I have a 2004 F-350 6.0, 120K on it. Disconnected EGR and pulled butterfly in intake, Blue fuel spring. Rerouted ccv. I installed a new injector a year ago. Stock everything.

Past couple months it has developed a miss. It runs rough throughout the entire powerband. When I changed the oil a couple weeks ago it got far worse. Mileage has been horrible. No smoke. Scangauge has no codes popping up. FICM has 48V. I replaced fuel filters last winter.

I'm looking for help troubleshooting this. Should I have it scanned by a shop? Maybe the SCII is not picking up something? I know at least two glow plugs need to be replaced. Starts hard when chilly out. MUST be plugged in less than 30deg. Not sure that would have anything to do with it...

Any help on this would be much appreciated!

 

The scan gauge is not a good code reader, I would take it to your local AutoZone and have it scanned for DTC's. Are you using OEM/Racor oil and fuel filters and OEM oil filter cap? Also what weight of oil are you running?

 

Oil is rotella 15w40. Stock style cap, motorcraft oil filter. Not sure about the fuel filters.

I'll get it scanned for sure.

 

First thing I would do is switch to full synthetic 5W-40 diesel rated engine oil, your injectors will thank you. Here is the link to a video that shows the difference in aftermarket and OEM oil and fuel filters and shows a non OEM oil filter cap,

 

Next oil change go to wally world or TSC and get some 5w-40 T-6 sythetic, find the sponsor for the oil and fuel filters and order and get them cheaper than going to Ford ( Racor or Motorcraft ). Might want to try some Hot shot secret to see if makes a differance and also pull EGR Valve and see if it is dirty. If the trucks isn't getting used often the turbo could be sticking from the center section rusting and bonding to unisom ring , mine seized so bad it sheared the pin in the rack and pinn assy. that controls the variable vanes Piston was moving but not the vanes or actuation shaft.

 

could be a Few things

changing oil to synthetic should help

It could be Dirty inject spool valves

leaky inject orings You will have diesel fuel in the Oil if this condition is present Iv had this Issue and one symptom is Runs Bad Cold but Good when warm because the Inject oring leaks when cold and seals when warm


Use the ScanGaugeII and check everything possible first

FICM
HPO
CAC System

 

besides everything the guys have mentioned, i'd also be open-minded to the possibility tat the fuel pump might be an issue too. just my 2 cents.

 

Had it scanned. No codes.

I cant imagine oil being an issue since I've ran rotella since day one.

 

Its not the brand that's bad its the weight 5w 40 synthetic rottella has been good to my Injects, also try the revX on the OIL side of Injects to clean them up. and get Blades some Values from the gauge

 

Ok. Had it scanned again. Pretty sure the scan prior was not done correctly. Codes that popped were

Glowplugs for cyl 2 and 8. Explains hard starts and poor running until warmed up.

MAF sensor. Reading low but says still within parameters?

EGR- But that's because I unplugged it.

So truck still runs rough intermittently. About 50% of the the time. Especially at idle. I think I was wrong about the mileage. It's still ok. 14mpg stop and go driving, pulling 5K trailer half the time so should be good there.

I'll do the switch to synthetic but skeptical on oil being the source of this specific problem.

Blade35- FICM is ok at 48volt. HPO is high pressure oil pump I assume? And I have no idea what the CAC system is. Any input would be appreciated. Thanks. I better crack open that tech folder...

Thanks everyone for the help so far!

 

CAC would be all of the piping to/from the turbo, intercooler etc. Check all of the boots for any pinholes or cracks. This is a fairly common problem and is worsened if they are soaked in oil. Check to make sure the pipe to the intake elbow isnt broken if its plastic.

 

Mustang mike is correct on the CAC boots pin hole ,splits, loose band and CAC housing its self is plastic and will crack ,you will need to look at=
1. Map= and hose connection to Intake the little port off the nipple will clog.( don't spray MAP senser just clean Intake).
2. EGR Valve=,( clean with carb cleaner ,but not the Electrical side wrap a rag around this section and use a plumbers flux brush to clean).the discs move up and down clean where they seat. better to put new o-rings and disc in if not new.
3. EBP and tube to the Manifold=( make sure the manifold hole is clear)soak with PD-40 then wrench sometimes the nuts will be rusted on)use some weed eater line to clear the tube to manifold and make sure the senser hole is OPEN DONT SPRAY.
4. MAF= ONLY use Maf Cleaner on this and IAT1 if there .
5. IAT2=Will be Behind the upper fuel bowl and will be Sooted up use the carb cleaner and brush when clean theres a orange ball with 2 hard wires exsposed, this will help in the air temp and fuel delivery.

and ware your safety that stuff burns like,
May need to Change to the 5w 40 and run a Rev X treatment on the Oil side of the Injectors.
Do you run a fuel treatment? ( diesel klean ,howes etc).

 

FICM is good at 48v Don't let it drop below 45v.

 

Exact DTC would help


MAF is Needed for Boost Cac in ealy truck

Hows the Air Filter??

Clean it as 04BADFORD said with that cleaner

Need a Gauge to check MAF Values

You can take a DVM and check the MAF make shure its got 12volts and V-Ref and Ground


Plug the EGR Back in