Oil Pressure Sending Unit on F150 Yammy

[Shermanator31660]

Just wondering if anyone else has had this problem with the sending unit. First start up of the day, motor fires up and oil pressure light/beep comes on and stays on. Now, if you turn the motor off right away and restart it the warning light does not come on, nor does it come on when the engine is warmed up. New oil pump in the motor so that's not it, pulled the sensor out and cleaned it, for what that was worth, it still does it! Sherm

 

[99yam40]

I believe alarm will sound if the pressure is out of spec. too little or too much

Need to test to see what it is doing.

 

[Shermanator31660]

I thought it was just a low pressure indicator. With a new pump I figured it should be good to go, do you know if you can test the pressure via that port that the sender is in?? Sherm

 

[99yam40]

the sender will be monitoring pressure, so yes that would be place to take reading of what it sees.
Rigging up a tee so you can see the pressure with gauge while the sender is still in the loop would be best
as you can tell when it is alarming and when it is not.

From what I have read there is a mapped spec in the ecu for different RPM and situations,
if it is not within that spec too high or low will bring in the alarm

 

[Shermanator31660]

So I'm guessing that when the engine is cold, the oil pressure is higher when it first pumps but as the motor warms up the pressure would go down and then no alarm? Almost makes sense, I see the sender is actually a sensor rather than the usual sending unit, and its only $250 here in Canada, what a deal! I'll have to find a pressure gauge and try and rig up that testing apparatus, thanks........Sherm