2004 F-350, intermittent low oil pressure warning

Matt Saunoras · January 25, 2013

This truck was towed in with contribution codes, glow plug codes and an underboost stored in memory. Cust states it would not start but eventually they got it running but no oil pressure was reading on the dash. Also it was missing badly so they had it towed in.

I came to me with ECT at 110°F and I didn't want to road test it because #5 was occassionally dropping out and even overfueling at times. Put a few injectors in it, glow plug module, cleaned the turbo and threw in a known good EOP switch because the old one was leaking through the connector. Runs so good I actually forgot about the oil pressure concern.

Drove it 10 miles or so and it's fine until I'm almost back to the dealership. At a stop light my oil pressure gauge drops to nothing, rev the truck up and it pops back up. Get to the shop and while it's running I'm wiggling and pulling the harness every where I can grab. No change according to the asset guy. Shut it off, throw a gauge in the EOT hole and repeat the exact same roadtest, nothing, it's making 25 psi at a hot idle. Back in the shop, pull the regulator and it seems fine. Then I start wondering about the aftermarket oil filter cap.

The filter element is loose from the cap but it appears to be the right one. I've never actually had a problem with an aftermarket filter so I don't know, but I changed the oil anyways and drove it 20 more miles with nothing.

Could the filter cause this? I've changed a lot of switches for the same concern. I'm thinking now my known good switch isn't so good.

mchan68 · January 25, 2013

Change it back to the OEM oil filter and cap before digging further. Once you do, monitor ICP, ICP desired and IPR on your next road test to see how it behaves.

DieselD · January 25, 2013

If its a early build 2004 I have had the ball fall out of the side of the hpop and cause a similar concern. random hard starts, low base oil at idle, but runs great otherwise, etc.

joshbuys · January 25, 2013

If its a early build 2004 I have had the ball fall out of the side of the hpop and cause a similar concern. random hard starts, low base oil at idle, but runs great otherwise, etc.

+1, and occasionally dies at a stop light, but restarts every time.

Matt Saunoras · January 26, 2013

I remember reading a post on the FMC boards about the EOP pigtail holding oil and causing concerns after the EOP sensor was replaced. I'm not sure if it's a load of BS but when I rechecked my sensor this morning it had oil in that weeped back down out of the connector.

Ultimately I replaced the filter, cap, sensor and pigtail and let the truck go. ICP was what I expected during the roadtest. Also the truck was a late 04 with the wavy rail.

Sorry I wasn't clear in my initial post. When the truck lost oil pressure at the stop light it was the gauge on the instrument cluster, not a manual gauge (which I hooked up later and couldn't duplicate a concern)

Matt Saunoras · January 29, 2013

Well the truck is back. Blew the power steering pump shaft seal and made a total mess of the engine bay. It's getting all the lines/cooler too as they are rusted to hell.

No mention of the oil pressure concern, I'll assume for now it's fixed.