4xe FORM fuel in oil

[jameslavis]

so got the form mode after 300km old. stupidly did the oil reset fix but figured it showed 98 percent oil and it’s like a week old

but i did smell the dipstick and it has a gas scent. is this normal? should i run this sucker on the highway?

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[blueweb]

https://mechanicbase.com/engine-oil/oil-smells-like-gas

 

[lindaspins]

From Jeep's post in the Facebook Jeep 4xe Fans group:

Hello All,
We wanted to provide further insight, as we see that there are still conversations surrounding FORM. Our engineers have comprised the following details and we encourage you all to take a look. We have also included the link to the updated Owner’s Manual which now reflects the changes to the section marked “Fuel and Oil Refresh Mode”.

Thanks,
Jeep Cares
Further information on the operation of Fuel Oil Refresh Mode (FORM) in the Wrangler 4xe
What is FORM?
Some customers have commented about repeated or extended incidents of Fuel Oil Refresh Mode (FORM) during the winter season. If this is the first time you're hearing about FORM, please refer first to the owner's manual information: https://msmownerassets.z13.web.core...ler_4xe/P125757_21_JL_H_SU_EN_USC_DIGITAL.pdf
The purpose of this message is to better communicate how the oil dilution portion of FORM works, why some people see it frequently but others don't, and how to get Electric drive mode back. We won't discuss the stale fuel or spark maintenance portions of FORM here, because they are more straightforward and not seasonal in nature.
What is happening in the engine?
Oil dilution FORM exists to reduce the possibility of engine damage caused by contaminants diluted in the engine oil. The contaminant of primary concern is gasoline, since it's continually injected directly into the combustion chamber while running. Although the 2.0-liter turbo 4-cylinder engine in the Wrangler 4xe is manufactured to precise tolerances, piston-ring-to-cylinder-bore sealing varies with engine operating temperature. Sealing is optimized for normal operating temperature. It's normal for some gasoline to make its way past the piston rings when the engine is cold. When the engine becomes warm, the piston rings expand and seal more tightly. Gasoline evaporates out of the hot engine oil, is routed through the Positive Crankcase Ventilation (PCV) system, and is ultimately used to make power.
Is the Wrangler 4xe different from other vehicles?
Oil dilution happens in all internal combustion engines. In conventional vehicles, trips of moderate length are enough to resolve the condition. This is why ICE vehicle owners’ manuals recommend frequent oil changes in vehicles used for short trips. In Plug-in Hybrid vehicles, some use cases lead to many cold engine startups but little or no engine operation at normal temperature. One example is a customer who uses their Plug-in Hybrid Electric Vehicle (PHEV) just like a Battery Electric Vehicle (BEV), except for 0 - 15 minutes' duration ICE operation during most drive cycles. This short engine operation might come during remote start to warm the cabin, or a short high-speed portion of an otherwise all-electric commute. With that type of usage, especially while the outdoor temperature is cold, it's possible for 100% of engine runtime to occur with the engine well below normal operating temperature. Gasoline dilutes into the oil whenever the engine runs, but never evaporates out again. Over time, the contamination level grows.
You won't see features like FORM in BEV's or HEV's, because they're not subject to this use case. But in PHEVs from other manufacturers, you’ll see warnings like "Low Engine Use Mode," "Maintaining Hybrid mode to protect engine," or "Engine Maintenance Mode," which all do the same thing as FORM.
How does the vehicle “know” about dilution? What does it do about it?
It's not practical to directly measure the proportion of gasoline diluted in the oil of a running engine. Before the launch of the Wrangler 4xe, Stellantis engineers built a model which accurately predicts the rate of dilution and evaporation inside the engine. This model runs at all times in the Wrangler's computers, and is based mainly on engine oil temperature, engine load and engine runtime. This is why it's important never to reset your Oil Life Indicator, if you have not changed the oil. To do that would introduce a large error in the modeled vs. actual dilution, and increase the probability of engine damage. Wrangler 4xe owners who encounter dilution FORM have commented that their engine oil smells like gasoline. This indicates that the dilution model is correctly identifying and mitigating a potentially damaging situation.
Dilution FORM in the Wrangler 4xe behaves differently, depending on modeled dilution level.
· Step 0: Normal Operation: Below a bottom threshold, vehicle operation is normal.
· Step 1: Moderate fuel dilution: Between the bottom and middle thresholds, silent start allows electric operation during a drive until the first ICE start. After that, you'll see the FORM message and the ICE will continue running until you shut the car off.
· Step 2: More fuel dilution: Between the middle and top thresholds, EV operation is not allowed. The ICE will start when you power up the vehicle and remain running until you shut down, or the bottom threshold is reached, whichever comes first.
· Step 3: More fuel dilution: Above the top threshold, EV operation is not allowed, and the vehicle will instruct you to perform an oil change.
Depending on outside temperature and how the vehicle is being operated, it could climb or descend this ladder. Based on thorough review of feedback from dealership service departments, directly from customers through Jeep Wave, and from social media postings this winter, Jeep believes some Wrangler 4xe customers' engines are rarely warming fully to operating temperature. For this reason, oil dilution is staying between the bottom and middle thresholds (“Step 1”) for extended periods of time in some vehicles operating in cold climates. The user's experience is therefore similar to frequently leaving and re-entering dilution FORM. Some customers may also be experiencing extended periods in “Step 2.” Jeep Engineering and Jeep Wave are not aware of any cases where FORM is acting differently than designed, or where an unrelated hardware issue is exacerbating FORM duration or frequency.
How can I get Electric mode back?
The use case which leads to this level of dilution can vary, but the path to resolution is always the same:
· Start the engine and allow engine oil to reach normal operating temperature. 169°F (76°C) is the minimum, but normal operating temperature is above 194°F (90°C). Elevated speed and load will warm the engine oil most quickly.
· Continue running the engine until FORM is no longer shown in the Message Center of the instrument cluster. Depending on the dilution level, oil temperature and outside temp, this can take from 20 minutes to 2.5 hours.
· In case the above steps are not possible, change the engine oil and reset the oil life indicator.
· Never reset the oil life indicator without changing the engine oil.
It's possible that some use cases lead to a lot of dilution and not enough evaporation to compensate. In this case FORM will return as long as the weather remains cold. We have high confidence that these frustrations will be resolved when the weather becomes warmer.

