Hey everyone, I have a new-to-me 2017 5.0L 4x4 with around 86k miles. I’ve noticed a small vibration that you can only really feel in the floorboard. I was able to feel it when in Drive and stopped for red lights, as well as in Park.

I’ve changed the spark plugs and the vibration is most certainly a lot less than it was before. Most people probably wouldn’t even notice it, again only feel it in the floorboard.

Currently the only time you feel it is at idle around 600 RPM. If you get it up to about 800-850 RPM at idle the vibration goes away. Also the vibration now is only noticed when in Park or Neutral. Vibration goes away when you shift to Reverse or Drive.

I’ve added a bottle of fuel system cleaner, hoping that will do the trick. (All testing was done with AC off).



Seems to be a minor issue, but still worrisome. Any thoughts or input would be greatly appreciated!

 

I can't be of much help to you, but I also have a new-to-me 2015 5.0, and I've noticed a slight vibration at idle when it is in park. I replaced spark plugs, not because of the vibration but because it was overdue at nearly 93,000 mi. The vibration didn't change. I'm not really worried about it because it is just a slight jiggle, and it doesn't do it when I put it in gear. I think it's just because they've got the hot idle programmed too low on these engines. Mine idles right at 500 rpms. Every other car/truck I've ever owned has hot idled at 650-750.

 

If it is so faint that you and only a few others would ever notice it, I don't think it is worrisome.

I replaced plugs in my 2016 around 64,000 or so and it reduced the vibration a lot, but it was hardly noticeable prior to changing plugs.
It was so minimal after I changed the plugs that probably only you and I would notice it.

The point, I don't think it is ever going to be vibration free. Hard to tell from sitting here in my kitchen chair vs the driver seat of your truck just how bad/faint it is.

Worrisome, probably not.

 

Consider running one bottle of Gumout Regaine gas additive a couple tanks to see if the idle smooths out.
My 5 L will do the very sleight idle roughness now and then. The high mileage version of the gas additive seems to clear it up.

 

Would it be worth it to does the fuel properly?
Unless the regain says it treats 36 gallons at a time. Some of the additives want small amounts of fuel.
I'm not trying to argue with Bluegrass, he knows a lot -just wonder though if a bottle in a full tank is the correct dose.

 

I did a bottle with a half tank, same thought.