? I appreciate everyone chipping in btw.
How do you test a bad fuel transfer pump? Thought they either worked or they didn’t?

Cat · 05-15-2022, 06:06 PM

Could be be fuel pump shaft seal. If after a injector change you get fuel in oil its normally because a injector mounting seal gets cut. This is done when pushing the injector in. Thining out can cause engine smoke. But be very careful driving any further. Thin enough oil that allows it to smoke can be very harmful to the engine crankshaft bearings and or turbo bearing. To to confirm no damage has been done-- I would remove then carefully cut open the engine oil filter. Then cut out several filter pleats and squeeze then examine the pleats for metal. There should almost no metal in filter pleats. Maybe one small piece pinhead size or smaller per 5-8 pleats. If you have metal- nonmagnetic would be from bearings- brass colored turbo bearing. I would have the techs check the filters before replacing parts. Nothing worse than putting new parts into to a badly damaged engine.
If you have to drive the RV make sure to drain and put fresh oil into engine and keep a sample of the used oil for testing and the filter if changed of course.
I'm not saying the engine has been damaged but just to check before going much further with repairs.
Safe Travels

Bombdropper · 05-16-2022, 04:34 AM

Yeah my mechanic said the same thing and definitely will do. Already bought new bearing kit from Cat and it’s getting them installed end of the month. Never hurts to check oil filter though. Thank you everyone for their input. Will give an update when it’s back on the road

Cat · 05-16-2022, 09:12 AM

Quote:

Originally Posted by Bombdropper

Yeah my mechanic said the same thing and definitely will do. Already bought new bearing kit from Cat and it’s getting them installed end of the month. Never hurts to check oil filter though. Thank you everyone for their input. Will give an update when it’s back on the road

Good luck

Bombdropper · 06-07-2022, 06:32 AM

Truck was diagnosed at the shop and it was the fuel pump. Did an oil sample for testing as I always do before oil changes and this oil is still SUPER clean. It never gets very black even after 10,000 miles and I’m worried something is still wrong. Good power, average fuel economy, and seems to purr as she should so we will see. Drive her till she blows…as my mechanic always tells me ��