MyE28.com

First, the good news: my m20 rebuild project is nearly complete. The motor has started and I don't have too many parts or pieces left over.

Now the bad news: it seems that oil is leaking from both the front and rear oil galley plugs. The original plugs were removed when the block was cleaned. BMW OEM plugs were reinstalled during assembly. The plugs were cooled to about 0° f and both the plugs and the openings in the block were coated with permatex aircraft sealant. The plugs were then carefully and gently seated into the block using a small Hammer and a drift until the plugs were flush with the surface of the block.

Unfortunately, it appears although I've not taken off the water pump or removed the transmission and the rear main seal retainer, that both plugs are leaking oil somewhat significantly.

I've been told that green loctite would have been advisable rather than the permatex aircraft sealant. I was unable however to find any information as to how the factory would have installed these plugs.

I am am mentally preparing myself to begin the disassembly process to address this problem. While I do, I thought I would inquire with the e28 hive mind as to the proper procedure for ensuring that these galley plugs don't leak upon reassembly.

I've thought about tapping the block for an npt plug. However, it's my understanding that it's a 12 mm opening which is about 1/32nd of an inch too big for a 1/4 npt plug and I'm not sure I want to drill it for a 3/8 while still predominantly assembled and in the vehicle..

Thoughts?

First thing to do is verify the source of the leak. Most common issue is rocker cutout plugs and the cam seal housing oring. These can be improperly installed or damaged pretty easily.

If it is oil galley plugs, I've never removed them. You have plenty of options to seal them up. Even JB Weld would work, provided that the surface is thoroughly degreased.

Do they seat against a lip or can they be pushed in deeper than they are currently?