Hello, I have a 2011 Ranger with about 105,000 miles. It has run very well over the years with no real issues. However, it has developed a problem that seems to have stumped the local Ford dealership. I have been experiencing a significant amount of rough engine running. It seems to happen in the 45 to 55 miles per hour range when I am accelerating up a grade. Also, it is intermittent. It will run rough for a short spell, and will do it again a short while later. It doesn't happen when I am going slower or when I am cruising on the highway at a higher speed. The service tech at the Ford house suggested it might be bad fuel, but I kind of doubt it. I have run several tanks of gas since it first started happening, and even put some Heet additive in the tank. Didn't make a difference. The service tech also thought it could be a wheel issue, which I doubt since it is not a consistent issue. He said it's likely not an electrical issue since the "Check Engine" light doesn't come on. Any suggestions on what I might be facing?

 

Welcome to the forum

4.0l V6 or 2.3l 4cyl engine?
Manual or automatic

In general it reads like fuel pump or fuel pressure regulator issue, BOTH are on the fuel pump assembly in gas tank
This could cause a pinging noise as fuel pressure varied but not always because of Knock Sensor, and if its not continuous it won't set Lean codes

You could get a $15-$20 Bluetooth OBD2 reader and watch LIVE DATA on your phone when driving, there is no fuel pressure sensor on Rangers but you could see if voltage was dropping on O2 sensors when this issue occurs, voltage drop means drop in fuel pressure at injectors
Or Fuel Trims(STFT) will go high while its stumbling

There are also other things you can monitor in real time when this loss of power occurs
Could be a Cat converter or muffler has broken up inside, as pieces shift positions it blocks flow so engine stumbles under load but is fine at lower RPMs/Speeds, then piece shift again as pressure builds up and its fine again

There is not much a Dealer, or any mechanic, can do with intermittent issues even if it happens in the shop, which it never does, lol

EDIT
One other thing you can do is to test for AC voltage at the battery with engine running, should be none or very very little AC volts, REV engine a few times while testing
The engine uses two timing sensors, Crank sensor and Cam sensor, both generate their own AC volts as timing signals, if Alternator is leaking AC volts into the electrical system it can interfere with timing signals, and can be intermittent

Google: alternator ripple voltage testing

If its a 4.0l SOHC engine remember to change the 2 timing chain tensioners at 100K miles

 

Did you ever get this figured out? I just bought a 2011 Ranger a few weeks ago and I'm experiencing the same issue.