6.0 Cold Driveability

[jpmutt79]

What is the most common problem found on the 6.0s when there is a cold runability issue? We're seeing more and more with the same problems. They start very rough and missfire like crazy when cold or have been setting a while, and after they warm up they seem to run better. I suspect injector problems but would like some input. There seems to be an endless list of possibilities.

 

[Bad Moose]

Change engine oil to synthetic or synthetic blend. Injectors don't like thick oil, That's why when engine warms up miss goes away. Or plug truck's block heater in.

 

[SINNER]

spool valves. Like said synthetic is much better but even good dino oil should run flawlessly at start up. They will progressively get worse until it misses when warm. I have freed sticking spool valves with a quart of diesel in the oil, run for 5 minutes than do 2 oil changes with a 5 minute run between. Idle only. The HPOP reservoir holds about a quart of oil you can not drain out. Thats why i did 2 changes to get all the fuel out. Not the best solution but it got another 20k out of a dying work trucks injectors.

 

[jpmutt79]

Yeah I think you're right about the spool valves. I have two right now that are doing the same thing. One is an early 04 the other is a late 04. The early 04 I just found the ICP sensor was biased. Replaced it and found it blown apart. We'll see what happens I guess. The late 04 wont even start unless it's plugged in. It's setting a P0671-cyl.1 glow plug circuit code but it definitely has other issues. It misses when it's warm too. I just put a new FICM on this one because it died while driving and then would not restart. FICM got it running but it sure runs like $hit.

 

[joshgilvin34]

alot of times a cold problem is a programming issue. ford comes out with updates every so often that the computer needs and it corrects certain issues like that. also the ficm could be losing m power voltage. the ficm needs at least 47 volts at all time if it starts losing then you will def get those exact concerns you are having.

 

[mdub707]

My buddies 05 is/was having exact issues, only problems when cold. Its in the shop now getting headgaskets and EGR cooler...