If it has oil pressure now and didn't then it sounds like the pump was
sucking air for some reason. That could be that the oil is not
getting back to the pan fast enough. Or the pickup fell off the oil
pump. Another possible explanation is that the relief valve on the
pump got stuck open for some reason.

Eisboch wrote:
"Big gus" wrote in message
...
Hi and thanks for the speedy response

its was just the heads and a valve job. the head gaskets were
replaced.

the engine was warm when I changed the oil filter.

the oil pressure started to drop after I put the engine under a load.
3500 RPM's and the oil pressure dropped to zero and the red warning
light on the dash board went off


Hate it when that happens. Forget everything I suggested. You have a
problem.

Eisboch