My dad has a 2012 F-150 with the V6 ecoboost engine that may be experiencing a possible misfire. However, this one seems a litter different than from what we have been reading online about the misfire issue. This particular issue we can reproduce multiple times in a row in either wet or dry conditions.

What happens, is under heavy acceleration, once we hit 3500 to 4500 RPM's it's starts to hesitate. However, it clears up above 4500 RPM's and the engine runs smooth again. The check engine light does flash for a few seconds then goes out.

Does this sound like the "typical" misfire issue many have talked about or does it sound like something different? He normally ones the 87 octane E10 gas and has around 40K miles on the engine. His intercooler does not have any of the plastic guards on it. So far it has not ever gone into the dreaded limp mode.

Any insight into what this could be would be appreciated! I'm sure he'll be taking it in to the dealer to see what the deal is, but we are curious if this is the misfire issue or something different.

 

40k is right about where the spark plug gap issue pops up. I'd replace the plugs.

 

Could also be a bad Coil on Plug, but if it were mine I would scan for codes and then change the plugs using the proper Motorcraft part number gapped to .030 to.032". I drilled a 1/16" hole at the bottom of my intercooler near the outlet end and that stopped the water buildup issue. Also don't be driving it with the cel flashing as the unburned fuel you are dumping into the exhaust will melt the catalyst substrate in short order requiring a new cat to fix it.

 

That's interesting. Does that issue have to do with the gap widening? I'm not as familiar with that particular side of the equation.

 

I had read where some have done that. I don't know a whole lot about how the tubocharged system works, but wouldn't that small hole technically be a "leak" in a closed system? Perhaps it's small enough to let the water trickle out but still allow the turbos to maintain boost where it wouldn't make a difference?

 

The vast majority of the time the intercooler (CAC) is under positive pressure so there is not great opportunity to suck in debris under vacuum. Also it is just a 1/16" hole. really not big enough to cause any consequential loss of boost. Several thousand miles and not 1 issue since drilling the hole. No difference in the way it drives or the fuel mileage. An added benefit is I didn't empty my wallet to the catch can snake oil salesmen.

 

Some of them seemed to widen, but there were many plugs installed at the factory with varying gaps. The gaps were inconsistent and out of spec. Plug change on the 3.5 Eco is very easy to do.

 

Turbo motors are just rough on plugs. They run higher cylinder pressures and they just don't last. Swap in the latest version of Motorcraft plugs and most misfire issues are resolved. You can get the plugs for about $35 and it only takes a little bit of time to change them.

 

Any time after 30K miles these engines need new plugs. Turbocharged engines as a whole are hard on plugs. They will never last 100K miles without misfires. SP534's with a maximum gap of .030--$24 dollars a set from O'Reilly. Plugs first then check coils.

I have ran my CAC with a 1/16th hole drilled in it for 30k miles. I can put a screw in it to temporarily plug it. I can tell no difference in the #of boost either way, the hole is just too small. At most a .5% drop.

 

Has your Dad made any plans to head into his dealership yet, semperfif150? Once he gets this diagnosed, I'll be able to check out some ways to help. Be sure to keep us posted!

Crystal

 

I would throw a new set of plus on it long before playing Russian Roulette with a stealership. Who knows what you'll get there, some techs are solid but there are plenty who are incapable of changing the oil without stripping the drain plug. The problem is you will be paying $100/hr or so either way.

I changed out my plugs again yesterday morning. I took my time and was still done in 45 minutes. All you need is a 5/8 spark plug socket on a 3/8" ratchet with a few extensions and a 8mm socket to pull the coils off. I checked a few plugs and the gaps were in the .038-.040 range. When I installed them all were gapped to no more than .033". I knew they were getting old because I too had a high RPM misfire under a load.

The problem is with a large gap the spark will be blown out or weakened so that it doesn't properly ignite the fuel air mixture. This is more pronounced in a turbo motor because of the higher cylinder pressures compared to a N/A motor.

 

Ive always heard around 40k is a good time to change the plugs on the Eb.. I'm at 41k running custom tunes and so far i haven't had any misfire's and still get good fuel economy.. Im going to try to get em to 50k before replacing but if i get a misfire it will be done alot quicker.

 

The wider the gap, the quicker they will erode as well. I ran mine at .025 for 24K and had only a .027 gap when I changed them out. This time I gapped them to .028 hoping to get just a smidge more gas mileage. Not that I was getting bad mileage anyway, I just made an 1800 mile trip to Colorado most of it at 75mph+ carrying about 1500 lbs of cargo and got 18.6 mpg for the whole trip. So far no spark blowout at this gap.

 

Well i jinxed myself




Made it to 41750 before i felt a little bit of a misfire when on it hard.


Checked the gap on the new plugs and they are dead on .030, going to tackle the job in the morning.

Anyone who has done this, do you have to disconnect the coils or can you leave em plugged in? I hate screwing with the damn red clips

 

There's not much slack on the wire bundles. I would be afraid of breaking a wire if you don't disconnect the coils. Plus you will need to disconnect the HPFP connector to pull the #6 coil and plug.

Here's the easy way to get them off.
-Pull the locking tab back
-Push the connection into the socket
-Push down on the locking clip
-Hold the clip down and pull the connector off

If you push the connector in it will take the pressure off the locking tab and make it a whole lot easier to unlock.