Theory on fuel in oil.

[MotoWojo]

2.”Using the Torque app, I monitored boost, and manually shifted to try to stay out of boost.”

Why stay out of boost ?

It was just something I tried to see if it would affect the fuel dilution. Between oil changes, which were frequent and all done under warranty, I tried several different things, mostly from comments on this forum. It really is hard to do, at 75+mph on the freeway with any wind at all, it is always in boost in 10th and I would have to drop down to 8th frequently to stay out of boost. It did not make any difference, although I started thinking it might be helping the fuel mileage as the instant mpg readout would improve when not in boost, but when it came time to fill up the tank, it did not make a difference in the calculated mpg. From my experience, if you have an oil-maker, it doesn't matter how you drive it.

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[MotoWojo]

I have posted the reason as to why there is fuel in the oil. I will post again.

Direct injection engines
They build carbon on the intake valve
Since oil goes over the intake valve, have some fuel in it
Like an old fashioned intake, now you have fuel going over the vavles to help keep it clean,
Like a more traditional engine.

Brilliant!
Science at work

Hmm, so the worse the fuel dilution is, the more fuel flowing over the carboned up valves, thus reducing the carbon on the valves, thus reducing fuel dilution?........brilliant.

 

[Dgc333]

I have posted the reason as to why there is fuel in the oil. I will post again.

Direct injection engines
They build carbon on the intake valve
Since oil goes over the intake valve, have some fuel in it
Like an old fashioned intake, now you have fuel going over the vavles to help keep it clean,
Like a more traditional engine.

Brilliant!
Science at work

????????????

How does that statement have anything to do with fuel diluting the oil in the pan?

 

[CB750F]

So, I drive like a grandpa, cuz, I am a grandpa. I try to hypermile it but fail miserably
as this truck I own, seems to suck gas. But, I don't have an oil maker.
So, for those who say you need to WOT all the time otherwise you'll have the gas in
oil issue, your full of it.

 

[JohnnyO]

Just a theory but I wonder if it's worse in trucks that make a lot of short trips? I don't seem to have this problem but my work commute is 20 miles each way and I drive to to our other facility a few times a week which is about 15 miles down the Interstate. Never seen my oil level go up. I'm thinking if the oil gets up to full temp regularly then any gas in it will burn off. I'm not a petrochemical engineer but I stayed at Holiday Inn Express last night. I'm going to change the oil today and I'll see if I can smell any gas in it.

 

[Motorpsychology]

I don’t beat on my truck much but it’s tuned and I have very little if any dilution or fuel/oil blow by.

Those that drive like grandpas just so they can brag about fuel economy could be creating the problem by not letting the motor work. These motors like RPM.

I totally agree, but Ford engineers the truck to run at 1100-1500 rpm: abut where my 13 liter Cummins liked to run in my Kenworth.

 

[McLeadslinger]

I think the 10 speed in the Ranger may have been a mistake or at least ford could remap the factory trans tuning.

I totally agree, but Ford engineers the truck to run at 1100-1500 rpm: abut where my 13 liter Cummins liked to run in my Kenworth.

 

[Motorpsychology]

If the fuel is evaporating or burning off at operating temp, why is the oil rising so dramatically in the dipstick; normal full being between the holes in the hatchmarks, and many here are experiencing levels up into the twist?
Answer: it isn't a linear measurement. A reading above the first twist appears be about twice the normal full capacity. You can demonstrate this at home with a tall drinking glass and a sauce pan. Pour 4 ounces of water in each and notice the level. Now add another 4 ounces to each. The level in the sauce pan rose a little, but the level in the glass is near the top even though both have the same amount of water.

So while it is eye opening, you don't have a gallon of gas mixed in with the oil.

My Theory
The 2.3 EcoBoost four is an open deck design, much like Ford's other Ecoboosts. This means that the cylinders are not attached to the block at the top of the block, or "deck." The advantage of this design is that the block has more cooling volume in a relatively compact overall size, and is lighter. The disadvantage is that the block has less internal structure for rigidity. Added to this that the engine is undersquare, meaning its stroke (94mm)is longer than its bore diameter(87.5mm). Advantage: more torque at a lower rpm Disadvantage: more rocking couple-kinda like when a load of jeans gets plastered to one side in your washing machine and it rocks during spin dry.
"Twin scroll" means that there are low rpm and high rpm turbocharger fans. This gives higher boost off idle and virtually eliminates turbo lag. Direct injection allows the turbos to only need to pump air, rather than denser air and fuel, so the more air that can be pumped into the cylinders, the more fuel that can be added by the injectors, raising the power output.

Almost done.

This motor has a relatively high (for an everyday turbocharged engine) compression ratio of 10:1. Have you ever hand pumped up a bicycle tire to 65 psi? Try it. That's about 4:1 compression. The low side turbo packs more volume in at off-idle, the injectors add fuel, and because of the undersquare design, the highly pressurized mixture is spending more time in the cylinders per cycle than in an oversquare (larger bore shorter stroke) motor before being ignited, hence more time per cycle for fuel to bleed past the rings. Haven't thought about those, would dual compression rings help? Anyway, all that cacophony is flexing the open deck block.

So what have we got? A less rigid open deck block with an inherently rocking-coupled undersquare displacement being pumped up with a pressurized air-fuel mixture. What could go wrong?

Call me crazy but I bought a 10yr 125,000 mile extended warranty.

 

[Motorpsychology]

I think the 10 speed in the Ranger may have been a mistake or at least ford could remap the factory trans tuning.

