[DannyM235]

Hey guys I recently purchased a 2016 BMW M235i with 30,000 miles on it. I've owned it for about four months now, I purchased the car from a used car dealer in California and had it shipped down to Texas. When I received it I put it up on my ramps and noticed that the undercarriage cover had a lot of oil on it. So I then proceeded to remove the cover and degrease it and pressure wash it. I literally used a whole gallon of degreaser to try and get out all the oil that was in embedded into the fibers of the cover. I then let it dry overnight and reinstalled it, this was a few months back when I did this. Since the time of me owning it I haven't done an oil change on it and have only put 2000 miles on the vehicle so far.

So this week I decided I was going to do the oil change and purchased the OEM BMW 0W-30 oil change kit from FCP euro. This morning I decided to do the oil change. While removing the oil drain plug I noticed there was some resistance at around the halfway mark removing the bolt it wasn't much so I didn't think much about it at first. I let the oil drain for about an hour and then proceeded to put the new crush washer on the drain plug and replace it back on the oil pan. I threaded it in by hand like I always do on all y vehicle and then proceeded to tighten it down with a 17 mm socket and a 3/8" ratchet. Once again at around the halfway mark I noticed some resistance it wasn't much and after a turn or two it went back to feeling normal so I proceeded to tighten down the drain plug once it was seated with the oil pan. I the noticed it wouldn't stop spinning and I was never able to torque it down to the 25nm. I then realized that whoever had done the oil change last cross threaded the oil pan with the drain plug. I then decided to try and remove the plug so I could get a replacement and possibly try again, but I would not back out. I had to get a pair of vice grips and clamp it on the drain plug and put downward pressure while at the same time rotating it to back it out. I was finally able to get it out after about half an hour of trying. Once I got it out I noticed there were filings from the oil pan on the drain plug. I then cleaned the threads of the oil pan and took a look at it from directory under with a flashlight and saw that the threads were damaged. I went to BMW to pick up a new drain plug and an oversized drain plug that the parts guy said they also had in stock, which he stated the BMW technicians use when this happens. I got the exact measurements of the OEM plug and found that it was a M12x1.5 and the oversized plug I also purchased from BMW was a M14x1.5. After some research on the issue I decided to get a tap in the OEM size of M12x1.5 and proceeded to try and clean up the threads on the oil pan instead of retapping it to the larger drain plug's size. I used some grease on the taps channels to catch the shavings. After going back an forth a few times and cleaning and re greasing the tap I was able to clean up the threads and use the new OEM drain plug with the new crush washer after confirming it would go in and out by hand several times. I then lightly tightened it down by hand because I didn't want to attempt to torque it down to specs and possibly cause it to cross thread again. I did get a cheap bottle of synthetic 5W-30 at a local auto parts store to test if it doesn't leak overnight and to flush out any filings that could be in the oil pan before putting in the OEM 0W-30 oil.

My question is do any of you know if the oil pan is under pressure during normal operation. If so at what psi, or is it not under any pressure when ? I am afraid that I might be driving one day and all the oil might come spewing out of the drain hole because the drain plug is not tightened down to specs. I was wondering if you all suggest I re tap the drain pan hole to the next size up which would be a M13x1.5 instead of the M14x1.5 that the dealer sold me. I am afraid that jumping from a M12x1.5 to a M14x1.5 might be too large of a jump and end up leaving me with little material to work with and possibly leading me to have to replace the entire oil pan. Which I was quoted $1800 to $2000 at my local BMW dealer today. I was also wondering if I should just put a few turns of Teflon tape on the drain plug threads and hand tightening it to create a better seal instead of considering re taping the oil pan to the next size up. I was considering removing the oil pan and taking it to a machine shop to have them repair it professionally. But after researching I found out that I would either have to drop the entire front suspension or pull the engine out to remove the oil pan and I am not ready to take on that kind of job. Any help would be greatly appreciated guys, sorry for the long post I just thought I should let you know the story behind the issue. I can get photos if needed of the oil pan drain hole tomorrow morning if needed.