I have been trying to locate an oil leak on my 91 4.0 and have alwlays thought it was a rear main, which I had replaced. Unfortunately, the leak is still there. It appears that there is a sensor on the side of the pan which may be leaking. Has anyone else encountered this or am I just have a nightmare? If it is the leak, it looks like an easy fix.

 

oil tends to travel when there is a leak so it is difficult to tell where it is coming from. have you checked the valve cover gasket?

 

Yep, checked all the gskets and they are not leaking. The reaason I suspect the sensor is that, as you say the oil travels, which it appears to be doing, from the sensor back towards the rear of the engine and the main seal area.

 

if it is on the pan, then you may need to take the pan off to get to it. in order to get the pan off you may need to raise the engine, but im not for sure.

 

I don't think you'll be able to do much without lifting the engine up a bit.