Fuel Dilution of Oil - Ecoboost

[Jeff D.]

My '24 Ecoboost is the first DI engine I've owned. I've not experienced fuel diluting the engine oil previously with my other vehicles. At least, that I was aware of.

I live close to work and go home for lunch every day, so have four very short trips each weekday. I don't do many other longer trips regulaly. We had a recent cold snap where temps were below zero many days in a row. During that time I often started my truck via the app to let it warm up before I went to work or went home.

I checked my oil on Wednesday and found the oil level had risen slightly above full mark on the stick and it did smell of gas. This is the first time I've found that on my Maverick.

Because of this I had the oil changed yesterday. I only had two months and 1300 miles on the oil but did not want to have oil diluted with gas, to the extent mine was, in the engine.

Perhaps a little road trip would burned off the gas, but I preferred to spend the money and know the oil is not compromised. I won't change my habits and I am not going to walk to work at -15F or not go home for lunch, nor am I selling my truck for a non DI vehicle, but I will monitor the oil more closely and will greatly reduce the oil change intervals if needed.

I know I've only my nose and eyeballs determining my oil's condition and no OA or scientific data, so can hardly back up my "gut feeling" on this, but it is enough evidence that I feel my concern is not unfounded.

Thought I would share in case others had similiar driving habits to mine, had extreme cold snaps and an Ecoboost may consider monitoring their oil more closely.

Sponsored

 

[Tbone289]

I know I've only my nose and eyeballs determining my oil's condition and no OA or scientific data, so can hardly back up my "gut feeling" on this, but it is enough evidence that I feel my concern is not unfounded.

Your nose can detect minute amounts of fuel in oil. I smell fuel in my Maverick's oil every time I check it, but I've done oil analysis at each oil change, and there is never more than trace amounts in the results. I've also smelled it and could swear the oil level had risen, again with a perfect oil analysis result. Oil level varies from one check to another depending on the conditions, e.g. , temperature of the oil in the pan when checked, temperture of the oil when you shut the engine down, slight variations in f/r level, etc.

My advice is to have oil analysis done next time so that you can put your worries to bed. Stop relying on your nose; it is not a tool capable of determining fuel dilution in oil. I've been driving Ford DI vehicles for 13 years (Duratec and Ecoboost), and have never had more than a trace (unmeasureable) amount in the oil at analysis, yet I could smell fuel in the oil.

 

[Rob911]

Might not be necessary to change your oil, normally if you take a longer drive, say for an hour, or even in town, stop and go, for a hour to let the oil get up to full operating temperature and stay there for awhile the fuel and water will burn off and you'll be fine. I had a similiar problem with my CRV, so once a week, especially int he winter I would start it and let it run for 30 minutes in the driveway and then go for a 45 minute "sunday drive". This always kept the oil at the correct level.

 

[dhaskit]

Jeff,
You did exactly what you should have done.
Monitoring the oil level and quality for the likelihood of fuel or antifreeze contamination and performing more frequent oil changes is exactly what you need to do.

Some degree of fuel passes by the rings and into the oil everytime the engine runs, albeit a very small amount. During cold conditions and short run cycles the engine may not produce enough heat to vaporize the fuel in the oil.
With piston aircraft engines, we try to make it a point to run them long enough on the ground to get our oil temps up well into the normal range. Since the fuel has a much lower vaporization temp, this helps to reduce the fuel that may be in the oil sump.
Your’s is a case of Driving it more will help.

If you are really curious, you might consider sending a sample to Blackstone for analysis but it’s really not necessary.

 

[Glen Baker LLC]

Would an oil catch can, be a good solution for the OP's situation?

 

[Tiger Dude]

Would an oil catch can, be a good solution for the OP's situation?

An oil catch can only solves the problem of oil build-up on the valves (if you think that's a problem). DI engines have differently designed piston rings due to supposed washing of the oil film more by the gas injection. I really don't think it's a problem in newer engines by reputable companies (yes including Ford).

 

[Glen Baker LLC]

An oil catch can only solves the problem of oil build-up on the valves (if you think that's a problem). DI engines have differently designed piston rings due to supposed washing of the oil film more by the gas injection. I really don't think it's a problem in newer engines by reputable companies (yes including Ford).

Thank you for your reply.
I know oil catch cans have been around for years.
I wonder, if the reengineering of the intake of the 2025s will help with less oil dilution?
Hopefully it'll help keep the valves cleaner

 

[Probity]

My '24 Ecoboost is the first DI engine I've owned. I've not experienced fuel diluting the engine oil previously with my other vehicles. At least, that I was aware of.

I live close to work and go home for lunch every day, so have four very short trips each weekday. I don't do many other longer trips regulaly. We had a recent cold snap where temps were below zero many days in a row. During that time I often started my truck via the app to let it warm up before I went to work or went home.

I checked my oil on Wednesday and found the oil level had risen slightly above full mark on the stick and it did smell of gas. This is the first time I've found that on my Maverick.

Because of this I had the oil changed yesterday. I only had two months and 1300 miles on the oil but did not want to have oil diluted with gas, to the extent mine was, in the engine.

Perhaps a little road trip would burned off the gas, but I preferred to spend the money and know the oil is not compromised. I won't change my habits and I am not going to walk to work at -15F or not go home for lunch, nor am I selling my truck for a non DI vehicle, but I will monitor the oil more closely and will greatly reduce the oil change intervals if needed.

I know I've only my nose and eyeballs determining my oil's condition and no OA or scientific data, so can hardly back up my "gut feeling" on this, but it is enough evidence that I feel my concern is not unfounded.

