I have a 2006 F550 6.0 diesel, I was driving 55 mph and the truck shut off, , I changed the oil pump and it did good for a month and it did it again.It was due to low oil pressure. I have a gut feeling I have a bad sensor somewere. Does any one know what sensor controls the oil shut off.

Thanks

 

Which oil pump did you change originally? Low pressure or high pressure? Why did you change that, was it just a guess?

Have you tried reading any codes? What happens when you try to restart? Are you getting any smoke out of the exhaust?

 

I was told by my mechanic my oil pump went out. The truck had little to no oil pressure. There was no smoke or any weard noises. When I try to start it there is no smoke. The truck just turned its self off. But when its running you would not know there was a issue.

 

When you crank it over, does the oil pressure gauge on the dash come up? You might have to crank it for a bit, like 5-8 seconds to see it come up.

No smoke when cranking means the injectors are not firing. This usually means one of two or three things. FICM is bad... easy to check though, you can find the sticky at the top of the 6.0 page on FICM test procedure. Other than that, it's high pressure oil problem. If the low pressure oil pump is bad it can't supply oil to the high pressure pump either, so it could be one of those. Hard to say without more info. Do you know anyone with a scanner?

 

The gauges shows normal there is no check engine light or any kind of message. They replaced the oil pump on top the engine.
I won't know anything until tomorrow .

 

The oil pump on top is the HPOP for the injectors. If you just think it is a sensor then look on the pass side valve cover, right behind the glow plug module there is a sensor coming right through the valve cover, this is the ICP sensor, just unplug the electrical connector and see if it runs better, if it does then replace it. The ICP sensor tells the computer how much pressure the high pressure oil oil pump is putting out, the other part is the IPR valve which is a regulator to keep the high pressure oil at the proper pressure according to rpm/load/acceleration/ect.
If the ICP doesn't make a difference then pull the IPR valve, it is harder to get to because it sits behind and below the turbo, it is very common for the screenon the IPR to get clogged or broken soon after a HPOP replacement, if the screen is clogged then just clean it off, if it is broken then it must be replaced/ you can buy just the screen, it is alot cheaper then the whole ICP/ if it is broken then check inside the IPR -behind the screen- to make sure there is no debri stuck inside it. The IPR is just an electronic valve/ solenoid/ that opens and closes different amounts to keep the High Pressure Oil at the proper pressures. The truck needs at least 500psi of high pressure oil to start, at idle it might be as high as 1500psi and at full throttle it might go as high as 4000 psi.

 

Good call Bob. We see this a lot actually, when a new HPOP is put in, it always seems to wipe out the IPR with left over debris etc...

 

The truck does smoke when you try to start it. My mechanic told me there is no internal oil leaks and it has 30lbs of oil pressure, He hooked it up his computer and it shows every thing is normal. He changed out the cps and it started and now runs good, But he thinks the cps is not the issue because it looked good. He said he thinks its a faulty sensor in one of the oil pumps .

I had a engine installed with 20,000 miles the truck ran good until I got bad watered down fuel and destroyed 8 injectors, Then I started having trouble.

The first time the truck shut down on me due to no oil pressure and blew one injector I had a new rail installed due to internal oil leak.

2nd time it lost oil pressure I changed out the oil pump I used out of my old engine and it did good for a wile.

3rd time which is now and these tow & repair bills are adding up. So I'm not really sure what the problem is.

 

Sounds like whoever you are bringing the truck to doesn't know how to properly diagnose a 6.0.

When you had water in your fuel and supposedly destroyed all 8 injectors (I find this terribly hard to believe) was the fuel system flushed out?

Typically the CPS and CKP throw false codes when the truck is cranked a lot and not started.

Your mechanic should be able to monitor high pressure oil pressures with ease. If you have 30psi of low pressure oil, what is your high pressure oil readings? It needs 525psi to start. He should be monitoring ICP actual, ICP desired and IPR duty cycle. Without knowing those numbers we are just shooting in the dark here. Has the FICM been tested? It would be nice to know the voltages for that too.