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To be 100 percent honest, no software update will help with oil consumption. The computer has no control over that. I’m sure it is just a way for Chrysler to “ make you happy” and think the problem is solved.
Obviously a computer update will not affect the fit of the rings, plug a leak, or seal a gasket. However, the update affects the valve timing that was previously creating excessive vacuum and sucking oil into places where it shouldn't have been going.
 

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Discussion Starter · #22 ·
Why can't the dealer re-do the test and this time bring it in at the exact mileage


they want you to?
Why can't the dealer re-do the test and this time bring it in at the exact mileage


they want you to?
Obviously a computer update will not affect the fit of the rings, plug a leak, or seal a gasket. However, the update affects the valve timing that was previously creating excessive vacuum and sucking oil into places where it shouldn't have been going.
I agree - valve timing could be a factor and worth adjusting before replacing a motor which might not solve the problem!
 

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I agree - valve timing could be a factor and worth adjusting before replacing a motor which might not solve the problem!
Ok, have there been any other motors that have this problem. If you are sucking oil thru your exhaust valves, would make me assume the piston rings are the problem, how else would oil get into the cylinder and and sucked out of the valves? Which brings me to my next point, if what you are saying is true, why hasn’t every car Jeep makes with this engine needed, valve timing adjustment. I have yet to hear that my car needs an update
 

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Ok, have there been any other motors that have this problem. If you are sucking oil thru your exhaust valves, would make me assume the piston rings are the problem, how else would oil get into the cylinder and and sucked out of the valves? Which brings me to my next point, if what you are saying is true, why hasn’t every car Jeep makes with this engine needed, valve timing adjustment. I have yet to hear that my car needs an update
The valve timing adjustment is via a software update, and it does apply to other FCA vehicles with the 2.4L Tigershark engine. I have read on this and other forums that the update successfully reduced oil consumption for many owners.

There are several threads about it here, here are a few:

Recall issued 1/29/2021 powertrain software update (oil...

Recall on certain 2018 Jeep Compass vehicles with a 2.4L...

Oil consumption recall issued
 

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The valve timing adjustment is via a software update, and it does apply to other FCA vehicles with the 2.4L Tigershark engine. I have read on this and other forums that the update successfully reduced oil consumption for many owners.

There are several threads about it here, here are a few:

Recall issued 1/29/2021 powertrain software update (oil...

Recall on certain 2018 Jeep Compass vehicles with a 2.4L...

Oil consumption recall issued
My question is has there been any other engines other than the 2.4 that have have this issue or is this the first time and engine design has had the problem. Is there any documentation on the update and how the problem is occurring, and how changing timing takes care of this. I don’t mean to challenge what you are saying, but it’s an answer to a problem with no explanation
 

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My question is has there been any other engines other than the 2.4 that have have this issue or is this the first time and engine design has had the problem. Is there any documentation on the update and how the problem is occurring, and how changing timing takes care of this. I don’t mean to challenge what you are saying, but it’s an answer to a problem with no explanation
The closest thing to an official explaination I have seen is a post on the Allpar forum, by an FCA representative (the equivalent to @JeepCares on this forum) about how the software update addresses the issue:

OfficialMopar said:
Hello, the oil consumption concerns are caused from vacuum being created in the cylinders during deceleration. Software changes the events, internal to engine, that lead to creation of vacuum.

If you need any help setting up an appointment, feel free to let us know.
Kaitlin
Mopar Cares
Jeep Cherokee Oil Consumption TSB/Recall

The 2.4L engines in these Compasses use Multiair2 technology, so there is no direct mechanical connection between the cam and the intake valves, the intake valves are opened and closed via an electro-hydraulic system, so unlike more conventional engines the valve time can be changed at will via software.

