I bought a 2004 Excursion 2WD about a month ago. 3 owners. It was a southern truck, so not rust. Right at 210,000 miles. Got a CarFax and a stack of records from owner #2 (last owner put about 40,000 miles on it). Checked most of the boxes off from what I could tell and didn't see any major things that were deal breakers. Drove it back home 5 hours.

I've only driven it a little since winters are yucky here in Illinois, and I want to fluid film it when the weather gets better. I did drive it on a trip two hours away. Coming off the interstate, the engine seemed to stumble coasting at idle on the off ramp and then shut off as I coasted into a gas station. The engine fired right back up, no hesitation, and I had no issues for the rest of the trip. Got home and changed fuel filters since I didn't know when they had last been changed. Also drained the fuel water separator on the fuel pump.

Fast forward to today - same thing happened at a stop light going around town. Truck went from a smooth idle to off instantly. Put transmission pack in park and it started right back up. I hooked my scan tool up - no DTC codes stored. Ran the Key On Engine On test - aside from some codes for the cruise control switch, nothing odd popped up.

The engine doesn't like to start below 30 degrees - previous owner had recently done oil change with Rotella T6 15W-40. I usually run Rotella T6 5W-40 in my diesels because it is colder where I live. My 2003 6.0 F250 never has an issue starting even when temperatures are in the teens without plugging the heater in. Was planning on switching to that along with running a quart of Archoil 9100. Maybe I should try doing that sooner than later.

Could the fuel pump be going out? Oil pressure issue? ICP or IPR? I have a copy of Forscan on my laptop, but I don't know where I would start looking at data since it is such a random thing.

Thank you for reading!

 

So NO stored codes that FORScan can find?

Does this issue seem to have ANY relationship to a low fuel tank level? You really do need a fuel pressure gauge (all 6.0L owners do)!

Using 15W40 oil at temperatures below 30 * F is not wise, because spool valve operation has to be virtually perfect and you need some sort of engine heating.

 

Thanks for the reply. I haven't hooked up ForScan yet - just used my craftsman scan tool to look at codes. I'll try to find my USB dongle this weekend and hopefully check it out.

When the truck shut down the first time, the tank was registering about half full. I wondered if the fuel gauge could be off, so I filled it up immediately. It took about 17 gallons, so the gauge was fairly close. Second time it shut off, tank was reading between 3/4 and full. Drove home 20 miles with no further issues, so I believe low fuel level is not an issue at this point.

 

My guess would be that, with that quick a dropout and restart, a wire in the harness is shorting to ground.

My truck used to do that with its original harness when it was not that old. Once the harness was replaced, many years later, it never happened again. It was particularly hard right-hand turns, which I learned to avoid, but if it happened at speed, I could put the truck in neutral, restart, and go back into drive and continue on.

With so many harness issues early on, these are not getting better with age.

 

This sounds like it could definitely be the case. Would no codes likely be tripped if it was a short?

A few years ago, I replaced the harness on my 2003 F250 with the 6.0 I've had it for the last 100,000 miles (bought it with 80,000 in 2012). It has gone through two FICMs and two alternators, otherwise no big issues with it. I replaced the harness due to a no start issue (wouldn't fire off at all). After replacing the harness, still wouldn't start. Replaced the FICM and all was good, though the harness did show some signs of wear, so I didn't regret taking care of it.

 

I don't ever remember having a code. But that was 15 years ago.

 

Some shorts will throw a code and others won't (unfortunately). Always worth checking w/ a good scan tool (ie FORScan and not a tuner)

 

Changed oil over today to Rotella T6 5W-40 with Archoil 9100 additive. Will see if that helps with cold starting tomorrow morning. Still haven't checked for codes with FORScan. I'll report back if I find anything.

 

Just to give a (hopefully) final update - checked the battery cables under the hood (which I should have done immediately). Had a ground that was not tight. Haven't been able to replicate the problem since tightening.

Thanks for the feedback and suggestions!

 

Appreciate posting the conclusion. Just for others that might have similar issues (in the interest of possibly finding a root cause quickly), did you ever check for codes with FORScan?

 

So I did finally find my adapter, and I have several stored codes in the system:
P0404, P0407, P0488 - looks like EGR related?

Several codes for glow plugs:
P0673, P0674, P0675, P0678 - I suppose this would be contributing to the hard starts in cold weather.

Couple of codes related to the overhead computer (It wasn't working when I bought the truck, but I sent it off and had it repaired, so hopefully those codes don't come back).

At this point, is this enough to go on with the EGR codes to diagnose, or should I pull some live data with the truck running?

Thanks!