I have a the 3.0L in my truck, it was rebuilt by Toyota 8K miles ago under the head gasket recall. When I start it up after it sits all night and gets cold, it has plenty of good oil pressure on the gauge, after it heats up a bit the oil pressure drops almost completely out, on the gauge at least.

It doesn't knock or tick at all and I can see plenty of oil moving around in the head when I take the oil cap off, when I rev it oil will fly right out of the cap hole with the cap off. This is when it's hot and the gauge shows almost no pressure.

Is this most likely the sender, or could my oil pump be shot? I don't think an oil pump would just cut out like that, if it was bad it would just be bad all the time right? Would Toyota have used the same oil pump on the rebuild, that came off the old engine? It was rebuilt by them at 188K and now has 196K.

I have heard that the pressure senders do go bad on these things, and if they used the old one when they did the rebuild it's not hard to believe it's bad. I just hope it's not the oil pump.

Any suggestions would be great.

Thanks.