“Low oil pressure” dash light…
 

2014 F150 5.0 with 230k on the clock.
Oil changed regularly with 5W-20 per owners manual.
Oil level is correct.
No leaks.

Last week, my low oil pressure light came on after coming to a stop (after driving about 2 hours) and the engine shut down. I put in neutral and started it back up. Drove it the quarter mile home with no problems.

I drove it for a couple of days replaced the oil pressure sensor Friday, with a Motocraft sensor, as they’re known to go bad. I replaced it several years ago as well.

Today, after driving 2.5 hours, I pulled into a gas station, came to a stop, and the low oil pressure light came on again. The engine stopped. Put in neutral and started it back up.

Now I’m worried.

What are the chances of having two bad pressure sensors?

Any advice on where to start looking?

I’m going to change the oil tomorrow with a Motorcraft filter. There’s a Purolator on now

Just get behind the cluster and tie it to your alternator light.... ;)

No seriously, the only peace you'll get is putting a mechanical gauge on it. It is running hotter?

rjp

I agree with Randy, get a gauge on it and see the actual pressure.

Not sure you have the same problem but will share this story:

I went through something similar with my Dodge 1500 with the 5.7. I found I had a bunch of carbon buildup in the pan which would eventually clog the oil pickup strainer. Shutting the motor off allowed it to fall back into the pan. I confirmed this with a USB boroscope in the pan through the drain hole - was able to see carbon chunks everywhere.

They did something goofy in the design of those motors - the PCV valve is integrated right into the intake manifold and close to the EGR intake port, so you get a bunch of carbon somehow makes its way back into the oil.

Dropping the pan on my truck is a major PITA - Ran some motor flush, drained it, put a tube up the pan drain hole and pumped in a some kerosene. I was able to flush out a handful of carbon buildup. I've run a motor flush every oil change since without any repeat of the issue.

Good advice above for direct reading oil pressure gouge.

Found this on the www:
2012 F150 5.0L Problem Fixed. I changed the oil pressure sensor about 6 months ago. Stopped for a little bit then started back. Started having issues with idle so first i changed my oil pressure sensor again since it had oil on it from a rear main seal leak. Here is link to show the easiest way of doing it. https://youtu.be/uta45V4e2Mo Then had my oil changed. Brought it home and replaced the spark plugs and took the throttle body off. The throttle body I think was the cause of everything. It had a lot of build up so I cleaned it with throttle body cleaner. Do not use carburetor cleaner. I heard this could ruin the coating in the throttle body. Put it back together and the idle is perfect and I haven't lost oil pressure. I believe the issue with the oil pressure was from the idle dropping too low.

Guess it is possible that something is causing idle speed to drop too low and then low oil pressure switch and message shuts it down?
Does selecting "Neutral" when stopping, stop the shutdowns ?
Maybe time to consider 5w30 oil ?
Cheers

I had a leak at the oil pan and replaced the oil pan with a new gasket a year or two ago and all was clean, including the oil pick up. You reminded me to replace the PCV valve.

I’ll clean the throttle body and am thinking of heavier weight oil.

at 230k miles it's prolly burning some, or a bunch of oil... You seeing any CELs?

I went to Motorcraft only on my Ford vehicles after having an odd oil pressure problem in a 3.5 V6. Something about a pressure relief in the off brand, don't recall specifics. I'd definitely get a gauge on it. Do you have a live data OBDII scanner? I like "old school" gauge but a live data scanner is a quick clean. I think Forscan offers oil pressure reading

From doing a little reading, there's debate as to whether your truck would have an actual pressure value associated with the pressure sensor.

At a minimum run 10w40 oil .

No CEL or burning oil. The 230k is a lot of highway miles.

I have a couple of OBD scanners I’ll have to look at. Need to see if any codes are present. I just received my Forscan OBD connector.

So, right now, I’m looking at:
Clean the throttle body
Replace the PCV valve
Heavier weight oil
Scan for codes
Mechanically measure oil pressure. Will need gauge etc.

It not running hot, but the weather it is in the 90’s.

^^^
Good luck! There are a few threads that say "yep it can be done" and then users who say "nuh uh". We never see that kinda stuff here on the Pelican forums, do we? It's apparently found in the PID settings so if the oil pressure setting appears when connected, you should be good to go.


Nothing wrong with cleaning the TB but I'd wait till you've changed the filter and PCV. Me, I'd leave the oil at 5w20 but that's just how I roll. The gauge you can get from Harbor Freight.

At the risk of starting an "oil war", I recommend switching to a 5W40 oil, especially at that mileage. Could be a cheap fix. Isn't the 5W20 and lower vis. oils related to better fuel mileage (CAFE averages)?

Maybe it IS just crappy idle speed causing oil pressure to fall below the sensor threshold- that's a good theory for an otherwise non-abused truck.

I'd be waiting for it to overheat and get that funky smell that happens, clacking too- VVT gets awfully mad under low oil pressure.

The latest Modulars are really good engines, I'd be surprised if it crapped out for no good reason.

rjp

I replaced the PCV today and I’m about to change the oil now. I know I’m using the shotgun approach, so if it stops, I won’t really know what did it. But driving 800 miles or so a week, I need the truck running.

When I did the transmission fluid and filter the other day, I noticed a front sway bar and link was broken, so I’m going to replace that as well.

THat was my thinking too. Keep the low end (cold flow) number the same, but bump up the top (hot) number which enhances viscosity at the hot end.

He's in S.C. there is no issue running 10w40 . I am next door in north Georgia . It is HOT and humid . The last thing you want is thermal runaway .