This is my project car, having repaired many issues. The engine runs great and does not smoke out the exhaust.
My big problem is oil leaks, oil gets on the mufflers and smells. So far, I have replaced the PCV valve, breather filter canister and oil pan gasket. I have stopped the leaking at the oil pan. But oil pours out the rear main when the engine is running for a while after stopping it. There is vacuum at the PCV valve, have not been able to find any vacuum leaks on the crank case.
Can the rear main oil seal be replaced without removing the engine? If so, how?
I understand that there must be a negative pressure in the crank case, any other ideas on what to check.
Thank you for your help.
Danny

 

I am surprised at that.

The MAIN cause of leaks that BLAME the rear main, are from the 2 cam cover rear "D" rubbers. The oil will POUR out of them after shutdown and run down the block, and out around the tin pan covering the flywheel.

The 2 oil switches at the rear are also very high on the cause list.

Then comes the 2 banjo oil feed bolts at the rear of the cam blocks, BUT, if they have NOT been messed with, they will NOT leak. Great care here is needed, as the threads in the alloy cam blocks will strip in a heartbeat.

The gasket between the engine block and the oil filter alloy housing is also another leaker, as the oil will find its way inside that tin pan.

I would remove that pan/cover, clean up inside the area between the flywheel and the engine block. Run the engine, shut it down, clamber under it and have a look see. You will need a GOOD strong LED torch. If there is oil way up inside, at the main bearing cap, you got main seal leakage. That seal is a rare thing to leak in the big scheme of things. It dries out from lack of use, I am talking years here, and may "weep" at start up, and then take up with the addition of fresh oil.

 

I have already replaced the two oil sender units. My next step is to replace the half-moon rubber seals which are leaking. I am not sure about the banjo oil feed bolts. I have not checked them.
Thank you

 

OK.

Those banjo bolts are RARE leakers, and mostly the D rubber is the root cause of them getting blamed. Access is very tight, and I would NOT touch them at this stage of the procedings. The banjo bolt is really too short, and only picks up about 4 threads with the THIN OE copper washers. There is PLENTY of thread inside the camblock, so longer banjo bolts (readily available from Jag PartsPeople) are the best replacement IF you really feel the need to actually remove them. I would NOT at this stage, as I said.

In real serious cases the o/ring on the distributor base can leak, oil runs down the centre cover edges, off the rear, around the block, and out the lip of the tin pan.

None of my V12's run a PCV system. The crankcase is vented to the outside, and I have NO oil leaks at all. I also remove that cannister filter in the snout at the front of the LH cylinder head, as it can clog and cause other issues. I know you have renewed it, just saying.