Hello all!

I have a 2012 F250, 6.2L, Crew Cab, FX4 with a little over 77,000 miles on it. I bought it used from a Ford dealership last summer. Prior to now, I've only had one issue with it and that was squirrel/rodent induced. Something chewed through the wiring harness right before the connection to the #7 cylinder. There was enough left over wire to solder it back together and put heat shrink around each wire.

It ran fine up until last weekend. The wife and I went to a store, she was driving and parked like a total jerk right in the front area of the parking lot. When we got back in the truck, she started it up and it was just running rough with hardly any power. My first thought was someone dumped something into the gas due to her amazing parking, but there were no smells or residue of anything near the gas cap when we got home only a couple miles away.

When I got home I ran my code scanner and found 300, 301, 305, 307, and 308. I dumped a bottle of ISO-Heet in it, let it sit for a bit then cranked her up and ran it for a few miles to the gas station and filled up...about 25/26 gallons, I don't remember...I was a little above 1/4 tank when this all started. No change in performance and the codes were all still the same. I pulled the MAF, it looked clean, but I wiped it down anyways and threw it back in. No change. I then changed all the plugs. This took care of 301 and 305 but 300, 307, and 308 were still coming up. I then picked up two new coil packs for cylinders 7 and 8, threw them on and still no change.

I sat with it running on a flat surface for a little while reving the engine randomly for about 15 minutes, during this I noticed a fast tapping noise at about 3400 RPM, it went away quickly with no changes in the gauges on the dash. I cant really tell where it's coming from, but kinda sounds like its under the middle of the truck.

While sitting there I ran the codes again, and now its back to 300, 301, 307, and 308. I'm now at a loss of what to even look at...

I've also checked the voltage coming off the harness at the connector to the coil packs...just under 11 volts. I've searched all over for what that voltage is supposed to be, but have failed miserably in my searches.

Any help or advice would be greatly appreciated! Thank you!!

 

I have no idea what your codes mean, but did you do a compression check? I have a 2012 6.2 and I broke an intake valve spring. Of course, it was a dead miss on the cylinder with the broken spring, but it had to have some affect on other cylinders with this compression being forced back into the plenum/intake. I have no idea if this is your issue, just throwing it out there.

 

you replaced all 16 plugs.

did you reset the computer..

what is the voltage at the battery with engine running.

 

The codes are misfires with the last number indicating the cylinder.

I did not reset the computer...didn't even think of that, I'll head to Youtube university and see if I can learn how to real quick (I'm assuming just disconnect the battery for a bit right?) I'm surely no mechanic and fear I'm treading into areas I shouldn't be. Ha ha. I can do the basics and a very little more, oil, plugs, tires...have done a couple clutches...

According to the cheap bluetooth code reader I have, the control module voltage while running stays pretty steady between 13.4 and 13.6 while running. MAF stays between 7 and 9 unless I rev it, then it shoots up. Timing advance is all over the place, same with vacuum

 

Oh, I also just had my reader on it for a bit again and it's back to 1, 5, 7, and 8 misfiring...always a combo of these cylinders. 2, 3, 4, and 6 have never shown up in the codes.

 

see if local auto parts store loan out a fuel pressure gauge setup..
many do.

measure fuel pump pressure..

as one bank is mis-firing.
also I find the cylinder report number is not always correct..

 

Reset the computer and still no changes. I'll swing into a couple auto parts stores tomorrow for a fuel pressure gauge.

 

I have a 2011 f350 6.2l as well and I am having a cylinder 8 misfire code and a repetitive ticking noise at higher rpm's. Can you tell me what you ended up doing?

 

My issue was catastrophic. Cylinder 8 had zero pressure and I had to do an engine swap.

 

Pull the valve cover and look for a broken valve spring. It's a fairly simple fix if your mechanically inclined. There are videos on YouTube as well.

 

Ya I'm going to pull the valve cover as soon as I get back in a couple hrs. I'm hoping that's all it is.

 

Are broken valves springs common with this engine?

 

There are no common problems with this motor that I'm aware of. Like winning the lotto to have issues with a 6.2 IMO.

 

Yeah, the 6.2 is a rock solid engine. Very very few issues. Check out the engine section.

 

Not common but it has happened. Like mentioned, the 6.2 is a rock solid engine with no "common" problems.