I have a leak on the side of the head coming from this part, but don't know what this part is. What is it and is there a seal for it or is it metal to metal?
Thanks!

 

Is it coolant leaking out? It looks like you're pointing at the coolant temperature sensor (ECT). I think there is an o-ring seal where it screws into the head. If coolant is coming through the plastic piece on the back (not the gap where the o-ring is), the sensor itself is bad.

If it's oil, it's real common for the cam plug (the large round plastic plug at the end of the exhaust cam) to leak and have oil drip down into that area. Or the VTEC solenoid gaskets, which can be hard to spot because it may only leak (but then it leaks a lot) when VTEC is engaged.

 

This ^^^^^^. Well said mk378

 

mk378, looks to be oil so.........to be on the safe side, I guess i will replace the cam plug & the solenoid gaskets at the same time.
Thank you for your help!