 

[jameslavis]

i’ve cruised a ton of forums on this. it’s just a pain. never heard pf
fuel in the oil but never had to pay attention. this will be an interesting ownership.

 

[mllcb42]

i’ve cruised a ton of forums on this. it’s just a pain. never heard pf
fuel in the oil but never had to pay attention. this will be an interesting ownership.

Not uncommon on phevs, turbocharged engines, or direct injected engines. Mix all 3 together and it's even more likely.

You're in form because it's determined there's fuel in the oil and it's trying to do something about it. The oil smelling like fuel is a good confirmation that it's doing the right thing.

Unfortunately, by resetting the computer, you have told it that you put fresh oil in and it's going to behave like the oil is fresh and clean despite you knowing otherwise. The right move right now is to go change the oil since you told it you did.

 

[GATORB8]

From Jeep's post in the Facebook Jeep 4xe Fans group:

Hello All,
We wanted to provide further insight, as we see that there are still conversations surrounding FORM. Our engineers have comprised the following details and we encourage you all to take a look. We have also included the link to the updated Owner’s Manual which now reflects the changes to the section marked “Fuel and Oil Refresh Mode”.

Thanks,
Jeep Cares
Further information on the operation of Fuel Oil Refresh Mode (FORM) in the Wrangler 4xe
What is FORM?
Some customers have commented about repeated or extended incidents of Fuel Oil Refresh Mode (FORM) during the winter season. If this is the first time you're hearing about FORM, please refer first to the owner's manual information: https://msmownerassets.z13.web.core...ler_4xe/P125757_21_JL_H_SU_EN_USC_DIGITAL.pdf
The purpose of this message is to better communicate how the oil dilution portion of FORM works, why some people see it frequently but others don't, and how to get Electric drive mode back. We won't discuss the stale fuel or spark maintenance portions of FORM here, because they are more straightforward and not seasonal in nature.
What is happening in the engine?
Oil dilution FORM exists to reduce the possibility of engine damage caused by contaminants diluted in the engine oil. The contaminant of primary concern is gasoline, since it's continually injected directly into the combustion chamber while running. Although the 2.0-liter turbo 4-cylinder engine in the Wrangler 4xe is manufactured to precise tolerances, piston-ring-to-cylinder-bore sealing varies with engine operating temperature. Sealing is optimized for normal operating temperature. It's normal for some gasoline to make its way past the piston rings when the engine is cold. When the engine becomes warm, the piston rings expand and seal more tightly. Gasoline evaporates out of the hot engine oil, is routed through the Positive Crankcase Ventilation (PCV) system, and is ultimately used to make power.
Is the Wrangler 4xe different from other vehicles?
Oil dilution happens in all internal combustion engines. In conventional vehicles, trips of moderate length are enough to resolve the condition. This is why ICE vehicle owners’ manuals recommend frequent oil changes in vehicles used for short trips. In Plug-in Hybrid vehicles, some use cases lead to many cold engine startups but little or no engine operation at normal temperature. One example is a customer who uses their Plug-in Hybrid Electric Vehicle (PHEV) just like a Battery Electric Vehicle (BEV), except for 0 - 15 minutes' duration ICE operation during most drive cycles. This short engine operation might come during remote start to warm the cabin, or a short high-speed portion of an otherwise all-electric commute. With that type of usage, especially while the outdoor temperature is cold, it's possible for 100% of engine runtime to occur with the engine well below normal operating temperature. Gasoline dilutes into the oil whenever the engine runs, but never evaporates out again. Over time, the contamination level grows.
