Drove a few hundred miles this weekend, no problems. Truck ran fine.

Started it this morning, gauge said no oil pressure. Light was on. Shut it off, started it again. Same. Then the gauge jumped to normal, light off. I let it idle for 20 seconds, then took off. Gauge dropped back down suddenly, light came on. Within 5 seconds, it popped back up and never went back down. I drove away slowly, listening... no sounds, no hesitation, no anything. No puddle of oil in the driveway.

Stopped at a gas station to check oil. Was about a quart low, which isn't unexpected for me with a small leak at the valve cover gasket. It usually loses around a quart every 3-4 weeks.

So my question is... bad sensor, or big problem? Its an '01 Screw, 5.4L 215k miles. I'm contemplating leaving work to go to my garage, but its an hour away and I figure if I am going to take this thing down the freeway at 70 mph for an hour, it better not lose oil pressure or else I'll be stuck with a really, really bad case of the Mondays.

 

Clean the sending unit and it's connector. It's just one wire and they can break inside the insulation causing intermittent problems. Check continuity and power while moving wire at the same time.

It could be more serious than that, but check that first.

 

Yeah, I'm thinking sending unit too! or a loose wire at the unit

 

Thing is, I'm stuck at work. Not to mention, I have no idea where such a pressure sensor and associated wiring might be.

My usual repair guy wants me to make the drive... I am just afraid that I'm going to flat out die on the freeway before I can make it.

 

I don't blame yuh. If it's the pump or pick up screen it could blow right after start. If it's the sender/bad connection then you should be alright. It's a chance you take driving it.

You could start it with the hood open and listen for clatter. You'll hear clatter first with no oil pressure. Up to you.

If it's not the sender, then the fix is going to be expensive regardless. Could be cheaper replacing the engine with a low mileage used one.

To work on the harness and wire loom to the sender, you pull the drivers side wheel and plastic inner fender. From there you'll see the sender attached to the block, toward the front. It's at the end of the last wire in the harness, -furthest down the block, - just 1 wire, white connector.

 

I don't think its the pump or pickup screen, as I not only started the truck 3 times then, but I drove to work, let the engine cool, and tried starting it once more. No smoke, nothing.

Define "clatter." It's had a tick for several months, I just assumed its the engine getting old, maybe the valves sticking, etc. Never gave it much other thought. I haven't heard any different nosies today, but I spent most of my time in the cab.

When I started it a few minutes ago, had the door opening (listening) but was in the cab. The gauge jumped right up to normal. I guess in my head, it makes sense that it would be the sensor failing. I don't know how to test it, though, and it only tripped up that one time this morning.

 

I'd replace the oil pressure sender on general principle - it's only about 10 bucks.

 

When the oil stops circulating you'll hear clatter under the valve covers, before it blows. No, not a tic, completely different.

If you lose oil pressure completely, I'd say you have about a 1/2 mile before you blow a piston/wp,cr or whatnot. -It doesn't take to long after losing all of it.

From your description, it's most likely just the sender/connection. She does have some miles on her tho. If the correct oil, filters were always used in the past and if it has been changed properly, the 5four should last well over 300,000 miles. Something to keep in mind, - it's very important the correct products are used when maintenanced.

 

She'll heat up and go into fail safe mode, IF it's still running at all.

I'm not positive, but like I said, it sounds like a sender problem.

PM me with your email and I'll send instructions for your model, IF you plan to do this yourself. Specify 2wd/4wd.

 

Here's a couple Normal starts and gauge reaction -

1998 5.4L w/279,000 miles, -Factory sender/gauge -

https://picasaweb.google.com/1002891...90121627213570

2001 5.4L w/58,000 miles, Factory sender/gauge -

https://picasaweb.google.com/1002891...84705673453298

 

I am going to agree with you on the principle that you obviously have some experience with this. Not to mention, i've driven about 35 miles since it happened this morning with no problems. Gauge hasn't dipped at all.

Thanks That looks quite familiar...

I've decided I'm going to hang out here (in Detroit) for the night. If it gives me any more problems, I'm calling a toe and getting it checked out by someone who knows what they're doing.

I may PM you later to get the details.

 

Good Luck.

 

That's real confidence inspiring jbrew... :P

 

He coulda said "Bad Luck!" How'd that work out for ya?

 

Bad sender. Very common on 01s. There was a TSB about it.