Stripped oil pan drain bolt thread

[scubastove]

I had the rod bearings replaced in my 2002 M3 two years ago by a reputable shop in the E46 M3 world. Last year, when I went to change the oil myself, I noticed that I could not torque the drain bolt down. It would hold the oil just fine, but the bolt itself would just spin. I figured the threads may be shot and need to be helicoiled, so I brought it in to my local indie BMW shop to perform the job, along with other fluid changes. The shop informed me that they could not back the drain bolt out, it just freely spins and will not catch a thread. The only way to get the bolt out would be destructive to the oil pan, so they recommended oil pan replacement. Pretty annoying after having the rod bearings done not too long ago, and now have to drop the front subframe down again to perform nearly the same job again.

Is this accurate, is there truly no other way to get out a spinning drain bolt? would applying downward pressure while spinning, or wedging a flathead in to see if it can catch a thread? My couple-hundred-dollar oil change is now looking close to $1700.

What's more annoying is that the shop that did my rod bearings will almost certainly not honor this under any warranty work, because this would be rather hard to prove to a shop that this happened since my last service there.

[DoubleSidedTape]

If you have the oil pan out it should be easier to get the drain plug out, and then you could have it repaired, rather than needing a new pan. Still pretty annoying for sure.

[Nleeumd]

honestly, it doesn't hurt to bring this to the attention of the reputable shop? Reputation goes a long way, and while you might be right about them not honoring their work, the worst place you get is back where you started.

[scubastove]

honestly, it doesn't hurt to bring this to the attention of the reputable shop? Reputation goes a long way, and while you might be right about them not honoring their work, the worst place you get is back where you started.

I did call them up about this last year when I found the drain bolt was spinning. They mentioned I could bring it in and they would take a look/helicoil it there, but the shop is a few hours away from home and my car is on a lift local to me. And it's not like the reputable shop will front the bill for this parts/labor without them seeing it, and determining if it is something they would cover. I feel a little cornered and wasn't sure the best route to go.

[sapote]

The shop informed me that they could not back the drain bolt out, it just freely spins and will not catch a thread. The only way to get the bolt out would be destructive to the oil pan, so they recommended oil pan replacement

Shop didn't offer any creative ideas. I would try these before the removing the pan:
1. Grip vise on the drain bolt, then while pulling the bolt out HARD, like lifting 20 lbs weight, turn the bolt CCW to catch the threads. This should work but if after 10 minutes and not work, then next
2. Drill the bolt at perfect center (keep it from rotating with other nose pliers or something) start with small bit, then get to larger bit and do this careful then the bolt reduced to thin sleeve, then with pliers crush it inward and turn it out or pull out. Try to drill to the pan threads.

[heinzboehmer]

You can definitely get the drain plug out without removing the pan, even if it means drilling it out or otherwise destroying it.

Repairing the pan with a time sert is the way to go btw, much better than a helicoil. Just make sure you get the appropriate length inserts (9.2 mm). Had to do this myself not too long ago: https://nam3forum.com/forums/forum/m...162#post156162

[scubastove]

You can definitely get the drain plug out without removing the pan, even if it means drilling it out or otherwise destroying it.

Repairing the pan with a time sert is the way to go btw, much better than a helicoil. Just make sure you get the appropriate length inserts (9.2 mm). Had to do this myself not too long ago: https://nam3forum.com/forums/forum/m...162#post156162

I did see your thread for this while looking up my issue. But I think you were able to get your bolt plug out without issue? I just don't have the tools/place to do this myself right now. So you're saying they should be able to remove (and likely destroy) the drain plug but leave the oil pan intact? Is there anything I can recommend the shop try specifically?

[heinzboehmer]

So you're saying they should be able to remove (and likely destroy) the drain plug but leave the oil pan intact?

I think so, pan is aluminum so it shouldn't be too hard to force the drain plug out. I would at least try

Is there anything I can recommend the shop try specifically?

Sapote's recommendations are what I would do too. Just be careful if drilling into the bolt. There isn't too much stuff above it, but you don't want them to hit an oil line or connecting rod. Oil pan is for sure coming out if they do.

[JayVee]

I did this same thing due to a bad magnetic drain plug. I was able to remove the bolt, but I did use a Time-Sert oil pan repair kit. The repair was fantastic and very solid, it uses a steel insert that mechanically locks into the oil pan. It also retains the OEM threads and you can use the original drain plug.

Coming from an engineer, this is the best solution short of oil pan replacement.

[scubastove]

I did this same thing due to a bad magnetic drain plug. I was able to remove the bolt, but I did use a Time-Sert oil pan repair kit. The repair was fantastic and very solid, it uses a steel insert that mechanically locks into the oil pan. It also retains the OEM threads and you can use the original drain plug.

Coming from an engineer, this the best solution short of oil pan replacement.

according to the shop they are unable to remove the plug. That is the main issue in the way

[Da Jemster]

I "3rd" on Time-Sert. I've used it on 3 cars now. No leaks.

[Halftim3]

My oil pan bolt/threads also kept spinning freely on a previous oil change so I plugged it with some RTV and would do oil changes through the strainer area for about 3 oil changes and timed it with my local shop to do my rod bearing job, oil change, and oil pan drain bolt repair. He repaired it by welding a bung which works perfectly and is IMO way better than buying a new oil pan. It doesn't look good, but no one sees it anyway.

[Da Jemster]

spot weld a longer bolt and see if you can get leverage

[George Hill]

Cut the head off with a grinder, then hammer the threaded shaft "up" into the the crankcase. Remove the oil pump pickup strainer and fish it out.

Repair with a time sert.

[eacmen]

Cut the head off with a grinder, then hammer the threaded shaft "up" into the the crankcase. Remove the oil pump pickup strainer and fish it out.

Repair with a time sert.

This.

Might need new gasket for that oil pump strainer.