My 2016 6.7 let me down yesterday while driving through Kansas in 99 degree heat. I'd just returned to the freeway after a short 10 minute stop during which I'd left the truck idling to keep the dog cool. The Low Fuel Warning flashed on the panel and it went into low power mode.

I made it to a station and cycled the ignition 15 times to try to bleed air out of the system. Ran for a few more blocks and then slowed to a few miles an hour. Subsequent cycling made it obvious that the fuel system wasn't pumping diesel - I could hear both pumps whining.

I Uber'd the family to a hotel to get them out of the heat and waited for 2 1/2 hours for Ford to sent a tow truck. I have a long-bed crew so the local truck wasn't long enough.

While waiting at the (closed) dealership, the ambient temperature dropped to 95 and the fuel system straightened out - no whine and it ran fine.

I expect that the diagnosis tomorrow will be NPF. What tests should I ask the dealership to run to ensure this doesn't happen in western Kansas when I'm headed back to Colorado? Is there anything that will exacerbate the problem other than temperature?

Should I have them keep the truck for some time and ask for a loaner?

 

Filters clean and tight?

here's a similar thread that hopefully will help you

http://www.thedieselstop.com/forums/f149/low-fuel-pressure-reduced-engine-power-after-fuel-filter-change-562097/#/topics/562097

 

Thanks, seville, I'd seen that thread but my filters were replaced at the dealer 11,000 miles back.

 

Well, it's going to be a long day. Dealership changed the fuel filters and took it for a test drive. The three low fuel pressure error codes came back. Service manager called to say they're going to drop the fuel tank and look for obstructions and bad fuel. When I told him I add PM22A to every tank he "guaranteed" me that I dropped a seal from the bottle in the tank and that's the problem with the mechanic on speakerphone. I hate it when someone doing the troubleshooting pre-determines the problem. That's so amateur. I hope they don't prove themselves right artificially. Makes it hard to trust them now.

I treat preparation for adding the additive as an operation and haven't dropped any in the tank. No one else uses my truck. Of course, per my assertion of predetermination I can't decide that it didn't happen in spite of my precautions.

I was out of additive on the previous fill-up and didn't add any.

Anyone else have to fight this with a dealer?

 

They sure enough found a cardboard circle the size of an FM22A bottle in the fuel inlet. I bought a bottle and the counter and pried out the lid gasket. It's a different material than the one they found in the tank.

I'll be back on the road soon.

 

This is all on me. The dealer found a second cardboard gasket in the tank before bolting the tank back in.

I've been afraid of ensuring that none of the foil seal got my tank but I should have been watching the gasket. I found an old bottle of FM22A in the garage and it had the same material gasket. I discovered that, unlike a new bottle the cardboard gasket will fall right out. And the older style bottle has the same gasket.

Although I can only blame myself for being carless, it seems that the gasket should adhere to the cap more readily since you can't use a whole bottle at a time. It comes out easily by tapping the lid on your palm.

The root cause is the diesel industry in most states for selling only fuel that has too low a cetane rating. Or Ford for designing an engine that doesn't run on the diesel available.

But that doesn't excuse my incompetence.

 

mistakes happen; that's how we learn. At least you found the answer.

Many years ago I had my first small diesel tractor. Started running real rough once. Finally figured out i had accudently put gas in instead of diesel. Dumb move, but it taught me to label my fuel cans "diesel" or "gas" in large black markers.

it's the littlest things that cause the biggest problems