I just recently picked up a 95 4runner and everything was going cool except for a small oil leak. i checked it out and had my mechanic buddy look at it and told me that it was coming from the back of the valve cover. he said I could just try to tighten it up and if it doesn't work he can help me replace the gasket. so I bring it back home and park it in the driveway only to come back later and there was a little puddle of both oil and coolant under the truck. I looked at the back valve cover where the oil was leaking from and did not see any signs of coolant there so I have no idea. it was all over the under of the car dripping but I can't see where its coming from... what could be causing this?

 

Sounds like you might need to light the torch.

 

At least on the 3VZ engine , there is an upside down U shaped coolant hose hiding in the back, best viewing angle is from the passenger side with a flash light.

 

It doesn't look like the two have been mixed. looks as if separate leaks because the coolant and oil are both clean