92 Roadmaster 5.7-Oil Pressure Indicator

2 days before she returned to school, my daughter's 92 Roadmaster tranny went-had it replaced, and about a month after that, we now get what we THINK is a false oil pressure warning.

OP is normal during cold start and warmup. Once it hits operating temp, the oil pressure at idle hovers around 20, with erratic dips down to zero, which triggers the low oil pressure warning. This happens only at idle, and raising the RPM will remedy it...the oil level is FULL and verified three times, the oil is clean, and there are no abnormal noises indicating oil starvation.

Is the sender or oil pump a chronic issue? Is it easy to check oil pressure quickly without major disassembly?

Thanks in advance and Happy New Year to all....

The only way to see what's what is attach a mechanical gage to the op sender port for a direct reading.

Thanks Max, that is what I am going to attempt early next week.

I was wondering if this is chronic in the 5.7.. I do remember changing the sender unit once before.