You won't see features like FORM in BEV's or HEV's, because they're not subject to this use case. But in PHEVs from other manufacturers, you’ll see warnings like "Low Engine Use Mode," "Maintaining Hybrid mode to protect engine," or "Engine Maintenance Mode," which all do the same thing as FORM.
How does the vehicle “know” about dilution? What does it do about it?
It's not practical to directly measure the proportion of gasoline diluted in the oil of a running engine. Before the launch of the Wrangler 4xe, Stellantis engineers built a model which accurately predicts the rate of dilution and evaporation inside the engine. This model runs at all times in the Wrangler's computers, and is based mainly on engine oil temperature, engine load and engine runtime. This is why it's important never to reset your Oil Life Indicator, if you have not changed the oil. To do that would introduce a large error in the modeled vs. actual dilution, and increase the probability of engine damage. Wrangler 4xe owners who encounter dilution FORM have commented that their engine oil smells like gasoline. This indicates that the dilution model is correctly identifying and mitigating a potentially damaging situation.
Dilution FORM in the Wrangler 4xe behaves differently, depending on modeled dilution level.
· Step 0: Normal Operation: Below a bottom threshold, vehicle operation is normal.
· Step 1: Moderate fuel dilution: Between the bottom and middle thresholds, silent start allows electric operation during a drive until the first ICE start. After that, you'll see the FORM message and the ICE will continue running until you shut the car off.
· Step 2: More fuel dilution: Between the middle and top thresholds, EV operation is not allowed. The ICE will start when you power up the vehicle and remain running until you shut down, or the bottom threshold is reached, whichever comes first.
· Step 3: More fuel dilution: Above the top threshold, EV operation is not allowed, and the vehicle will instruct you to perform an oil change.
Depending on outside temperature and how the vehicle is being operated, it could climb or descend this ladder. Based on thorough review of feedback from dealership service departments, directly from customers through Jeep Wave, and from social media postings this winter, Jeep believes some Wrangler 4xe customers' engines are rarely warming fully to operating temperature. For this reason, oil dilution is staying between the bottom and middle thresholds (“Step 1”) for extended periods of time in some vehicles operating in cold climates. The user's experience is therefore similar to frequently leaving and re-entering dilution FORM. Some customers may also be experiencing extended periods in “Step 2.” Jeep Engineering and Jeep Wave are not aware of any cases where FORM is acting differently than designed, or where an unrelated hardware issue is exacerbating FORM duration or frequency.
How can I get Electric mode back?
The use case which leads to this level of dilution can vary, but the path to resolution is always the same:
· Start the engine and allow engine oil to reach normal operating temperature. 169°F (76°C) is the minimum, but normal operating temperature is above 194°F (90°C). Elevated speed and load will warm the engine oil most quickly.
· Continue running the engine until FORM is no longer shown in the Message Center of the instrument cluster. Depending on the dilution level, oil temperature and outside temp, this can take from 20 minutes to 2.5 hours.
· In case the above steps are not possible, change the engine oil and reset the oil life indicator.
· Never reset the oil life indicator without changing the engine oil.
It's possible that some use cases lead to a lot of dilution and not enough evaporation to compensate. In this case FORM will return as long as the weather remains cold. We have high confidence that these frustrations will be resolved when the weather becomes warmer.