Might be to get every last 1/100th mpg out of the the artificial EPA economy testing regardless of real world drivability.

 

[Dgc333]

If the fuel is evaporating or burning off at operating temp, why is the oil rising so dramatically in the dipstick; normal full being between the holes in the hatchmarks, and many here are experiencing levels up into the twist?
Answer: it isn't a linear measurement. A reading above the first twist appears be about twice the normal full capacity. You can demonstrate this at home with a tall drinking glass and a sauce pan. Pour 4 ounces of water in each and notice the level. Now add another 4 ounces to each. The level in the sauce pan rose a little, but the level in the glass is near the top even though both have the same amount of water.

So while it is eye opening, you don't have a gallon of gas mixed in with the oil.

My Theory
The 2.3 EcoBoost four is an open deck design, much like Ford's other Ecoboosts. This means that the cylinders are not attached to the block at the top of the block, or "deck." The advantage of this design is that the block has more cooling volume in a relatively compact overall size, and is lighter. The disadvantage is that the block has less internal structure for rigidity. Added to this that the engine is undersquare, meaning its stroke (94mm)is longer than its bore diameter(87.5mm). Advantage: more torque at a lower rpm Disadvantage: more rocking couple-kinda like when a load of jeans gets plastered to one side in your washing machine and it rocks during spin dry.
"Twin scroll" means that there are low rpm and high rpm turbocharger fans. This gives higher boost off idle and virtually eliminates turbo lag. Direct injection allows the turbos to only need to pump air, rather than denser air and fuel, so the more air that can be pumped into the cylinders, the more fuel that can be added by the injectors, raising the power output.

Almost done.

This motor has a relatively high (for an everyday turbocharged engine) compression ratio of 10:1. Have you ever hand pumped up a bicycle tire to 65 psi? Try it. That's about 4:1 compression. The low side turbo packs more volume in at off-idle, the injectors add fuel, and because of the undersquare design, the highly pressurized mixture is spending more time in the cylinders per cycle than in an oversquare (larger bore shorter stroke) motor before being ignited, hence more time per cycle for fuel to bleed past the rings. Haven't thought about those, would dual compression rings help? Anyway, all that cacophony is flexing the open deck block.

So what have we got? A less rigid open deck block with an inherently rocking-coupled undersquare displacement being pumped up with a pressurized air-fuel mixture. What could go wrong?

Call me crazy but I bought a 10yr 125,000 mile extended warranty.

After having been on the Ecoboost Mustang forum for the past six years and never hearing of this rising oil level issue I have to say that it's not something inherent to the 2.3 Ecoboost engine design.

 

[Motorpsychology]

After having been on the Ecoboost Mustang forum for the past six years and never hearing of this rising oil level issue I have to say that it's not something inherent to the 2.3 Ecoboost engine design.

Allow me to lean heavily on my heading, "Theory" ?.

I can't explain it other than the 2.3 Mustang application has a 9.5:1 compression ratio, but the same bore & stroke. Maybe the Ranger's higher compression is juuussst high enough to weep fuel past the rings? The hp and torque are tweaked differently, too yet as you say, there isn't a chronic fuel-in-oil issue in these nor the Explorer application. Don't know what else could account fo it other than the Ranger's lower power to weight and lower rpm tuning.
edit: correction, higher PTW.

 

[N. J. Jim]

Reserved for sarcastic remarks.

I farted while changing my oil didn't smell fuel anymore!

 

[Dgc333]

Allow me to lean heavily on my heading, "Theory" ?.

I can't explain it other than the 2.3 Mustang application has a 9.5:1 compression ratio, but the same bore & stroke. Maybe the Ranger's higher compression is juuussst high enough to weep fuel past the rings? The hp and torque are tweaked differently, too yet as you say, there isn't a chronic fuel-in-oil issue in these nor the Explorer application. Don't know what else could account fo it other than the Ranger's lower power to weight and lower rpm tuning.
edit: correction, higher PTW.

Static compression ratio doesn't really tell you anything about the cylinder pressures when the engine is running, dynamic compression does and that is determined by the cam timing. The Mustang makes more HP and significantly torque which indicates the cylinder pressures would be higher in the 2.3 Ecoboost Mustang engine.
Also, the Ecoboost Mustang with an automatic transmission runs down below 1500 rpm when cruising just like the Ranger.

 

[JasonTremor]

Did a little parts catalog surfing. The ranger and mustang Ecoboost share the same high pressure fuel pump, but the fuel injectors appear to be a different part number.

Mustang injectors
Part #: CM5279 (9F593)

Mustang Hpfp
Part #: 9350
Fuel Injection Pump-Engine

Ranger injectors
Part #: CM5294 (9F593)
Fuel Injectors and Pipes

Ranger Hpfp
Part #: 9350
Fuel Injection Pump-Engine

 

[Motorpsychology]

Static compression ratio doesn't really tell you anything about the cylinder pressures when the engine is running, dynamic compression does and that is determined by the cam timing. The Mustang makes more HP and significantly torque which indicates the cylinder pressures would be higher in the 2.3 Ecoboost Mustang engine.
Also, the Ecoboost Mustang with an automatic transmission runs down below 1500 rpm when cruising just like the Ranger.

Well this pretty much eliminates all possible reasons why there is fuel in oil. Most everyone in the big Fuel In Oil thread that have done an oil analysis seem to be at 5% dilution or less. I don't know if there is a similar thread for EcoBoost Mustangs but it would be interesting to compare.

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