water leaking from valve cover

new rebuilt 70b engine, had running several times, today finally stopped gas from overflow tubes and discover water leaking from the valve cover above plug #3 , engine to hot to check oil, why would this be happening and where do I start? Thank you Dennis ps if I take off the valve cover a drop of water beads over the #3 plug on the surface of the cyc. head flows down to the #3 plug, then to the ground

You have a cracked head. Something your rebuilder should have checked for. The FIRST thing I do with MGB heads is check for any cracks in the head between 2&3.

I have it inspected many years ago then it stat in my closet for years before I installed it, when inspected way back I was told it was fine.Dennis70

Could the head gasket not be on correctly, I think there is a top side and bottom, I ofter wondered if I did that in right orderDennis70

Dennis, there isn't any way around it. The cast iron is cracked and the head will have to be replaced. :-(

Before you use another one have it tanked and magnafluxed.

Jack

I have, for many years, been servicing two cars with bad heads. One is a 79 that came with a 1500 head that seeps through the casting right above #3; the other is a 72 with a crack running from #2 exhaust spring straight out the cover and down to the head face. Both cars usually have a single drop of AF hanging there. Since both engines run fine and do not lose measurable fluids, we just leave them alone - about 20 years on the 72. While I certainly wouldn't rebuild a head like that, neither would I change it if it's not dumping coolant. That's what stopleak is for! (No, I never put any in either of these cars)

FRM

I am the same way, small crack just left and above plug #2. Small drops of AF and a general dampness in the area. Fluid lose is barely detectable and I just check radiator level every once in a while but car runs good.