Thanks for sharing, usually avoid the FORM threads to avoid all the whining, glad I clicked on this one.

 

[lalalofsky]

Blowby is a huge issues on turbocharged vehicles, direct injection. I have installed a catch can on my jeep to help prevent future carbon build up on the backs of my valves. I did find my oil had a light fuel smell, but i knew going into it blowby was pretty common. In fact, as this is slightly related Chrysler’s standard of oil consumption for a vehicle in its first 50k of life is 1QT for every 2k miles. I was taking the Chrysler training and picked up that not so fun tid bit

 

[sentience]

From Jeep's post in the Facebook Jeep 4xe Fans group:

Hello All,
We wanted to provide further insight, as we see that there are still conversations surrounding FORM. Our engineers have comprised the following details and we encourage you all to take a look. We have also included the link to the updated Owner’s Manual which now reflects the changes to the section marked “Fuel and Oil Refresh Mode”.

Thanks,
Jeep Cares
Further information on the operation of Fuel Oil Refresh Mode (FORM) in the Wrangler 4xe
What is FORM?
Some customers have commented about repeated or extended incidents of Fuel Oil Refresh Mode (FORM) during the winter season. If this is the first time you're hearing about FORM, please refer first to the owner's manual information: https://msmownerassets.z13.web.core...ler_4xe/P125757_21_JL_H_SU_EN_USC_DIGITAL.pdf
The purpose of this message is to better communicate how the oil dilution portion of FORM works, why some people see it frequently but others don't, and how to get Electric drive mode back. We won't discuss the stale fuel or spark maintenance portions of FORM here, because they are more straightforward and not seasonal in nature.
What is happening in the engine?
Oil dilution FORM exists to reduce the possibility of engine damage caused by contaminants diluted in the engine oil. The contaminant of primary concern is gasoline, since it's continually injected directly into the combustion chamber while running. Although the 2.0-liter turbo 4-cylinder engine in the Wrangler 4xe is manufactured to precise tolerances, piston-ring-to-cylinder-bore sealing varies with engine operating temperature. Sealing is optimized for normal operating temperature. It's normal for some gasoline to make its way past the piston rings when the engine is cold. When the engine becomes warm, the piston rings expand and seal more tightly. Gasoline evaporates out of the hot engine oil, is routed through the Positive Crankcase Ventilation (PCV) system, and is ultimately used to make power.
Is the Wrangler 4xe different from other vehicles?
Oil dilution happens in all internal combustion engines. In conventional vehicles, trips of moderate length are enough to resolve the condition. This is why ICE vehicle owners’ manuals recommend frequent oil changes in vehicles used for short trips. In Plug-in Hybrid vehicles, some use cases lead to many cold engine startups but little or no engine operation at normal temperature. One example is a customer who uses their Plug-in Hybrid Electric Vehicle (PHEV) just like a Battery Electric Vehicle (BEV), except for 0 - 15 minutes' duration ICE operation during most drive cycles. This short engine operation might come during remote start to warm the cabin, or a short high-speed portion of an otherwise all-electric commute. With that type of usage, especially while the outdoor temperature is cold, it's possible for 100% of engine runtime to occur with the engine well below normal operating temperature. Gasoline dilutes into the oil whenever the engine runs, but never evaporates out again. Over time, the contamination level grows.
You won't see features like FORM in BEV's or HEV's, because they're not subject to this use case. But in PHEVs from other manufacturers, you’ll see warnings like "Low Engine Use Mode," "Maintaining Hybrid mode to protect engine," or "Engine Maintenance Mode," which all do the same thing as FORM.
How does the vehicle “know” about dilution? What does it do about it?
