spotted some oil leak under the car. (see attachment) Does anyone knows if that is engine oil or transmission oil?

Looks like it is leaking from the transmission, but the oil is yellowish color like the engine oil.

 

Hard to tell from the picture. Looks like oil in color but it is also in the area of the transmission connector which has a history of leaking.

Have you pulled the engine cover to see if there are any leaks from the valve covers.

My bet is it's tranny fluid given the area but you'd best check out the back top side of the engine as well as the tranny connector. Too hard to see in the picture.

Good luck.

 

Can't tell for sure but looks like engine oil. I have other cars over the years leak oil in this location and it was usually the rear main seal. Hopefully this is not the case here. check to see if you can trace any wetness to the source. If you are lucky it is the valve cover. It can be very hard to locate the source of an oil leak because driving blows the oil to where you are seeing it.

 

I had a similar problem with my mustang.. I thought it was the tranny, but it was a result of excess crankcase pressure. Oil was pushed out of pretty much every seal on the engine and ran down the back of the engine onto the transmission, headers, etc. I would get a can of engine bright, clean the engine and watch for the leak. If I had to guess I'd say it is from the back of the valve covers, and would check the PCV system's function (ensure that vacuum line draws vaccuum, check for clogs etc).

 

It also looks like Oil to me...

When my Valve Covers were leaking, and I pulled the Oil Splash Pan and looked up at the Engine bottom, there was literally Oil all over the place.

I would pull the pan, get underneath and clean it up anyplace I can see it.

Then run it and go back in and see if you can isolate...

 

I cleaned the leaks at the bottom with a napkin, and it is definitely engine oil. Now I have to trace down where it is leaking from.

 

Here's what my Valve Cover looked like with oil (both sides were leaking, but Drivers side was the worst)...:



Also, if you had an oil/filter change recently, it's possible of a bad/misplaced Filter o-ring, or the Filter not seated right.

Look for the obvious things first, before getting totaly depressed about a possible rear seal...

 

Mine leaked in the SAME place and also leaked at the recirculator. What a pain at 40k miles. OP please check your valve cover seals as it is most probably leaking around there and running down the back, if you look to the left of your tranny leak area it looks like it ran down from there and flew over to the area you are now seeing it.