Engine idling

[MCHammer]

I’m new to the F-150 and the 3.5L EcoBoost. I love the acceleration, but I notice that when I’m idling the RPMs generally sit at 700 (0.7k). Then it will occasionally pulse up or down by 100 RPMs and I feel a little vibration/rattle. Can anyone tell me if this normal and to be expected?

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[currybob]

I’m new to the F-150 and the 3.5L EcoBoost. I love the acceleration, but I notice that when I’m idling the RPMs generally sit at 700 (0.7k). Then it will occasionally pulse up or down by 100 RPMs and I feel a little vibration/rattle. Can anyone tell me if this normal and to be expected?

Mine does not do that nor did my 2018 EcoBoost

 

[Hershal]

I have noticed a rough idle similar to your description. I have not driven mine much because I have a work truck for another week. I planned to take it in if it persisted.

 

[Gen14]

Mine does it also but not all the time.

 

[MCHammer]

I only 250 miles on it, so wasn’t certain if it would resolve as the engine breaks in. I’ll definitely bring it in if it persists, but I wanted to understand if this was typical.

 

[KBKEITH]

My former ‘18 3.5EB did not idle funny like that.

 

[diesel97]

I’m new to the F-150 and the 3.5L EcoBoost. I love the acceleration, but I notice that when I’m idling the RPMs generally sit at 700 (0.7k). Then it will occasionally pulse up or down by 100 RPMs and I feel a little vibration/rattle. Can anyone tell me if this normal and to be expected?

Maybe its the fan clutch or air conditioner

 

[Sancheznan25]

I’m new to the F-150 and the 3.5L EcoBoost. I love the acceleration, but I notice that when I’m idling the RPMs generally sit at 700 (0.7k). Then it will occasionally pulse up or down by 100 RPMs and I feel a little vibration/rattle. Can anyone tell me if this normal and to be expected?

I also have a 3.5 and I to have experienced the same rattle and vibration. First time owning a truck in general so not sure if this is normal or not

 

[75032Limited]

My 2011 used to do that (1st year of the Ecoboost and 1st gen) Did it since new, and did it until the day that I sold it. I remember that it was more pronounced until I fixed a vacuum leak. (1/2" hose going into the intake post filter.) Just a loose hose. Most likely not your case.....

That was on the first gens - DI only so it could have been related to that.

Could it be the engine changing from DI to SMPFI? (Direct Injection vs. the Multiport Fuel injection)

 

[sonofzell]

Maybe its the fan clutch or air conditioner

That was my first thought as well. I've not noticed this behavior on my current or previous EB's, but both were/are 2.7's.

 

[Twilighthan]

Same 3.5EB Issues even after 7k miles. Rough idle.

 

[MCHammer]

Same 3.5EB Issues even after 7k miles. Rough idle.

Have you done anything about it or brought it in under warranty? I’m only at 800 miles, so wasn’t sure if it would be premature for me.

 

[Twilighthan]

Have you done anything about it or brought it in under warranty? I’m only at 800 miles, so wasn’t sure if it would be premature for me.

No. I haven’t had time and can’t lose my truck for them to figure it out eventually. It is weird, but since i haven’t owned this type of engine before, I’ll let it be and see what happens.

 

[Gen14]

FYI my 2018 3.5L did this sometimes also. Sometimes it idles at 5-600RPM (rough idle) or 700 RPM (smooth). A/C and/or Fan on or off doesn't change anything. The only thing that made it go away was a tune on my 2018.

 

[Grussell59]

I have the 3.5 and it always has a rough idle with or without the ac on. I have 8,000 miles on it now. Runs good, but the idle is noticeable.

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