Toyota pickup oil leak

I have a 1986 Toyota pickup 22R engine. I recently had a big oil leak. I took it to the shop. The injected teh yellow dye to find it. They drove it. It didn’t leak. They drove it again and it sprayed all over under the hood. They couldn’t pinpoint the source of the yellow. The mechanic doesn’t just want to change the usual suspects, so he gave it back to me. I’m going to drive around town, then check for yellow leaking each time I stop. Hopefully I’ll catch it before it sprays all over. Can you help me figure out what may be leaking?

If your mechanic who laid his eyes upon your truck can’t find it then it’s going to be very difficult for the leak to be found over the internet.

Big oil leak, but can’t find it.??

It (oil?) sprayed all over under the hood.

I’m going to suggest you have a back pressure problem.

Check the PCV and hose for vacuum.

Check the EGR valve. You’ll need a scan tool for this.