Low oil pressure

[Mc2027]

Hey I have a 2013 Lincoln mkt 3.5L eco boost with 250k miles and I’m have a problem with my oil pressure it keep saying a low oil pressure when I came to a stop or when idling and it could turn off right away. So I connect a manual pressure gauge and it was within spec at 1500 rpm’s it was reading 50psi and the minimum is 30psi that’s what the book says. So I replaced the sensor and it did not come up for about a month but last week it started to do that same thing. I have already changed the oil and filter and there is no strange noises coming from engine. Is the main bearings going out or is it the oil pump if so why did the light stop coming on for a month the day the changed out the sensor? Should I replace the sensor again? I bought the sensor from napa for about 40$ could it just be the sensor again?

 

[FordFlintrock]

What is the oil pressure at idle (hot engine) when the warning comes on is the question. What is the repair history of the engine?

 

[ProjectSHO89]

Could be the switch, a connection issue, wiring problem, or a PCM issue besides an actual oil pressure issue.

Keep in mind that the "sensor" is simply a pressure switch, it does not provide an actual reading of the pressure. The switch is designed so that it is supposed to be closed at 4-6 psi and opens at lower pressures. Due to this design, any intermittent open circuit between the switch and the PCM's OPP input will register in the system as 'low pressure".

Your best course of action would be to tee in that manual pressure gauge semi-permanently so you can have a real pressure reading and verify that the problem is the switch circuit vs and actual low pressure condition.

 

[peterk9]

Hey I have a 2013 Lincoln mkt 3.5L eco boost with 250k miles and I’m have a problem with my oil pressure it keep saying a low oil pressure when I came to a stop or when idling and it could turn off right away. So I connect a manual pressure gauge and it was within spec at 1500 rpm’s it was reading 50psi and the minimum is 30psi that’s what the book says. So I replaced the sensor and it did not come up for about a month but last week it started to do that same thing. I have already changed the oil and filter and there is no strange noises coming from engine. Is the main bearings going out or is it the oil pump if so why did the light stop coming on for a month the day the changed out the sensor? Should I replace the sensor again? I bought the sensor from napa for about 40$ could it just be the sensor again?

Welcome to the Forum.
Have you tried posting in the Lincoln MKT forum? Lincoln MKT Forum to see if others may have had the same issue? This forum is for the 5th gen Explorer.

Peter

 

[ProjectSHO89]

The oil pressure monitoring circuit in the MKT is the same as the Explorer.

 

[Andy14sport]

Could be the switch, a connection issue, wiring problem, or a PCM issue besides an actual oil pressure issue.

Keep in mind that the "sensor" is simply a pressure switch, it does not provide an actual reading of the pressure. The switch is designed so that it is supposed to be closed at 4-6 psi and opens at lower pressures. Due to this design, any intermittent open circuit between the switch and the PCM's OPP input will register in the system as 'low pressure".

Your best course of action would be to tee in that manual pressure gauge semi-permanently so you can have a real pressure reading and verify that the problem is the switch circuit vs and actual low pressure condition.

Thanks for posting this information. Do you mind if I ask where you found the 4-6 psi spec? I can't find that anywhere in my manual and I'm currently trying to diagnose a low pressure warning in my 2014 sport. I have 20-22 psi at hot idle and 60-80 at higher rpm. I have a new switch showing up tomorrow. Your post gives me hope that I don't have excessive bearing clearance, or a problem with the Melling HV oil pump I installed last year when I did a complete timing set.