Mechanic question - 2011 F-150 5.0L Low oil pressure light comes on at idle in gear

[BigL]

If no noise. Very well can be a oil pressure sending unit or instrument cluster issue. What is the oil pressure reading while driving?

It's fine when driving. I'd say 3/4 of the way toward high. Only when I go from driving to stop at a light then drops to nothing. If I put it in neutral all is fine. It only happens when my idle drops under 500.

Very likely this.

Get a new sending unit as soon as possible and see if it fixes the issue.

If you were actually experiencing truly low oil pressure you’d likely already know it and would have found out in a not good way. It’s probably just a voltage issue between the relay and gauge but definitely be cautious about it.

Wouldn't surprise me if it's a voltage issue honestly. My battery light has been on for 3 years. Had a battery die and when I replaced it the light stayed on. Battery and alternator get checked anytime I take the truck in. I haven't been able to track it down and other than coming on when I start the truck, you would never know it.

But I do have a small leak around the sending unit. So will replace it and see what happens. Probably will replace the wire assembly when there also just to rule that out.