When driving the oil pressure reads normal but when im idling at a light it bottoms out on the low end. What could this be?

Thx
Pete

 

Worn main bearings, cam bearings, bad oil pump. How many miles? I would suspect the bearings are shot & engine needs rebuild. Seen this plenty of times on worn engines. I would get a direct reading presure gauage & check it for sure.

 

111,000 miles. I don't hear any lifters tapping so maybe this is normal and I just never noticed it before? Only had it for a couple of months.