I am loosing coolant so decided to investigate, took me a couple of hours to remove the engine cover, eventually just ripped the thing off, I noticed quite a bit of oil build up in there, however topped the coolant off and went underneath, I could see coolant dripping from oil filter area there what looks like a drain plug of some kind to the left of the filter housing, any ideas what it could be.

 

That plug is a part of the front cover and I believe is used for an oil cooler (which your truck probably doesn't have). I use that port for oil pressure gauge. Your coolant leak is probably from above. How does it look near the water pump?

 

Thanks for your reply, I will investigate further and report back.

 

pressure test your coolant system so that you will know if the leak is the water pump or the timing case cover