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03 f450 6.o no start when warm

todd

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union center ny
any ideas it is kicking a lot of asses since it is in the local meat waggon and they really need it. we have had it for about a month now and cant figure it out,replased the oil tube and have tried every computer diagnostic known to man to no avail. any ideas?:mad2:
 
Check your oil level / change your oil. the 7.3 and 6.0 Powerstrokes use an HEUI(Hydraulic Electronic Unit Injection) system that uses engine oil to feed a Common Rail under the valve covers. that common rail is what actually "fires" he injectors. Low or crappy oil can cause the HPOP (high Pressure oil pump) not to operate.

If that doesn't solve the issue then Injector O rings. Cold oil is more viscous and wont bleed past the ICP. hotter oil(then add 3K psi behind it) will bleed the oil past the O rings and cause it not to fire warm.
 
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There is a sending unit on the heui that reads oil pressure. Did the 6.0 have cam sensor problems like the 7.3? Might check.
 
There is a sending unit on the heui that reads oil pressure. Did the 6.0 have cam sensor problems like the 7.3? Might check.

Could be an issue, but thats not really a common problem on a cold start /warm no start issue. One of those failing is usually irratic rail pressure / poor operation and or no start at all as the PCM/IDM can't read rail pressure. Still a good idea though :thumbsup:

No. Ford solved the Cam sensor issue sometime in 2000 and all the 7.3's(and engines to follow) didn't suffer from that issue after that. Don't remember the EXACT years when the Powerstrokes had that problem, but he isn't one of them.

To the original poster - whats the trucks mileage? Miles since last oil change? Temperatures your operating in? And are there any codes?
 
How about the plug for the injector harness into the valve covers? I know I did the quarter (25 cent) fix on my 7.3 that I have and have never had a problem since. The CAT in my service truck would shut down from a failing oil sender. Took me awhile to find it cause I thought it was the pump itself.
 
it was

under the intake is a bad o ring replaced the whole fuel rail and injector cups, cahinged the oil and it solved the problem, thanks big blue chevy you were right on target
 
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99% of the time with a 6.0, if you have a no start when warm issue, it is because there is a leak someplace in the high pressure oil system.

The high pressure oil pump is located in the valley of the engine under the turbo. 2005 and 2006 engines have a stc (snap to connect) fitting between the pump and the oil rails that is prone to leaking. There is a repair kit from Ford that adds a bracket across this fitting to secure the connection.

I am not sure of the best way to locate where the leak is on the newer 6.0s. However, on my 03, there was a plug in the oil rail that you could remove. Then you could use a rubber tipped air gun pressed against the plug hole in the oil rail to pressurize the system. However, I know the design of the oil rails changed a bit between different years of the 6.0, so I don't know if the same can be done on the newer oil rails.

O-rings in the stc fitting and in the oil rail to injector connections are also possible failure points. I would bet that one of these o-rings is what failed in the example stated above.

There is a minimum pressure that is required for the injectors to fire. When oil warms, it thins out, and so the amount of oil flowing through a leak increases. That's the reason for the no start when warm condition.
 
99% of the time with a 6.0, if you have a no start when warm issue, it is because there is a leak someplace in the high pressure oil system.

The high pressure oil pump is located in the valley of the engine under the turbo. 2005 and 2006 engines have a stc (snap to connect) fitting between the pump and the oil rails that is prone to leaking. There is a repair kit from Ford that adds a bracket across this fitting to secure the connection.

I am not sure of the best way to locate where the leak is on the newer 6.0s. However, on my 03, there was a plug in the oil rail that you could remove. Then you could use a rubber tipped air gun pressed against the plug hole in the oil rail to pressurize the system. However, I know the design of the oil rails changed a bit between different years of the 6.0, so I don't know if the same can be done on the newer oil rails.

O-rings in the stc fitting and in the oil rail to injector connections are also possible failure points. I would bet that one of these o-rings is what failed in the example stated above.

There is a minimum pressure that is required for the injectors to fire. When oil warms, it thins out, and so the amount of oil flowing through a leak increases. That's the reason for the no start when warm condition.


You hit the nail right on the head my friend:thumbsup:
 
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