 
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Discussion Starter · #27 ·
Ok, have there been any other motors that have this problem. If you are sucking oil thru your exhaust valves, would make me assume the piston rings are the problem, how else would oil get into the cylinder and and sucked out of the valves? Which brings me to my next point, if what you are saying is true, why hasn’t every car Jeep makes with this engine needed, valve timing adjustment. I have yet to hear that my car needs an update
I believe oil exiting the exhaust valves is not the basic problem. The problem is (in several Tigershark 2.4L engines) the intake valves are programmed to close too much for too long in the intake and possibly compression cycles which creates too much vacuum in the cylinders in those cycles. That excess intake vacuum in the cylinder combustion chambers then pulls the oil past the piston rings and into the combustion chambers which will ultimately cause the oil to then be burned in the combustion chambers or pulled out of the combustion chambers on the exhaust stroke. The fix whereby the intake valve timing and/or opening/closing duration is adjusted so the intake valves stay open a little longer and/or at a different time in the appropriate cycle to lessen the vacuum generated in the cylinders at the appropriate time in the cycle(s) so that the oil stays in the cylinders and is not pulled out past the rings and subsequently burned in the combustion chamber or possibly oxidized in the catalytic converter if the oil makes it to the cat, again depending on the valve timing and opening. Simple enough if the valve timing adjustment, by itself, works, which several people have said this procedure did cure their excessive oil consumption issue.
 

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I believe oil exiting the exhaust valves is not the basic problem. The problem is (in several Tigershark 2.4L engines) the intake valves are programmed to close too much for too long in the intake and possibly compression cycles which creates too much vacuum in the cylinders in those cycles. That excess intake vacuum in the cylinder combustion chambers then pulls the oil past the piston rings and into the combustion chambers which will ultimately cause the oil to then be burned in the combustion chambers or pulled out of the combustion chambers on the exhaust stroke. The fix whereby the intake valve timing and/or opening/closing duration is adjusted so the intake valves stay open a little longer and/or at a different time in the appropriate cycle to lessen the vacuum generated in the cylinders at the appropriate time in the cycle(s) so that the oil stays in the cylinders and is not pulled out past the rings and subsequently burned in the combustion chamber or possibly oxidized in the catalytic converter if the oil makes it to the cat, again depending on the valve timing and opening. Simple enough if the valve timing adjustment, by itself, works, which several people have said this procedure did cure their excessive oil consumption issue.
Thank you very much, that is what I was looking for. You are the first person to be able to explain it. Everyone say just do the update and it’s fixed sounds shady. Thank you for shedding light on the situation.
 

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Discussion Starter · #29 ·
Thank you very much, that is what I was looking for. You are the first person to be able to explain it. Everyone say just do the update and it’s fixed sounds shady. Thank you for shedding light on the situation.
It was a long-winded explanation but hopefully helps people understand the problem!
 

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Thank you very much, that is what I was looking for. You are the first person to be able to explain it. Everyone say just do the update and it’s fixed sounds shady. Thank you for shedding light on the situation.
Most of us have already discussed the deceleration cylinder vacuum stuff to death in other threads previously, that's why nobody (initially) re-typed the long explanation here in this thread (until you asked).
 

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I don't know if the problem is the same, but several other manufacturers have had oil consumption problems. Just do a web search for "excessive oil consumption" followed by a brand and your bound to find some hits. e.g. Honda Engines Oil Consumption (use) Issues They all follow the party line "its normal." According to that link, Honda says 1000 miles/qt is OK. At least Jeep did something about it. Maybe others will follow.
 

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Most of us have already discussed the deceleration cylinder vacuum stuff to death in other threads previously, that's why nobody (initially) re-typed the long explanation here in this thread (until you asked).
Makes sense, but wouldn’t you think adjusting valve time to fix the oil problem, will in turn cause a loss of power.
 

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Makes sense, but wouldn’t you think adjusting valve time to fix the oil problem, will in turn cause a loss of power.
No, not I this case. According to the info we've read from jeep reps, this timing change is only for deceleration and possibly idle conditions, not accelerating or cruising.

One of the members here got the update done and he reported that his car no longer sounded like a diesel at idle. When I get the update done I will be listening closely for that. Still waiting on HPTuners to write definition files for our PCM so I can see what the update actually, really changes.
 
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