Oil leak?

[och]

So I'm in the middle of timing belt replacement, and I discovered that the drivers bottom side of my engine is covered with thick residue - perhaps mixture of oil and dirt? It is very similar to the picture below. Where can that be coming from?

 

[mshawari1]

May be that is your PS pump is leaking … so forget about it …. ​

 

[och]

Well, but the PS pump is on the other side. If you look on this picture, most of the oil is on the right side, and the PS pump is on the left side.

 

[cribbj]

Have you checked that the sheet metal sump to upper oil pan bolts are torqued up OK?

Or perhaps they're torqued OK, but someone who owned the car before you dropped the sump and didn't reseal it too well? Does it look like anyone has dropped that sump recently? (is there silicone oozing out around it?)

Possibly the valve cover is leaking and the oil is dripping down on that side?

Lastly, Toyota oil pressure sensors are known to leak where they screw into the filter head/housing.

Kinda tough to tell from that one photo where it's coming from.