6% fuel in oil - scared for my injectors

[npauli]

Changed oil recently and just got the oil analysis back:
6% fuel in oil
viscosity down to 13.0
everything else was flawless

10k on oil
Rotella 5W40 (the old kind, before T6)
Bio use varied between 0-15% or so

So injectors are the first thing to come to mind. If I've got a bad injector, how much fuel in oil will I see, and how fast?

Could this much fuel in oil be expected for 10k miles, considering that this 10k included all winter and some very very light duty use? (I really go easy on the go pedal for good fuel economy). If that's the case, I just need to change oil sooner, right?

What would you do, and when?
1) keep an eye on oil level and pressure
2) Take another oil sample sooner (maybe 3k or so) and start watching the trend
3) Have injector balance & return rates checked. Can any indy shop do this, or just dealers?
4) Start planning for the worst

[Mark Rinker]

Start running a quality fuel additive;
Change to a 5K oil change interval, until problem is resolved;
If no smoke, no diesel knock, no visible 'making oil' (most likely spotted at >=20% dilution, in some cases even worse with no engine damage...)...RELAX!

[madmatt]

Balance rates can be checked using different scanners and software. I can do it using my efi live, snap on solus pro or the tech 2. Any shop with a good scanner should be able to do this for you. Also they'll want to max out the rail pressure and see what the actual rail pressure is.

[More Power]

There are a lot of fuel return line banjo fittings beneath each valve cover in an LB7. A leaking fitting or a defective fuel return line could also produce this problem.

Jim

[Kennedy]

Are you or have you ever run any sort of chip on this truck and which one(s)?

[npauli]

Thanks for the feedback guys.

Mark - I've been using PowerService (white bottle) in the winter but nothing in summer. I'm shopping for a good lubricity & detergent additive.

Kennedy - No tuning of any kind.

I'll see if my uncle can read balance rates, etc. with his scanner next time I stop by his shop. Oil analysis is cheap compared to replacing anything (even the oil), so I'll probably just keep checking the dipstick and pulling samples for a while to get a feel for the rate I'm making oil.

[Mark Rinker]

I'd hit it with some heavy doses of FPPF, Howes, etc.

I have successfully freed up sticky injectors on more than one LB7 by running 1qt of ATF per tank for two or three tanks, but some people will scold me for doing so, here. Never had any bad outcomes.

Maybe you'll get lucky and your dribbler will start spraying again.

[madmatt]

At the dealership we had a fuel system service that i cured several balance rate issues with. Check with your local dealer and see if they have a similar system available. Ours actually disconnected the fuel lines too and from the tank and then ran a concentrated cleaning solution through the system. worked great!!

[npauli]

Update:
I've got 2k miles on fresh oil, and just did another oil check: 3% fuel this time. That doesn't sound like a good sign. With warmer weather and no bio, I was hoping the rate of fuel going in oil would slow down or stop (I got 6%/10k on the last oil).

My next steps are:
1) I'm going to try a fuel system cleaner - they've got a new one at work (CAT) that sounds like it might be worth a shot.
2) I'm going to bring the truck into the shop for a checkup. Remind me again what can and should be checked?

injector balance rates (at low idle?)
command rail pressure to max and see what you get?
measure return rate via bucket & stopwatch right? At low idle? Disconnect at the cooler?