Do you guys ever see your oil level go up? I know with DI gas engines that's very common, usually from fuel condensing on the cylinder walls at cold startup. Not sure about our diesels but I assume being direct injection that is a possiblity.

I'm honestly just starting to pay attention to this with my truck. On the last oil change I set the level at mid dipstick with new oil. Around 4k miles it was up to the full mark. I got nervous and changed the oil and sent a sample to Blackstone and it showed 2% fuel dilution. My normal commute is 6-miles each way so the truck gets a lot of short trips which I'm guessing is the cause. I'm about 4k on the current oil change and the oil level is back up at full.

It does usually get up to 190F ECT and EOT by the end of the commute at least, even during the winter as I garage it.

I did a 500-mile trip to the desert last winter towing my trailer. At 10mpg ran thru a bunch of fuel and had some long climbs at high boost. I checked oil level before/after and it was the same so I'm thinking its not an injector issue.

 

2004 F350. It was working daily, fair amount of idle time, commercial / industrial / towing / off road use. I used 5,000 kilometres / 3,100 mile intervals. Motorcraft filters. Egr delete, everything else stock. RT 15/40 at first, switched to RT6 5/40 & 0/40. No issues. Only had a couple of oil analysis, reports were good. Truck was traded in @ 355,000 kilometres / 220,000 miles, running well.

Currently I am moving my ‘06 to a 10,000 kilometer / 6,200 mile oci. Personal use, occasional towing/hauling, light off road. No idle time. RT6 5/40. Motorcraft filters. Oil analysis at each change (no issues on last report). All Stock, for now. I am considering the BPD air/oil cooler, but no additional filter.

Oci on the 5’s and 10’s in kilometres work well for me for ease of use and tracking. No matter who is a vehicle, they know it’s time when you hit those numbers. The 2004 was part of a fleet.

 

It can, as you've found with frequent cold starts relative to total miles, or with significant idle time. I'd have to actually go find the book to confirm, but IIRC 6 months use or 200 hours is the equivalent of 5000 miles of driving in the "special" schedule in the maintenance guide. PTO applications, full time heavy towing, delivery, frequent start/stop, etc.

I did do several 3750 mile OCis back when the truck had the original maintenance package on it. I got "free" oil changes at the dealer that I'd pre-paid for, so in the winter when I wasn't driving far but was driving frequent I'd drain and fill halfway through to make sure the oil didn't grow. I was also pretty good about using the block heater before short commute trips, at least the one starting from my house. My power bill was a lot cheaper back then, and hey the truck is still running so maybe it was worth it

I don't go to the point of tracking driving vs idle hours, but I do have a list of total miles vs total hours in my excel sheet. My lifetime average is 47.3 MPH, and if the average doesn't change much I don't figure there's any concern with idle time vs hours and my OCIs. Sometimes I'll idle the truck for 3-4 hours at the ranch to keep the AC running, but when I do that it's normally also the same day I'll do 3-4 hours of driving at 75mph+ on the highway to get there, so for me it all averages out. Plus you can't have a hot-no-start if you never turn the engine off

 

I change every 5k with 5w40 synthetic, have a bit over 355k miles now

Haven’t done oil analysis in quite a while…need to do so again 😬

 

I agree with Bryan that idle time increases fuel dilution and dipstick values. When I was collecting everyone's Blackstone reports at TheDieselStop, it was common to see that.

 

That's pretty much impossible in gasoline engines because the tiny amount of gasoline that could get into the oil completely evaporates once the engine warms up.

Back in the old days, gasoline dilution was common (AND intentional) in radial aircraft engines in extremely cold weather.

Before engine shutdown, the pilot would pull a **** in the cockpit that would allow AVGAS to literally "drain" into the oil, while it was still running mixing it into the oil.

Then the next morning when the temp might be well below freezing and the engine cold soaked.... The oil/gasoline mix was still liquid enough to flow when the engine was cranked and started. Once the engine was warmed up, the gasoline would quickly evaporate out of the oil.