It's not practical to directly measure the proportion of gasoline diluted in the oil of a running engine. Before the launch of the Wrangler 4xe, Stellantis engineers built a model which accurately predicts the rate of dilution and evaporation inside the engine. This model runs at all times in the Wrangler's computers, and is based mainly on engine oil temperature, engine load and engine runtime. This is why it's important never to reset your Oil Life Indicator, if you have not changed the oil. To do that would introduce a large error in the modeled vs. actual dilution, and increase the probability of engine damage. Wrangler 4xe owners who encounter dilution FORM have commented that their engine oil smells like gasoline. This indicates that the dilution model is correctly identifying and mitigating a potentially damaging situation.
Dilution FORM in the Wrangler 4xe behaves differently, depending on modeled dilution level.
· Step 0: Normal Operation: Below a bottom threshold, vehicle operation is normal.
· Step 1: Moderate fuel dilution: Between the bottom and middle thresholds, silent start allows electric operation during a drive until the first ICE start. After that, you'll see the FORM message and the ICE will continue running until you shut the car off.
· Step 2: More fuel dilution: Between the middle and top thresholds, EV operation is not allowed. The ICE will start when you power up the vehicle and remain running until you shut down, or the bottom threshold is reached, whichever comes first.
· Step 3: More fuel dilution: Above the top threshold, EV operation is not allowed, and the vehicle will instruct you to perform an oil change.
Depending on outside temperature and how the vehicle is being operated, it could climb or descend this ladder. Based on thorough review of feedback from dealership service departments, directly from customers through Jeep Wave, and from social media postings this winter, Jeep believes some Wrangler 4xe customers' engines are rarely warming fully to operating temperature. For this reason, oil dilution is staying between the bottom and middle thresholds (“Step 1”) for extended periods of time in some vehicles operating in cold climates. The user's experience is therefore similar to frequently leaving and re-entering dilution FORM. Some customers may also be experiencing extended periods in “Step 2.” Jeep Engineering and Jeep Wave are not aware of any cases where FORM is acting differently than designed, or where an unrelated hardware issue is exacerbating FORM duration or frequency.
How can I get Electric mode back?
The use case which leads to this level of dilution can vary, but the path to resolution is always the same:
· Start the engine and allow engine oil to reach normal operating temperature. 169°F (76°C) is the minimum, but normal operating temperature is above 194°F (90°C). Elevated speed and load will warm the engine oil most quickly.
· Continue running the engine until FORM is no longer shown in the Message Center of the instrument cluster. Depending on the dilution level, oil temperature and outside temp, this can take from 20 minutes to 2.5 hours.
· In case the above steps are not possible, change the engine oil and reset the oil life indicator.
· Never reset the oil life indicator without changing the engine oil.
It's possible that some use cases lead to a lot of dilution and not enough evaporation to compensate. In this case FORM will return as long as the weather remains cold. We have high confidence that these frustrations will be resolved when the weather becomes warmer.

This is great. Thanks for sharing. We should sticky this.

Vehicle is behaving as expected, but unfortunately, in a manner unacceptable to most users in those situations. YMMV.

 

[Donp]

This is great. Thanks for sharing. We should sticky this.

Vehicle is behaving as expected, but unfortunately, in a manner unacceptable to most users in those situations. YMMV.

Unacceptable is an understatement. If the number of posts that recommend an oil change at very low mileage continue we’ll be spending any savings on fuel mileage on oil changes and then some. So this is a common problem with most turbocharged and direct injection engines? We had a turbo charged Ford Edge for years and never had or heard of this problem. Live and learn.

