Oil Drain Plug Stripped ... anyone use Time Sert?

[F87source]

Just wanted to throw in my 2 cents because I have helped quite a few (maybe 5+ people now directly on this forum) people with the S55 aluminium oil pan fix stripped threads. I have helped them do both helicoils and timeserts.

Personally I would not use a time sert for this application, because of how thin the walls on the pan are. Yes a time sert is stronger than a helicoil - however that strength doesn't mean much if the walls of the pan is simply too thin.

So here is my logic, if you look at the bmw s55 oil pan, you will notice that the drain plug hole is kind of like a tube going up into the pan, it isn't a thick block of metal that the drain threads are tapped into, but rather a very thin tube. These side walls stock are probably in the couple mm range, so it is already paper thin, there is knotch cut out as well further weakening the strength of the hole. All this combined with the fact that the metal is aluminium and not steel means it is very weak.

Like this (don't let the curvature of the hole fool you, it is extremely thin, also this might not be the s55, it likely is the n55 pan but the hole designs are very similar):




This (below) is the m5 pan, and it is representative of what the s55 pan's drain hole looks like but slightly different positioning and slightly different side walls. There is also a knotch on the s55 pan as well further weakening the material there.





So in my opinion, it is far superior to use a helicoil in this repair. Because a helicoil only requires the hole to be drilled out 0.3 mm larger than stock, that is 0.15 mm per side (radius increase), which is a fraction of a mm and literally nothing. This will give you the best chance of success, and removes the least amount of material possible keeping as much material there as possible meaning that hole stays strong. Whereas a timesert forces you to remove much more material and you have to cut a chamfer into it for the insert to sit flush, this reduces the chance of success because the hole can crumble while you drill it out + the side walls are even thinner now.



In terms of strength, a helicoils will provide you with the same amount of strength as the stock threads, if not more because the insert is stainless steel and put into a larger hole. Sure it isn't as strong as a timesert but I would be willing to say that if you factor in the sidewall thickness of both solutions, the helicoil would be on par if not stronger. Galling is also not a concern because its in the oil drain plug, this is constantly lubricated so there shouldn't be a worry there.


So this is why I think a helicoil is the right choice for this job, bmw even recommends helicoils for thread repairs in ISTA.

[gerri]

Originally Posted by F87source

In terms of strength, a helicoils will provide you with the same amount of strength as the stock threads, if not more because the insert is stainless steel and put into a larger hole. Sure it isn't as strong as a timesert but I would be willing to say that if you factor in the sidewall thickness of both solutions, the helicoil would be on par if not stronger. Galling is also not a concern because its in the oil drain plug, this is constantly lubricated so there shouldn't be a worry there.


So this is why I think a helicoil is the right choice for this job, bmw even recommends helicoils for thread repairs in ISTA.

I agree with what you say. In my opinion, however, the problem is that these threads (helicoil or timesert) close the oil drain channel created on the threaded riser and do not allow all the used oil to come out. I don't know what the inside of the S55 oil pan looks like, but if it's like the M5 in the picture, the oil won't all come out.

[F87source]

Originally Posted by gerri

I agree with what you say. In my opinion, however, the problem is that these threads (helicoil or timesert) close the oil drain channel created on the threaded riser and do not allow all the used oil to come out. I don't know what the inside of the S55 oil pan looks like, but if it's like the M5 in the picture, the oil won't all come out.

You can get a 0.5D helicoil insert that perfectly fits inside of the threads and doesn't obstruct anything. There are a pretty wide selection of insert lengths too, so the repair will be fine. Iirc that's what the individuals who I helped used.

[Samf82m4]

Originally Posted by Vandaljimenez

All BMW dealerships also have a repair kit for this. Of which they drill in a bigger thread size, and provide you with a new drain bolt and washers. It’s extremely common, and cheaper than replacing your whole oil pan. The repair kit they use also blows compressed air through the engine to get rid of metal shavings during the repair process. The new bolt would also have a higher torque yield for what I understand. I would just have anyone here with this issue, send their car to their nearest bmw dealership, and let them repair it.

Surprised the dealership would use a repair kit instead of handing over a crazy bill lol. My threads are messed up after my last oil change which is crazy because I used my torque wrench and tightened down to spec. I brought it to an indy show and they wouldn't do the helicoil or timesert solution. I guess I'll bring it to the dealership for the repair.

[Vandaljimenez]

Originally Posted by Samf82m4

Surprised the dealership would use a repair kit instead of handing over a crazy bill lol. My threads are messed up after my last oil change which is crazy because I used my torque wrench and tightened down to spec. I brought it to an indy show and they wouldn't do the helicoil or timesert solution. I guess I'll bring it to the dealership for the repair.

Yeah man, unfortunately somewhere along the line of oil changes your car has had, someone has over torqued your oil pan bolt, they don’t strip for no reason. It happens to the best of us. I’m a 4th owner of my F80, and was left with the bullshit. Bear in mind the kit the dealer uses involves them drilling out the stripped threads, tapping new threads, and using a new (bigger) bolt from now on.
Which means totally diff part number for washers and drain bolt.

[F87source]

Originally Posted by Samf82m4

Surprised the dealership would use a repair kit instead of handing over a crazy bill lol. My threads are messed up after my last oil change which is crazy because I used my torque wrench and tightened down to spec. I brought it to an indy show and they wouldn't do the helicoil or timesert solution. I guess I'll bring it to the dealership for the repair.

Bmw specifies helicoils are acceptable for thread repairs on the sub frame and even has guides on how to use one. So theyre not garbage, it's just people don't understand and know how to use them.

[NORAGRETS]

Well I cursed myself just changed the oil and now it’s leaking

Anyone think this will work?

M12.1-1.5 x 15mm Oversize Piggyback Oil Drain Plug, Stainless Steel Self Tapping Oil Pan Thread Repair Kit https://a.co/d/6RHTfNa

[MemeLordCS]

So anyway I also joined the stripped drain plug club, however I dont think it was my fault since I was hand tightening it and was using a brand new bolt, it went half way in with hand, then I used a wrench and it started spinning, that's when I knew it was over ��.

My assumption is previous owner had it rethreaded at some point and it only worked with the same old bolt but the new bolt screwed it up in some way.

Solution for now, I tapped it with the same size tap, some of the threads came out. Poured an entire quart of oil to basically wash out the engine and any shavings. I used the old bolt again and its closed now. I think it will leak very slowly over time so this is a temporary solution.

Currently will take it to the dealer for next oil change and see if they can do the repair kit as mentioned in this thread, but I'll have a new oil pan on order soon as well and get the crankhub done in one go.

[NORAGRETS]

I just had my BMW tech buddy do the repair for me. He said its SUPER SUPER common and they actually keep time serts in stock for this exact thing. He said time sert should hold for a long time, but down the line "be prepared" to replace the pan. I was expecting that anyways so yeap.

But it works!