3.6 with off idle jerking stumbling resolved

[Petey]

A while back I started noticing that @ about 6k miles the car had torque spikes under 2k rpms (it had jerking during acceleration).now at 15k it was just way more pronounced and started to act like clutch chatter ... which I could have sworn it was but .. could u believe the air filter was the culprit. changed it... and got my bottom end torque back..(makes little sense) did nothing else ..was going to change the plugs because I was absolutely sure that was the issue..
Looking at the old filter one would say it is still usable and I can't imagine that it was already going bad @ around 4 or 5K miles...my driving is 99.99 percent city.
Are there any sensors before the Throttle body that could cause something like this?

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[roaniecowpony]

Mass Air Flow sensor.

 

[roaniecowpony]

You stated the rig has 15k on it, but the filter had 4-5k on it. What brand was the air filter?

To put this question in perspective, I have ~23k on my 2018 3.6 JLUR. A small percentage has been dirt roads and trails. Maybe a couple hundred miles. My original filter is probably due or overdue for a change, but it isn't causing any obvious problems.

 

[Petey]

You stated the rig has 15k on it, but the filter had 4-5k on it. What brand was the air filter?

To put this question in perspective, I have ~23k on my 2018 3.6 JLUR. A small percentage has been dirt roads and trails. Maybe a couple hundred miles. My original filter is probably due or overdue for a change, but it isn't causing any obvious problems.

Filter (original , with the chrysler mark on it)and rig being both the same milage ..around 15 k miles .. started feeling the engine jerking @ around 4-5k miles .. the filter looks perfectly serviceable yet ..this. So there might be more to this but the filter change is all I did ...I touched nothing more. This is the first time in my life a change of filter yielded the same results as replacing failing plugs . I cant believe it myself. What could possibly cause such a strange outcome

 

[Petey]

Mass Air Flow sensor.

maybe there is an issue with it , but as it stands , now nothing I could tell after the filter change I'll add to this and say I bought a cheapo one from amazon about 20 something bucks ..most likely a Fram brand

 

[mwilk012]

Mass Air Flow sensor.

You sure?

 

[roaniecowpony]

You sure?

No. What's the electrical connector go to?

 

[zakaron]

No. What's the electrical connector go to?

That would be the air intake temperature sensor. This engine does not use a mass airflow sensor; it is speed density based with a MAP sensor instead.

 

[zakaron]

I would be curious if you hung onto that old filter that if you put it back in, will the engine go back its same behavoir? Unless the filter was somehow defective from the start, it does not make much sense that only a filter change would have such an impact, unless that filter was severely clogged... but you indicated it was not. And I have no idea how a filter would be defective to begin with.

 

[Petey]

I would be curious if you hung onto that old filter that if you put it back in, will the engine go back its same behavoir? Unless the filter was somehow defective from the start, it does not make much sense that only a filter change would have such an impact, unless that filter was severely clogged... but you indicated it was not. And I have no idea how a filter would be defective to begin with.

the same are my thoughts and the reason I posted this .. I still have it but even though its just 5 screws to change it back I know what the result will be if I do. I'm willing to take a pic but it still looks like slightly used filter ....nothing that one could visually go on is wrong. There is something truly strange about it and am wondering if it might not be a symptom of another problem

 

[roaniecowpony]

Something you might try...
Disconnect that intake temperature sensor and see if that causes the same symptoms.

 

[Petey]

I would be curious if you hung onto that old filter that if you put it back in, will the engine go back its same behavoir? Unless the filter was somehow defective from the start, it does not make much sense that only a filter change would have such an impact, unless that filter was severely clogged... but you indicated it was not. And I have no idea how a filter would be defective to begin with.

Also, with in mind of the last part on my reply, I found my engine very sensitive to anything less then than 90 octane rating. There would audible pinging from of idle to 1900 rpm under load.

 

[Petey]

Something you might try...
Disconnect that intake temperature sensor and see if that causes the same symptoms.

Will do

 

[mwilk012]

I am starting to think that all of the people with pinging or other issues are having problems with the newly designed EGR on the upgraded pentastar engine.

 

[Petey]

Something you might try...
Disconnect that intake temperature sensor and see if that causes the same symptoms.

The results: the engine light (orange)lit up and slightly rougher idle but none of the previous problems before the filter change

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