 

[Sazabi19]

Don't you need to get engine temp up for form? I remember reading in the 4xe forum somewhere that there is a cover for the grill that helps the 4xe get up to proper temp (like 140*ish?) to properly run FORM. Am I remembering several thing and merging them into 1?

 

[GATORB8]

Unacceptable is an understatement. If the number of posts that recommend an oil change at very low mileage continue we’ll be spending any savings on fuel mileage on oil changes and then some. So this is a common problem with most turbocharged and direct injection engines? We had a turbo charged Ford Edge for years and never had or heard of this problem. Live and learn.

I assume you actually turned on the engine and ran it up to temp when you drove the edge. That’s the difference, the fuel burns off into the PCV when it’s run at temp.

Form isn’t an issue, it’s a preemptive solution to keep the oil and fuel in good shape.

The 37s probably help, but we try to do a road trip to go wheeling every couple months. ~7k miles and we’ve never been in FORM.

Also, you don’t need to change the oil filter, just the oil that is loaded with fuel. Castrol edge is $26 bucks for 5 quarts on Amazon, and an oil change is quick and easy.

 

[sentience]

Unacceptable is an understatement. If the number of posts that recommend an oil change at very low mileage continue we’ll be spending any savings on fuel mileage on oil changes and then some. So this is a common problem with most turbocharged and direct injection engines? We had a turbo charged Ford Edge for years and never had or heard of this problem. Live and learn.

It’s pretty insane that Jeep engineers didn’t foresee this issue. Especially being based in Ohio and Detroit.

You placed a 20-25 mile range battery in a vehicle, giving it a 500+ weight penalty (hence worse fuel economy unless traveling short trips) and not realize the typical use case for said vehicle was precisely those same short trips which trigger FORM in cold climates?

What were they thinking? Especially now that the 4xe is going to be placed in Grand Cherokee and likely Renegade and Compass? Asking customers to run their engine for up to 2.5 hours or ‘wait until winter ends’ is asinine.

They are going to have a lot of pissed off customers in salt-belt states and Canada. Really poor execution.

 

[GATORB8]

It’s pretty insane that Jeep engineers didn’t foresee this issue. Especially being based in Ohio and Detroit.

You placed a 20-25 mile range battery in a vehicle, giving it a 500+ weight penalty (hence worse fuel economy unless traveling short trips) and not realize the typical use case for said vehicle was precisely those same short trips which trigger FORM in cold climates?

What were they thinking? Especially now that the 4xe is going to be placed in Grand Cherokee and likely Renegade and Compass?

They are going to have a lot of pissed off customers in salt-belt states and Canada. Really poor execution.

They did foresee the issue, that’s why they made FORM. And, as they mentioned, other PHEV manufacturers do the exact same thing.

The issue is people using this exclusively as a commuter BEV and then whining when the Jeep says you have to run it every once and a while to make sure the engine lasts a long time.

 

[sentience]

They did foresee the issue, that’s why they made FORM. And, as they mentioned, other PHEV manufacturers do the exact same thing.

The issue is people using this exclusively as a commuter BEV and then whining when the Jeep says you have to run it every once and a while to make sure the engine lasts a long time.

Which is an over exaggeration. Just because someone uses their vehicle to commute, doesn’t mean they will only use it to commute. In my case, I was stuck in FORM for two months, during which I changed the oil, and went on trips between Maryland, Pennsylvania, and New York.

FORM finally did clear, but it was only after the weather warmed up. The Jeep engineer mentions this, but that is nowhere in any official Jeep 4xe literature provided to owners.

 

[Sazabi19]

Which is an over exaggeration. Just because someone uses their vehicle to commute, doesn’t mean they will only use it to commute. In my case, I was stuck in FORM for two months, during which I changed the oil, and went on trips between Maryland, Pennsylvania, and New York.

FORM finally did clear, but it was only after the weather warmed up. The Jeep engineer mentions this, but that is nowhere in any official Jeep 4xe literature provided to owners.

Getting the grill cover helps this, it's what it was designed for. It really should be a factory option in the 4xe.

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