Leak around the top/back of the motor

Recently changed the starter on my 99 tacoma. While doing so I noticed where oil or some liquid had been leaking down the back right side of the block. Bad part about it is that I can't see where I believe the leak is located, so it's hard to tell if it's leaking around the head or not (which may be the only possibility). It is definitely starting at the top of the motor but the I don't have a definite cause/location. The truck has 238k on it so I am hoping it's not a serious issue.

Has anyone had this issue before or know of something that could possibly be wrong? I have been keeping a check on my fluid levels and they all seem to be fine. So I am also kinda wondering if it is even a serious issue as long as I'm not running out of oil or something significant.

Thanks in advance for any help or information that you might have.

 

I'd bet money it's the valve cover gaskets and rear cam cover seals. I see it's a 3.4, so that's par for the course on this engine. If you opt to do the work, attention to detail, proper cleaning of gasket mating surfaces and the use of Toyota FIPG gasket former is very important to prevent a leak again. New spark plug tube seals and a new PCV valve would also be recommended. You'll need intake plenum gaskets. It's not incredibly hard but it's not a fun job either.

I just pulled a 3.4L out o fa 2000 Tacoma that was leaking on the drivers side rear of the valve cover gasket / cam cover seal.

 

Agree ^^^^

My 3.4 was the same way when I bought it with 147,xxx miles. I did the valve cover gaskets,spark plug tube seals rear cam caps and intake manifold gaskets then cleaned the entire engine with degreaser. Engine has been bone dry now for more than 10k miles..