2021 2.7 Ecoboost Rough Idle

[txmedic9110]

I just bought a new 2021 F-150 with a 2.7 Ecoboost. When I test drove the truck there was a rough idle with only 48 miles. The salesman stated that I probably needed to be driven to get rid of the rough idle. 1000 miles later and the rough idle is still there. I took it to my local Ford dealership and they checked it out and stated that it is a normal "characteristic" of EcoBoost 2.7 engines. Is this true?

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[Knickell]

Can you be more specific as to the rough idle? Is it more of a sound from the engine, or vibration feeling?

I have a 3.5 EcoBoost that constantly makes what I would call a faint whining noise, but I’m convinced it’s normal from my research.

 

[txmedic9110]

It's a vibration feeling as if it was misfiring.

 

[BigShan808]

Off a cold start and/or initial startup mine idles rough. But as it warms up the idle diminishes and it smooths out. It happens intermittently when driving and coming to a complete stop at intersections. It's not consistent. Happens pretty frequently if I run with regular 87 octane. I do shell out the extra $$$ and fill up with 89 (non-ethanol) and the rough idling happens mostly on cold starts. Any other 2.7 owners out there that can attest to this?

 

[dmac]

A friends STX 2.7L has it on cold start high idle only. Did some digging and it looks like it may be intentional timing retardation by Ford to expedite the warmup/lower emissions. Makes sense since it runs perfectly smooth after rpms go down to normal idle.

Check out the last post on this page

https://www.f150ecoboost.net/threads/rough-idle-on-cold-start.1530/page-3

Another claimed ford tech also claims it to be normal in that thread.

Update - it needed to have the idle relearn procedure done. See my posts on this forum.

 

[Dan Duryea]

I just bought a new 2021 F-150 with a 2.7 Ecoboost. When I test drove the truck there was a rough idle with only 48 miles. The salesman stated that I probably needed to be driven to get rid of the rough idle. 1000 miles later and the rough idle is still there. I took it to my local Ford dealership and they checked it out and stated that it is a normal "characteristic" of EcoBoost 2.7 engines. Is this true?

I experience the same rough idle on 2021 3.5L Powerboost as well.

 

[BigShan808]

Experience the same on my 2.7EB on almost every startup but idle smooths out when the engine is warmed up.

 

[Ritchie457]

I just bought a new 2021 F-150 with a 2.7 Ecoboost. When I test drove the truck there was a rough idle with only 48 miles. The salesman stated that I probably needed to be driven to get rid of the rough idle. 1000 miles later and the rough idle is still there. I took it to my local Ford dealership and they checked it out and stated that it is a normal "characteristic" of EcoBoost 2.7 engines. Is this true?

My 2.7L runs and idles with no rough spots at all. Very pleased with my engine choice.

 

[dmac]

Another datapoint, my brother noticed the idle only after he disconnected the battery to reset Sync 4. Apparently that wipes learned engine parameters. This is the idle relearn process that will speed up the learning of parameters:

https://onlinecarrepairmanuals.com/ford-idle-relearn-procedure

I will perform today and let you all know if it helps.

 

[dmac]

So I did the procedure and its idling great now, even on cold start.

 

[ragazzi_07]

mine does this as well. i notice it happens more when the car is in "normal" drive mode.

if i switch to eco it smooths out and not noticeable.

but it shouldn't be happening in the first place.

 

[wres2021]

So I did the procedure and its idling great now, even on cold start.

I've struggled with a really rough idle since new, specifically when the AC is running and temps are above 80 but it's always been somewhat noticeable. Very frustrating. Saw this post around the idle re-learn and tried it this morning and after following the steps the rough idle is completely gone even with max AC and 95 degree temps outside. Appreciate this link!

 

[kp texan]

I've noticed this on my 2.7 as well since new - it's mostly noticeable while sitting at a stoplight with my foot on the brake and the A/C running, and it's just a slight stumbling vibration that I can feel and also see in the water in my water bottle. Going to do the idle relearn and see how it does after that. Thanks!

 

[Doggy-Dog]

My 2.7 has a smooth idle. Never ever noticed it acting like it was missing.

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