odus

So I just picked up my 15 3.5EB truck a couple weeks ago when test driving the idle wasn't super noticeable but it's not something I was looking for. After a week of driving and living with this issue I sat in a friends truck and was like this is a lot rougher than his. So I start my own diagnosis and replace spark plugs they were ****ty looking so no sweat issue was the same. Decided to bring it to ford while I have warranty left as it had a sunroof issue and they figured those issues out quickly. Here we are a week later and a good amount of test performed they have admitted its running rough but have no clue why. no lights on the dash it drives under power fine just noticeable at low speed and idle. Ford has been telling them what to test and change the latest idea was a fuel sensor witch me and the advisor thought was silly and guess what didn't fix it. Hopefully, I can get a smart person at ford to figure this issue out missing my truck and had to fight to get a rental from ford. I am not getting a warm fuzzy feeling with my first ford off the bat wondering if anyone else has had to go above the dealer to get what they need?

bcb97

A couple of things come to mind. 1) Did you gap the spark plugs correctly before installing them? 2) Might need to try a higher octane fuel from a top tier supplier if not already. 3) Dirty air filter? Doubtful but wouldn't hurt to check.

icecoldak

I have come to 99.9% conclusion that FORD service anywhere is freaking clueless--this are the most incompetent run company of workers I have ever seen

landmancrj

Odus
Do you have a CAI?

odus

plugs were gapped to correct gap and no intake only mods are anzo headlights only had the truck couple weeks and its has had 2 tanks of premium run through it and chevron cleaner so fuel should be good. Just sucks they cant figure it out its obviusly spark issue somewhere just strange it drove ok power was there just idle and slow speed you notice it.

tvsjr

Any codes set? Misfire indication?

Persi

I'm glad your sunroof issue was "resolved." What was it?

As far as the rough idle, it's gotta be some type of electronics/sensor issue. If it's not throwing any actual codes (which ANY tech should be able to figure out easily), it may be something with an O2 sensor. Your truck may have been modified by the last owner. Exhaust and tuner mods are very common. Try having a decent mechanic familiar with those type of issues think about the idle problem that way. If the previous owner put the truck "back to stock" before selling it, then there may be something wrong with how they did it. Might be an easy fix.

landmancrj

I would try cleaning the MAP sensor. I know that it doesn't seem like the culprit but you never know. In my experience and slightly dirty sensor will cause that issue. Happened on my Jeep...

I'm no expert, just don't want you to spend unnecessary money at the stealership.

Apples

Also, have a look at the throttle body itself. You may need to spray it clean with an aerosol throttle body cleaner.

odus

I did clean the top two sensors on the intake side there with contact cleaner never looked at the throttle body. I doubt it was modified most the bolts are untouched under the hood that I have looked at. The truck is still under warranty so hoping they could take care of this I get its tough with no codes being throw at them. I know they checked compression I would assume that came back good. Aparently none of the techs at this ford dealer have a clue how to fix it so there just going back and forth with ford corporate and they just keep saying to test this change this. He told me today they might have to fly someone down to look at the truck. I get there trying to work it but I have to go to the dealer to get this guy to answer me its crazy how buys a ford service department is would hate that job. The sunroof was getting stuck they ordered new guides for it. those were ordered a week ago and haven't arrived so must be a common part to mess up if there having issues finding it. Hate the fact I didn't notice this when I test drove it. They told me the dealer I bought it from tried changing coil packs right before I got it so they knew something was not right but just pushed it out anyway. I guess if it gets to a point I just hope someone from corporate will take care of it and not ignore it.