I don't post a bunch on here, but I have been coming on here a lot more since buying my 2014 F350. I've done thread searches and read what's out there about the lube oil getting fuel dilution. Problem is I find one group talks about getting an oil analysis, and then the other says it's not needed. And I also read strong opinions about just how much fuel dilution is acceptable while others say it's doom and gloom. Wow!

Here's my situation. After buying the truck, I checked the oil level for a while to make sure it wasn't burning oil, and then I didn't check it as often. Then last Wed I checked the oil level before taking the truck in to have front driver's side weak spring replaced and a section of leaking exhaust pipe replaced. Much to my surprise the oil was up onto the cable! Dealership wasn't concerned, but I changed the oil Sat & put in some Motorcraft 15w-40 just to hedge my viscosity a little since I anticipate the possibility of more dilution. (I realize this doesn't resolve the dilution of the oil's additives.) Used oil came out very thin, and I pulled out 14-1/2 quarts. By volume, that's about 10% fuel to oil. Truck has about 4,000 miles since last oil change by the dealership that I bought it from.

Usage is daily driving to work when I can't drive my GT500 on nice days, and my commute is only 15-20 minutes. I get about one regen a month, and I typically get a couple unfinished cycles going to work before I get one coming home. Then I keep driving out the road for another 20-25 minutes to let it finish. Although, I confess I don't have "proof" that it's finished because I don't have an aftermarket gauge yet, but an extra 20 minutes should get it done. Plan on picking up a device that plugs into the OBDII port to talk with my cell phone for this purpose.

I don't idle the truck much at all, but looking at the system specs I can see the previous owner must have because truck has a little over 700 hours with almost 300 hours idling. To combat this dilution, I will plan on hooking up to my 27' enclosed car trailer (maybe with the car in it too) at least once a month and take a drive to include some hill pulls. That should get some pressure and heat on the engine. I wish there was a way to force a regen after the first incomplete cycle that I get going to work.

So smart guys, how bad is this...really? I cringed at seeing the thin oil that came out of her. I realize I'm setting myself up to hear more of what I've read on other threads, but I'm hoping some of you will have words of wisdom that I'll recognize as being based in fact.

Thanks!

 

Short drive cycles and multiple unfinished regen cycles will help add to the fuel dilution problem.

If you continue the drive pattern just monitor what's going on. If you change the drive pattern to longer trips and working the motor a bit more you'll probably see a decrease in the amount of fuel present in the oil. If that doesn't change or if it gets worse, only then will there really be cause for concern.

 

If you are concerned I would do a UOA. Blackstone is one place that will do them. It provides a wealth of information about your motor, including the actual fuel dilution %.

You may want to do one the next time. If it isn't really high, you should take the truck in to make sure you don't have a stuck injector. I'd also keep an eye on my coolant level - which could indicate an issue as well. Although blown head gaskets are rare on stock power level 6.7s - anything is possible.

I also agree wtih Curtis, but since at times I have been the king of short trips and haven't noticed a huge increase in oil level on either of my several 6.7s after I properly monitored them, which is why I would at least like to rule out the above potential issues. Granted, no two people use their or drive it the same way, so it's entirely possible your use is putting fuel in the oil as Curtis said, in which case the only thing you can do is change the oil sooner.

 

Drive it more would be my answer with longer intervals. 15 to 20 minutes is really not enough time to bring the temps up to snuff for a period of time. I have suspected a lot of raw fuel gets into the Engine oil when the engine is cold or cool. Pull with it will also make a difference. I have found these engines want to work, not idle which is essentially what it is doing at 70mph on the hiway empty. There is not much load there and these engines like to pull. Now that I have a Sport Trac as my daily driver, my 6.7 is only used to pull the 12k 5er. The past oil change, after 6k pulling miles, I drained 13 quarts. Where before when it was my daily driver, I would drain and get right at 14 quarts. I never really thought twice about it. Of course again as stated we all drive different, each engine is different and what part of the country we live makes a difference.

 

Thank you for the replies!