Oil drain plug leaking

[chrisracer79]

Hi folks. I've had a very slow drip coming out of the drain plug on my M20 and went to replace the plug and new crush washer (OE). I found out however that the existing plug was sized M14x1.5, NOT the standard M12. Was M12 always the standard or did someone have the hole re-tapped at some point?

Even with a new bolt and crush washer, I still have a leak.

Check out the surface of the hole...should it be concave with ridges? It appears the crush washer was properly crushed after being properly torqued. Threads look good. Not sure why the plug would be leaking at this point.

[packratbimmer]

A short term solution would be to Permatex 2 everything using another crush seal.

Also, try the thin aluminum seal - it might crush/seal more/better.

[dnguyen1963]

Smooth out that surface to help with the seal. A paper washer might seal better than a copper one in your case.

[chrisracer79]

Smooth out that surface to help with the seal. A paper washer might seal better than a copper one in your case.

some fine grit sandpaper? makes me nervous :)

I'll definitely try a thinner/softer gasket.

[jeffnhiscars]

Get a fiber washer (or 2) and don't mess with grinding or sanding as you will never flatten that working under the car. It's the threads that do most of the sealing anyway so just throw some grease on them or a small dab of permatex non hardening gasket goo

[chrisracer79]

It's interesting..I've been googling around and there are different POVs around what seals - the gasket or the threads.

Washers are cheap...I'll give it a whirl. Permatex too.

[dnguyen1963]

You guys are too nervous about this. Plug the drain hole and use a dremel with a fine sand paper wheel to polish the area. 2 min is all you need. Clean it up with some oil and you are good to go.

[packratbimmer]

get a female allen plug and temporarily loc-tite it while polishing

[staysideways]

Put some drain plug clay if they still sell it and use an aluminum washer that's a little smaller than the back of the plug.


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[Stapes]

I have my oil pan out and here's a picture of the oil plug. The surface as to be flat for the crush washer to seal.