I have an oil leak in what I believe to be the distributor plug/cover/cap in my 1982 240D
Right behind the power steering below on the block
Theres a 19mm threaded plug i though was leaking but its actually the sleeve around the plug thats in the block.....any suggestions or info on how i would remove/seal the leak...

Would i just crank down on the plug assuming the collar is threaded in?
Breaking it loose was difficult.