Thought I would share in case others had similiar driving habits to mine, had extreme cold snaps and an Ecoboost may consider monitoring their oil more closely.

You're doing what you can. You're already ahead of most folks in that you know that you have a problem (your short-trip driving regimen and MN winters). There are no quick 'fixes' I know other than what you're doing. Are your injectors 'leaking' excess fuel? Doubtful but who knows.

Many people (me included) have done deep dives into potential small displacement forced induction DI-only engine issues including fuel dilution of motor oil, lots of things come up - low speed pre-ignition (LSPI), calcium and low sulfated ash % detergents of motor oils used, NOACK volatility, catch-cans, ad infinitum. People do this and come up with opinions and conclusions they've drawn, at the end of the day it's like what is said about opinions, they are like that certain anal orifice, everybody has one.

A couple of consistent things also always come up - for your driving regimen, more frequent oil changes with "good' quality oil (however you want to define 'good'), and if you can, occasionally do some longer drives and let those ponies run. You're already doing the more frequent OCI.

I live in a (generally) mild southern climate (although it was 12 deg. F a month ago), my drive routine is also a majority of short (5 mile or less) trips, harsh engine conditions for sure. I purposely got vehicles with engines that are better at dealing with my 'severe service' regimen - one a naturally aspirated (N.A.) MPFI-only grocery-getter, the other a N.A. combo DI/MPFI one. Even so I change the oil more frequently than is called for by the intelligent oil life monitor and/or owner's manual service interval guidelines. So far so good.

I struggled some deciding which nominal 1/2 ton new truck to get a year ago, my major considerations were ergonomics (need a bench seat for back/nerve pain issues), lowest practical purchase price and mpg (I don't drive much). Reluctantly I ended up with a small displacement forced induction DI-only engine, knowing that for grocery-getting/putting around town duties it was probably the worst engine choice - however I don't use it for frequent short trips, and I still change the oil/filter on it more frequently thanmy IOLM calls for. So far so good.

 

[Jeff D.]

Thanks everyone for all the tips and great information. Much appreciated.

A couple of consistent things also always come up - for your driving regimen, more frequent oil changes with "good' quality oil (however you want to define 'good'), and if you can, occasionally do some longer drives and let those ponies run. You're already doing the more frequent OCI.

I did switch from Pennzoil Ultra Platinum Full Synthetic to Valvoline Full Synthetic, but the only reason was due to what the oil change place sold and not because of any unhappiness with Pennzoil. I have always been happy with them.

I don't know much about Valvoline, but assume they must make a decent oil?

Maybe I should do an OA next time I believe the oil may be diluted, just to see? Might be next winter, now, though, weathers warming up and extended warm-up time gone. Normally I am moving (slowly) within 30 second of the vehicle starting.

 

[Tbone289]

Would an oil catch can, be a good solution for the OP's situation?

No, a catch can traps oil and crankcase vapors circulating through the PCV system. Fuel dilution is caused by fuel passing by the cylinder rings and into the crankcase.

 

[Tbone289]

Maybe I should do an OA next time I believe the oil may be diluted, just to see? Might be next winter, now, though, weathers warming up and extended warm-up time gone. Normally I am moving (slowly) within 30 second of the vehicle starting.

Yes, you should. $30 is money well spent to know if your suspicions are correct or not. That $30 could easily save you the price of an oil change next time.

 

[Fcnrwy]

Since, the Mav is my first DI engine. I have been keeping a eye on this subject, on this forum.
My Job changed locations about a year before I got my Mav. (which was Dec. 2022).
Instead of 110 miles per week work and back (5 days), it is now "10"miles per week...

I try to do some "sunday driving" at least three days, on the way home from work to pack on the mileage.
Expressway driving is a major part of this milleage.
(as a late Mechanic friend advised...) I need to "Blow-out that Carbon". Every once in a while.
One of my favorite Home Centers (Menards) is located in the next suburb. So, a trip to Menards is a 25 mile round trip.

Jerry

 

[Jeff D.]

In the pic below of the Maverick dipstick there's three points, A, B & C. I assume B is full and the distance from A to B would be one quart? If B is full (5.5 quarts) C would appear to be approx 1/4 quart more.

I believe my truck was at B the second to last time I checked it and it was at C when I last checked it.

0.25 quart (gas?) / 5.5 quarts (oil) = 4.5% fuel dilution.

That's pretty high, no?

Or, is there too many assumptions in my thinking?

 

[Tbone289]

Yes. Too many assumptions. I see my oil level fluctuate that mulch regularly, and have no dilution issues. I mentioned earlier a few causes of this. It's every unlikely it's anywhere near that percentage.

How's your fuel mileage, and how is it running? That's a LOT of fuel that would show multiple symptoms.

You have it in your head that DI engines regularly have this problem and they really don't.

 

[Carlitos_92]

In the pic below of the Maverick dipstick there's three points, A, B & C. I assume B is full and the distance from A to B would be one quart? If B is full (5.5 quarts) C would appear to be approx 1/4 quart more.

I believe my truck was at B the second to last time I checked it and it was at C when I last checked it.

0.25 quart (gas?) / 5.5 quarts (oil) = 4.5% fuel dilution.

That's pretty high, no?

Or, is there too many assumptions in my thinking?

Your math is fine, but there is zero evidence that says the .25 qt there is fuel in the oil. As Tbone said, your nose will deceive you.

Keep checking the oil to watch it over time. At the next change, send a sample off for testing. Relax and enjoy your truck.

Sponsored