Hey guys I need some help, I started getting the “low oil pressure” warning on the dash Tuesday, it would only happen when I was coming to a stop, and as soon as I would accelerate again it would disappear. I just had my oil changed at the Ford dealership two weeks prior so I thought that maybe they didn’t add enough oil or something but oil levels were fine so i started researching and came across a lot of 5.0 trucks having problems with the oil pressure sensor going bad or having oil in the connector. So yesterday I bought new motor craft oil & filter, and a new sensor and changed everything out and drove it yesterday evening and had no issues, but today I’m driving around down and it starts again. Any ideas on what to try next? I cleaned out the connector twice while I was swapping the sensor with carb cleaner and hit it with some air to make sure it was dry and no debris was still in there. Any help would be appreciated.

 

Bumping this thread... same thing has happened to me. Low Oil Pressure warning upon stopping, back to normal as I resume acceleration. Would also go off if I put the truck in N and up the RPM to ~1k. Happened every other day for a week or so but has not occurred again.

To OP- I researched this when it started happening and was lead down the path of "Oil Sending Unit Failure"... stopped happening after it sat for 5 days while out of town so I have not followed up.

 

First of all, the oil pressure needs to be checked.

 

Ok so update, I hooked up a mechanical gauge today and after warming the engine, stopped, in gear, I’m showing 16psi.

 

Low idle in gear, oil warmed up... that pressure sounds good. I recall reading somewhere from Ford on a 302 engine that you should have 10psi per 1000 rpm.

 

When I initially replaced the sensor, I used a non-oem part, maybe the psi threshold is different? I’m going to leave the mech gauge on until Saturday and check it throughout the week, and replace with OEM. Just a side note for ppl with future issues like this, I installed a 90* brass elbow coming out of the engine block, and screwed in a male air hose fitting, and a female fitting on the hose for the mechanical gauge, made for easy install and I will install the female fitting on the new sensor when I’m installing that.

 

Back in the day I had direct gauges installed in my 1976 Monty Carlo. One of the three was oil pressure. Tubing was routed through the firewall. I love being able to monitor what the actual pressures was at varying rpms. The other two gauges were coolant temp and battery.

You just may have a switch with a higher threshold. Get an OEM.

 

For as cheap as the OEM sensor is, I would have definitely picked that over aftermarket. Different Ford dealers have different prices, so be sure to call around until you find out which dealer is the "cheapest" one in town. The OEM sensor is about $7 or $8. But good job cleaning the connector out, a lot of people miss that step.