I've been trying to stop the oil leaks for years now on this car. Replaced the cam feed banjos and copper washers, sealed up the cam covers. I suspect now that the "blanking plate" on the back of the block is leaking. It has 5 or 6 7/16 bolts and it is trapezoidal in shape. Does this lead to an oil passage, or coolant? It is very oily, and the cam oil feed lines are dry, so I suspect it to be the problem. The oil is pooling on top of the bellhousing and running down all over the engine and trans.

Is it possible to change the gasket with the engine in the car?

 

I think one bolt is into an oil passage iirc (?). Others into coolant passage. The plate rusts through as it covers the coolant passage across the rear of the head. I had a few made from stainless steel when I had my tranny out a few years back. I don't know if I could find them now. It will be a pretty tight job to change it in situ. I remember thinking it could be done, but don't take my word for it. btw... the hole behind it is about 2" sq I think, with a perimeter gasket that will leak.

 

I just looked at my 1984 model-year built in June 1983 and the plate has 5, 11mm bolts, each with a locknut. Looks easy to remove the 5 bolts and then pry the plate off the head. No need to remove anything for access. Just need to have the new gasket ready.

 

That plate covers a casting hole to the coolant passages. For the life of me I can't see how you can possibly get oil leaking out if the gasket for this has failed. Surely the oil is dripping down from one of the camshaft oil feed banjos, or there is a very small hole in the copper pipe near those ? Of course, as 'slofut' says, one of the tapped holes for the securing screws may be deep enough to enter one of the oil return passages at the back of the head. This is easily sealed up with some plumbers PTFE sealing tape. Take out one of the suspected bolts and see if there is oil on the threads. If you find one with this then you know the tapped hole has broken through there. The PT0FE tape will seal it up for good. The oil in these passages is not under any pressure at all, it is oil draining back into the sump via the block.

 

If the plate is rusty around the sealing surface you can flip it around and use the good side.

 

Hello SableXJ6C,
What was the resolution to this oil leak?
I have the same situation going on.
thx,
Chuck (CB3)
Caretaker, 1982 XJ6