Low Oil Pressure/Oil Pump Failure Issues

[prncssmelissa]

2013 Edge 3.5L 155K

 

back in January, we replaced the head gaskets and the water pump due to bad water pump. no issues after that until September. 
 

I was driving down the road, the low oil pressure warning came up on the dash and it cut the engine. Haven’t seen it since. It turns over and tries to start, but doesn’t start. Battery is less than 6 months old and it cranks, it just won’t actually start. 
 

called both of my mechanics - they agreed that it was likely a sensor (oil pressure sensor). Mechanic 1 came and changed it out but it didn’t resolve the issue. Mechanic 1 is unable to continue working on it due to injury to his back, so Mechanic 2 took over. Mechanic 2 has replaced the oil pump and did an oil change. Still won’t start. Changed the crankshaft sensor(s) to no avail. Same symptoms - it cranks and tries, but doesn’t start. 
 

what else could be the issue? Mechanic 2 is running out of ideas and I REALLY need my Edge back!

 

thanks!

[1004ron]

The fact that you're using "mechanic 1 & 2" suggests that you don't DIY, so I'd suggest that you find a reputable real mechanic to perform diagnostics and repair - a real mechanic would more likely solve the issue and cost less than #1 and #2.

 

There's a multitude of potential causes for a "crank no start" and without more info and fault codes all folks here would be guessing, and then to pass those "guesses" onto #1 and #2 would be futile.

How on earth did #1 think that a low oil pressure switch would prevent it from starting??????

 

 

[enigma-2]

The ECM may detect a low oil pressure signal from the sending unit and stop the engine from starting as a safeguard to prevent catastrophic internal damage.

 

1004ron is right. 'Good mechanic'.

Could also be a broken wire.

[prncssmelissa]

No update, but I did get it home from the original mechanic. I have a new mechanic that I’m going to have try and diagnose it this weekend - still not throwing any codes on an OBDII Scanner. 
 

hopeful that it’s something easy that can be fixed - in the past 14 months the head gaskets, water pump, timing chain, thermostat and oil pump have been replaced. Everything but the oil pump was done in January 2025 and worked fine until the low oil pressure issue in September. Oil pump was done in September, but nothing has changed (as in it cranks and tries to start, but doesn’t start). 
 

I’ll be sure to update when we figure it out!

 

thanks!