Learn me Striped out oil pan drain plug

changing the oil in the S54 and thought I would go back with one of the magnetic drain plugs, looks like it is brass so of course I over tightened it and stripped the bolt or the pain (aluminum) and cannot get it out it just spins......there is not enough room to get a flat screwdriver under the head to apply pressure, so I put vise grips on it pulling down with all my might mouse power and could not get it to bite a thread, tried different angles while turning trying to get it to bite but no luck......not sure I could drill it out...my only other thought and I cringe just typing it...JB Weld that drain plug and use the removable plate in front of it to drain the oil......any other ideas???

Figure out some way to use a wheel puller or the like? If the plug is brass, and the pan is aluminum, then the pan loses that battle. Removing the whole pan may be the only option.

If it aint leaking I might try the JB weld and I'd just pick up a new pan from the junk yard before the next oil change...

Are you sure the plug is brass? Which has a lower melting point, the pan or the plug? If the plugs melts first, torch it till it bonds to the pan, then drill.

I don't think I would do the JB weld thing on an M3 track car. On a Lemons car maybe, but not a car you're putting so much care into. If you can't get the drain plug out, can you replace the oil pan? I think that's a pretty big job on the E46 but I'd rather replace the oil pan now than lose all the oil on track and have to replace the motor.

How hard is it to drop the pan?

Pushing metal chips from drilling or grinding into the engine could hurt later, drop the pan and do it right on a bench. If you're in over your head take it to someone. NAPA (and others) offer an oil pan plug repair kits, cuts new threads and they supply a new larger plug.

Dan

I think dropping the pan is your best bet. That way you can properly repair it (or replace). It's a 5 hour flat rate job, so an afternoon at home, but worth the insurance being done properly.

I'm guessing this is an expensive pan...your best bet is to use a reverse drill bit on the drain plug. It will either spin out or give you a hole you can jam something in to pull it out. Then re-tap the hole for a bigger plug (or maybe jb weld and re-tap for the same size).

You're gonna have to drop the pan to fix this in any case (unless you think you can fit all those tools in there as-as), so you might as well do it now.

First, I wouldn’t torch it for fear of caramelizing the oil. Given that removing the pan is a five hour job, I’d tap two fine chisels between the pan and the petcock to hopefully force the thread to bite in.

Here's how I would attack this:

Drill a hole about half way into the old plug. Use a wrench to keep it from spinning and thread the hole with a tap. Now you can thread a long bolt into it and have something to grab onto so you can pull down while you try to back out the plug.

Drop the pan, probably needs helicoiled now anyways.

Kenny_McCormic wrote: Drop the pan, probably needs helicoiled now anyways.

Would a helicoil work on an oil pan?

In reply to ryanty22:

Im assuming being a German car its either cast aluminum or mag, so yes it should.

No clue on removing the plug, but once it is out an oversized self tapping drain plug should fix things. It did for the striped hole in the aluminum pan on my last car.

just drill through the stupid plug. coat the drill bit in vaseline, that will catch 90% of the shavings. its brass, so no coils, just tiny chips. run a self tapping drain pulg in the hole a few times till it goes in nice. then once your all done, just leave the hole open, (drain plug out), and dump 5 quarts of cheap oil in the motor, letting it drain out as you go. the replace the plug, fill with 2nd round of cheap oil, leave old filter in, fire it up and let it idle for 5 minutes. change the filter and oil again, this time with the oil you normally use. you'll be fine. we did this weekly at the NAPA CCC i worked at. even did it to a testarosa and a porsche GT2 once.

-J0N

jmthunderbirdturbo wrote: just drill through the stupid plug. coat the drill bit in vaseline, that will catch 90% of the shavings. its brass, so no coils, just tiny chips. run a self tapping drain pulg in the hole a few times till it goes in nice. then once your all done, just leave the hole open, (drain plug out), and dump 5 quarts of cheap oil in the motor, letting it drain out as you go. the replace the plug, fill with 2nd round of cheap oil, leave old filter in, fire it up and let it idle for 5 minutes. change the filter and oil again, this time with the oil you normally use. you'll be fine. we did this weekly at the NAPA CCC i worked at. even did it to a testarosa and a porsche GT2 once. -J0N

I agree with this. Basically verbatim except use a shop vac duct taped to a straw to draw out what you can and flush a couple cans of Auto Zone ATF. It's thin and flows fast. Fill with oil, run 10 minutes, change the filter.

A Helicoiled oil drain plug hole works fine provided the seating area for the crush washer is smooth, flat and intact.

Make sure the gasket seating face of the new plug has surface area equal or greater in diameter than the corresponding face on the pan. Bear in mind also that oil in a pan is under pressure essentially equal to gravity over the depth of the oil, ie. none. So a fiber gasket works fine as well and takes a lot less torque to deform properly.