2012 F150X2 often when driving and coming to complete stop the oil pressure gauge needle drops to 0 and the oil pressure alarm will sound. As soon as the engine revs, the pressure goes to normal, only to repeat this each time I stop. I have checked the oil level and it is full. Any ideas why this is happening?

 

Possible bad sending unit . really need to check the oil pressure with a gauge. Go from there.

 

Does the engine noise change when the oil pressure drops out? If not, change the sending unit as it's a safe bet the sender is bad.

 

same thaught here. do a manual check of the oil pressure with a check gauge such as sold in a kit at harbor tools. another taught is a sludge'd up pump pickup that slows oil flow at idle a item i had to clean many times from cheap oil used by fast oil change shops and low quality oil filters they use