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Ok so all the sudden my 2004 6.0 decides to drop to nothing on the oil pressure gauge on idle but runs perfectly fine. No smoke no hard starts. Oil pressure sending unit? Yes the oil is full.
would you still think sending unit when the pressure goes back up as soon as you apply throttle? I'm having the same problem. figure i have a leak somewhere in the HPO system. same year 2004. yes the oil is full. only does it once the oil warms up to operating temp. i pulled the ICP from the passenger side and it is full of oil, should rule out dummy plug and stand pipe, on that side anyway.
I thought the gauge only read LPO? Are you sure you guys aren't just low on oil? Not sure if the V10 gauge is the same, but it did the exact same thing when it was low on oil (new issue to me, i was 16 at the time) didn't raise pressure until RPMs higher than idle. Make sure it's not something as simple as low oil
am i correct that the 04 late build doesnt have the stc fitting? if the ball is gone replacing the HPOP is the only fix? where does the ball go?will i be able to find it? cheezit i appreciate you responding. THANK YOU VERY MUCH!
It may be on top were the pump sits, it may land in the oil pan. If its in the pan dont worry it will just sit there.
You can pull the pump, tap the plug hole and install a pipe plug.
you were spot on Cheezit, the ball was gone. so the ball isnt a check valve or pressure relief? does the new HPOP still have the ball in them? are the 2004's known for the stc fitting leaking? should i replace it while i'm in there? anything else to replace while i.m tearing into it? dummy plugs, stand pipes,egr cooler is already deleted. oil cooler was replaced.
As far as I know the ball is a casting plug. If you have the cast iron cover there isvan updated one, not cheep though. The supply tube in the early trucks leaked but not near as common as the latter stc style.
If you have wavy rails the dummy plug replacement is a good idea.
could i have injector problems after this. i ran the truck for about 300 miles after noticing the oil gauge issue. i was 300 miles from home ,running interstate about 70 to 72 miles an hour pulling 7,000lb trailer. truck ran fine, sounded normal. made it home, the next night started looking for problem,which was the ball missing from HPOP.