Hey-I have a sort of odd problem. Wanted some opinions on it before I take the truck into the dealership. I have an '05 F250 6.0L. Bought at the end of April '05, I've got around 6k miles on it now. Did my first oil change at 4700 miles. put in delo 400 filled it up to about 13.5-14 quarts.

Pulled a 3.5-4k lb trailer about 1300 miles. Ran on the freeway at 72 mph mostly flat in tow-haul mode. Everything was fine and dandy, truck ran awesome!

Now on a cold start it idles really poorly just kind outta the blue...smokes a bit on start up, and idle is REALLY quiet, almost like some of the cylinders aren't firing. When I step on the gas it revs ok and the turbo spools up, but the engine itself is really quiet...I poked around under the hood and everything looks good and fine and tight and clean...

takes a bit of driving for it to go away, but even after warmed up it doesn't seem like it's normal self.

Someone suggested maybe I got some bad diesel, but the "water in fuel" light isn't on...

Anysuggestions on what this could be before I take it in to the dealer???

Thanks,
Nick

 

If it winds up not being the fuel then you might want to ask about this:

2005 Trucks, Crank/No Start, Hard Start, Runs Runs Rough at Idle:
Pickups and vans built before 4-15-05 and Excursions built between 1-10 and 4-15-05 may exhibit hard or no start conditions with a low ICP signal, or a rough idle with a high ICP signal. This may be due to a damaged high pressure oil pump and/or IPR valve. The IPR valve should be removed (mounted on HPP cover under the turbo) and inspected for a damaged inlet screen or debris on over half the screen. If either condition is present, the IPR (5C3Z-9C968-CA) and the high pressure oil pump (5C3Z-9A543-AA) should be replaced, along with the oil and oil filter. If neither condition is present, continue with normal diagnosis. If a rough idle is present after replacing the above parts, injector damage may have occured.
TSB 50-12-3.

 

Sounds like a stuck EGR valve to me, take it to the dealer and tell em to fix your espensive truck!
:-)

 

Whistle, let me make sure I am understanding you. Are you saying that your engine is Quiet when cold or is idling rough when cold? Mine is kind of quiet while warming up too. Usually after a minute or two it gets quiet and stays that way at idle for a while, until I step into it. I do seem to remember hearing that when the egr is open, it will get real quiet. I think mine is opening and closing though.

 

do remember that diesels need heat to run properly. thats why its necessary to let them properly warm off before you go ripping out of the parking lot/driveway. i dont think they should run good with substantial power until the whole engine gets up to operating temps. you can start it up when cold, drop it into drive, and mash the pedal and it will sit there and scratch it's head until the engine can create enough heat to run right. thats why it smokes on start up.

 

KW-Thanks-that may be the problem.

olfordsnstone-the engine is running quietly and has no power once I take off. After the engine is warmed up it is louder and runs pretty well. May be a little low on power though.

I thought this was odd because in the past the engine idled loudly when it was cold. Then it would quiet down some once it was warm-I thought this was standard diesel behavior.

One kinda weird twist here-if I turn on the A/C first thing in the morning it idles a bit better and gets a bit louder.

I was wondering if it's possible that a tank of poor quality fuel would do this? I filled up RIGHT before this started happening. The "water in fuel" light has not come on though, so I don't think that's the problem.

strokin_it7.3-I'm not driving the truck like that. I let it warm up for a minute or so like I have since I bought the truck and I drive easy until everything is up to temp. Even then I'm not hard on the truck. It's never been this low on power or idled this poorly in the past.

Is it possible that I'm using the wrong viscosity oil? Should I be using a 10w-40 for start-ups when it's 55 deg F in the morning?

The whole thing just doesn't add up to me-seems like if it's crummy fuel it should run poorly all the time, and it seems like the engine shouldn't be that picky about the oil viscosity...

Any more thoughts here?

thanks for the help!

Nick