Hey guys I'm new here and have a problem my 6.0 has 72k on it never had a problem and i do regular maintenance myself the past few days its been hit or miss on starting it its just recently been getting really cold here... figured it was some bad fuel i got the night before from a small convenience store but there's still a problem and its beeen warmer today too, I've got some ideas on what could be the problem but unsure... ie oil pump, injectors, ficm, glow plugs, or a relay mayb as simple as filters please help with any info it would be appreciated

 

is it cranking long, slow? What exactly is it doing?

 

Like Bigblock said...Need some more info. When you say cold out, how cold is cold? What oil are you using and when is the last time you changed your fuel filters? Are you using any additives, injector cleaner?

 

Hey sorry guys for lack of info like i said new to this yea its crankin got plenty of juice and cold is in the teens but it was warmer today still havin problem drained the fuel from line and filters used some lucas additive changed the oil bout 3k miles ago filters were changed then too used motorcraft 15-40 oil thinkin of switchin to schaffers 15-40 synthetic like i said one morning didnt start at 19 degrees the next it did at 11 degrees when it starts it runs fine except one time a few weeks ago when i was driving it seemed to kinda stall a bit like it was choked or not gettin fuel but it started fine then got any thoughts on that? injectors, FICM, mayb glow plugs, or relay of some sort crossed my mind

 

You say it has been hit or miss the last couple of days. When you do get it started does it idle rough for awhile and then smooth out when warmed up. Does it smoke at all when you get it started and what cooler of smoke.

 

yea hit or miss as in its like it has a mind of its own starts when it wasts haha... anyway no doesn't idle rough smooth as can be and when it starts after sittin all night get some white smoke as expected the other day it seemed to have a bit of a blue tint MAYB my eye sight sucks

 

I'm not sure where to begin as far as hunting this problem down. I had a friend who had to have his injectors replaced in his 6.0 at 50k not sure why tho....

 

Under the hood on the drivers side near the firewall is a black box with labels on top for relays and fuses. This is where if memory serves me correctly is where the ficm power relay is and fuses for the ficm and for the glow plugs. Open it up and make sure all connections look good no corrosion or loose connections. You could also move the wiring harness around to see if there is a spot that has worn through someplace.

 

oh man thanks i didnt kno where those were at, been wonderin I'll go check its a start... do you kno where the fuel pump relay is on those just for reference.

 

Well no luck there all connections at first glance seem to be good no corrosion a bit of dust around outside, wiped it off. All connections looked good tho when i removed the relays... what bout an easy way to test the relays? or do you have any other suggestions, couldn't really see the harness that good its dark but didn't notice any frays

 

You should probably think about switching to 10-30 for the winter. When it's cold the 6.0 runs a lot better on a lighter oil. Check your 6.0 manual about operating temperature ranges. If you've been running the 15-40 in winter for the whole time you've owned the truck, you've probably got some clogged injectors. I've been switching to 10-30 each winter on the advice of my diesel mechanic and only use the 15-40 during the summer. I've had no injector or hard starting problems and I'll bet it gets colder here than where you are. Do you know if your getting any codes. If it's injectors, you'll get a code. I'm not sure what number off the top of my head.

 

I dont think i'm gettin any codes, i'm not gettin a check engine... and yea it doesn't get that cold here it usually stays in the 20's on cold nights in winter we just had a spell where in got into the low teens and i thought of switchin to a lighter oil just wasn't sure if it was a good idea... will the injectors still click right if they're clogged? i was unsure haven't checked that yet but am goin to today oh and if my oil pump was messed up would my pressure gauge still be showin good pressure when i was crankin it?

 

Conger is right there is a TSB by ford that recommends the followng.
SAE 15W-40 is the preferred oil above 30 degrees, but it is acceptable for use down to 10 degrees, and is recommended for towing down to this temperature.
SAE 10W-30 and 5W-40 is acceptable for use below 30 degrees, and 0W-30 is acceptalble below zero.
The reason per TSB, some trucks with the 6.0 may exhibit hard starting, rough running and lack of power in cold temperatures particularly on a cold start. This may be due to the oil being to thick for the operationg conditions.

There is another TSB 04-17-13
In cases of a hard or no start caused by an inoperative, or intermittent glow plug system, inspect the module connectors for damange, loose or displaced terminals, spread termnals or corrosion. Threre is a harness connector service kit available to repair 2003 and 2004 engines. At the top of this forum there is a tech folder thread. Look in it for the 6.0L bible for locations of these components. Also the cam shaft sensor and crankshaft sensor have to feed a signal back to the PCM in order for the engine to start you could look at those connectors as well.

 

try plugin in the block heater at night and see if that helps.

 

yea it has been plugged no help one day i ran it for bout an hour ran perfect like a champ then i shut it off went inside my parents house to have dinner when i came back out it wouldn't start still warm and everythin hadn't been turned off long... if someone has an idea on the problem that i mentioned having a few weeks ago bout the truck seeming to stall or choke up in first gear for a moment, would that be related to this like i said it seemed to not be gettin fuel or like it was choked... just bogged REAL bad... what could that be... problem wit the filter mayb.... clogged line, injector?