To get enough oil past the rings in a any gasoline engine would likely prevent it from even starting and if it was a flow(of gasoline) , it would cause a hydraulic lock in 1 or more cylinders (risking a bent rod or worse)

Not saying gasoline can't ever get into the oil in a DI gasoline engine but it would have to enter the oil much like a our diesels. a severe leak in a supply or return line to one or more injectors under the valve cover.

But the fuel wouldn't persist for long in a gasoline engine because it would evaporate quickly in hot oil

Diesel evaporates, but at a MUCH slower rate...... And probably would not evaporate much at all at normal engine temps in a diesel engine so it readily shows up in an oil analysis.

I'll also add that gasoline can and and does show up in certain older carbureted inboard and inboard/outboard gas marine engines because the old mechanical fuel pumps can develop a leak in the pump diaphragm. Since they are bolted directly to the block the fuel flows right into the oil.

Cheers,

Rick

Oh, and I always change my oil @ 5000 because it's easy to see on the odometer. I use any good synthetic 5W40 oil as long as it's listed in the FOMOCO oil recommendation publication. (seems the current one is dated 2022)


FOMOCO Diesel Oil reccomendation (opens a PDF)

FOMOCO Diesel Oil position statement (PDF)

 

Those old radial engines are so cool. I can literally hear those things from miles away and start searching the sky. Such an engineering marvel, and massive hp producer. Thanks for the post!!

 

Yup!

And there is nothing like the sound of one starting up!!

 

I sure thought that the oil recommendation list had been updated a few times since 2022. Two years is a long time to not have any updates! Shame on them!

 

Yeah,

They're pretty slow and probably don't really care. Or, maybe the oils haven't changed enough to change the recommendation.

 

It's actually pretty common in modern gas Direct-injection engines. Search the internet for "oil dilution" on modern vehicles and tons of issue pop up. Honda had a huge issue with their 17-18 CRVs with oil dilution, primarily in cold climates:

https://www.wardsauto.com/internal-c...lution-problem

The general thought I've found is from a cold-start with a cold cylinder, rich mixture, gas gets will condense on the cylinder walls and get washed down into the crankcase.

I previously owned a '13 F150 Ecoboost truck and if I only did short trips in the winter (6-7 miles each) the oil level would go up quite a bit (from halfway on the dipstick to full). Go for a long drive (1hr+) and it would come back down.

 

My grandfather was a USMC fighter pilot in WWII , flew the Hellcat with the Double Wasp that (IIRC) should be in that P-47. He said they had a touch more power than the 6-banger in the O-1s he flew in Korea.

Living in Ft Worth with NASJRB FtW (ex-Carswell AFB) right here I love watching the B-47 take-off scenes in Strategic Air Command, had some BIG engines on those.

 

I received my results for the last oil change and a bottle of archoil 9100. The oil sample went a little above 7k but I will also note that this oil change I did not tow anything of significant weight. I never have to add oil to the system, even though I have a small weep from the rear main

I was busy remodeling the inside of the house and spent all last year pretending I knew what I was doing, so no vacations towing the 5th wheel or boat.

Oil used: Mobil Delvac 1™ Advanced Synthetic 5w/30

From Blackstone: This is a perfect report. Wear metals didn't change much over the last oil run, so we don't have any concerns in the wear department. Molybdenum came down, but that was just an additive in the 5W/40 you used last time. Sodium is still low, so no coolant trouble is suspected. The oil read in the right viscosity range for 5W/30 and the high flashpoint rules out any measurable fuel dilution. Insolubles remain low at 0.3%, showing good combustion and oil filtration. Nice results!

Wanted to follow up with everyone.

Thanks
Joe

 

Good deal! Perfect report from an oil not on "Ford's List".

 

Yeah for sure. I am sure had I worked the truck harder like I did in the past it would be a bit different, but nevertheless I am happy with the results.