But we supposedly have magical powers and can see over the wires. Now the op might someone will just totally guess at things. Some shops here will do it just to sell parts.
This is why I clean an engine or other equipment that uses oil, install UV dye, run for up to 30 minutes, and then do UV scan of the equipment.
Here is an example of some the engines I get in. Now where is the oil leak.
Just did a pair Hydro Gear pumps to find the leaks. Oil and dirt was everywhere. It turn out to be a $0.19 ($1.35 if shipping is included) o-ring that if you look up the pump Hydro Gear only offers a $35+ seal kit. Even though I have the seal kit on hand I rather just the one bad o-ring instead of pulling the pump from the Super Z (lots of unnecessary work avoided).
I did a Honda GX390 a couple years ago on a pressure washer where oil appeared to be leaking somewhere around the flywheel but with the UV dye the problem was traced to an oil fill cap seal and was distance from the apparent leak location.