3.5 EB Rough Idle and shudder

[Byronick87]

quick update guys,
The shudder (for the most part) and rough idle has gone away after about 4000 km
it still shudders here and there when accelerating in normal mode - my guess is just whatever the transmission is doing to try and find the most "eco" gear to slip into.
I will say that after 1000km, I changed my oil.
the local store had a sale on Pennzoil Ultra Platinum Synthetic.
WOW what a difference.
I immediately noticed a smoother acceleration, a bit more response, smoother drives in general and less lurching from when I throw it into drive (not sure if that has anything to do)
this could all be in my mind but I am blown away.
full synthetic from now on even though the manual calls for a blend

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[Dnpbakon]

quick update guys,
The shudder (for the most part) and rough idle has gone away after about 4000 km
it still shudders here and there when accelerating in normal mode - my guess is just whatever the transmission is doing to try and find the most "eco" gear to slip into.
I will say that after 1000km, I changed my oil.
the local store had a sale on Pennzoil Ultra Platinum Synthetic.
WOW what a difference.
I immediately noticed a smoother acceleration, a bit more response, smoother drives in general and less lurching from when I throw it into drive (not sure if that has anything to do)
this could all be in my mind but I am blown away.
full synthetic from now on even though the manual calls for a blend

You changed transmission oil or engine oil? Sorry if I misread

 

[Cincy150]

Which configuration do you have? Powerboost? 2.7?

I have the 3.5 EcoBoost.

 

[Byronick87]

You changed transmission oil or engine oil? Sorry if I misread

No worries. I changed the engine oil

 

[RJL1400]

Hey guys,
Just bought a new 2021 XLT with the 3.5 EB
It was the last 3.5 one on the lot...
When I stepped in for the test drive, I noticed a slight shudder every 5-10 seconds - salesman said it was fine.
didn't trust him - went in and talked to the shop guy; he said it was normal for the first thousand or so miles.
is this true?

Are you touching one of the lane markers. If lane keeping assist is on it will cause a vibration in your hands—which I didn’t know when I test drove one model and that was on.

 

[Carlito's way]

Hey guys,
Just bought a new 2021 XLT with the 3.5 EB
It was the last 3.5 one on the lot...
When I stepped in for the test drive, I noticed a slight shudder every 5-10 seconds - salesman said it was fine.
didn't trust him - went in and talked to the shop guy; he said it was normal for the first thousand or so miles.
is this true?

I have a 2021 with 28k miles on it and already replaced engine in less than one year new. I have about 6k on new engine and since new, prior to engine replacement have experienced rough idle. Good luck and please let me know if your 2022 is better.

 

[Carlito's way]

BTW

Changing to higher octane and even with prime fuel stations no change. Been there done that.

 

[powerboatr]

mine stumbles or idles rough at idle in gear at stoplights, my 2013 and 16 did same thing and was told it has to do with fuel trim and or cylinders shutting off fuel at idle to save fuel. eventually i just ignored it
i found if ac is on max it does not do it, as noticable

if i park and place truck in N it does not do it on normal ac .
maybe its part of transmission programming as well?

 

[Sycotuck]

Hey guys,

I'm dealing with the same thing in my 2022 3.5 eco boost. I had a 2017 3.5 eco boost with a smooth idle for 70k miles.

They had to remove auto start/stop due to chip shortage. I'm wondering if they had to lower the idle or lean it out to claim same MPG without it?

Do you guys have auto start/stop removed from factory?

 

[Sycotuck]

I have a 2021 with 28k miles on it and already replaced engine in less than one year new. I have about 6k on new engine and since new, prior to engine replacement have experienced rough idle. Good luck and please let me know if your 2022 is better.

Clarification. You had the rough idle on your first engine that had to be replaced? What did they say the reason for replacement was? Are you dealing with the same rough idle on the new motor?

 

[Carlito's way]

I had rough idle when I purchased the truck new. New engine burned excessive oil first eight months, multiple trips, loaner vehicles, time spent at dealers, finally getting Ford Motor Company to respond ultimately revealed long block needed replacement. New engine runs fine, no excessive engine oil burns now however, I still have a rough idle. So much, doors rattle uncontrollably at times. Dealer sucks it up by saying its normal. 65K for a rattler.

 

[Spacewhitev8]

I have a 2022 lariat 3.5 and man that idle was rough when sitting at a red light or parked… I have 6,700 miles and I did my first oil change. I did it my self and I used AMS OIL signature full synthetic and so far NO MORE ROUGH IDLE

 

[isthatahemi]

I've owned a few 3.5's, they all occasionally shake at idle. Raising the idle 100 rpm fixes it

 

[isthatahemi]

I have a 2022 lariat 3.5 and man that idle was rough when sitting at a red light or parked… I have 6,700 miles and I did my first oil change. I did it my self and I used AMS OIL signature full synthetic and so far NO MORE ROUGH IDLE

FFS, snake oil is not the difference maker.

 

[Quattshot]

I contribute it to the truck putting you into 10th gear basically within 3 seconds after you start accelerating from a stop. It’s totally ridiculous and I hate the feeling. Are there any software upgrades to fix this? Thx

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