Hi everyone. If this is too long for my first post, just let me know.

I am new here, first time poster, long time reader. I picked up an 2011 X5 50i with 118k miles on it about a month ago and have spent hours pouring over this forum. Thanks for the all the info! There appears to be a lot of knowledge here so hopefully someone has some insight on my issue.

I've researched a lot on the N63, checked the recalls, and confirmed with BMWNA that all the repairs that needed to be done were completed. I also have the Carfax dating back to the original sale from the dealership showing a lot of work completed under warranty or recall.

I have situation that I wanted to see if anyone else has ever run into. Sorry for the long read but hopefully all the info here will help.

Long story short: Can a botched oil change cause a failure of the rear main seal?

Original Oil change

-I knew of the oil issues with the 2011 X5 so I wanted to make sure to change the oil soon after I picked it up so I would have fresh oil from the start.

I went to a place that I have been using for years (yes I now know I should have just gone to BMW) but I know the manager and the techs so I felt comfortable going.

I looked under the car well when I picked it up and there were so signs of any leaks. I asked the techs to take a close look underneath to make sure there wasn't anything I was missing.

They said the underside was extremely clean with no signs of any leaks from anyplace and no sign of old or leaks. The tech even commented about how clean it was considering that it is 11 years old.

During the oil change the tech was standing in front of me with the oil filter housing and oil filter in his hand and I could see he was struggling to get the oil filter into the housing. He was trying to shove the two together. I asked him if there was an issue and he said it was just tough to put together since it was new. I figured he was correct and left it at that.

Return Visit 1

-Two days later there was oil under my car in the driveway. I went back right away and had them look at it. I was told the oil filter housing wasn't seated correctly. They reseated it and I was on my way.

Return Vist 2

-Two days later oil was still pooling under my car. I went back again and this time they said it appeared to be a problem with the drain plug. They replaced that.

Return Vist 3

-For 4-5 days everything seemed to be good and then I looked closer and I could see oil pooling under the filter. I returned again and was told this was just residual from the previous leaks. They cleaned up the underside and things seemed ok for about a week

Return Vist 4

-This is where things got worse. I took a drive to Big Bear which is about 100 miles away from me. I took the freeway and stopped about 75 miles in to get gas. After the fill up I could see a small pool of oil under the car. I crawled under and could see it leaking from under the oil filter. I checked on the oil level on the screen. It had been full when I left but now was about a quarter of the way down to the "min" mark. I drove the rest of the way and then turned around to come home, all the while keeping and eye on the oil. By the time I got back (about 200 miles round trip) the oil level was a little bit above the "min" level.

I went right to the oil change place and this time they they said the oil leak was from the rear main seal.

At this point I started a claim with the company.

All of this seemed very odd since there were no leaks at all when I took it in originally.

Mechanic 1-

I took it my main mechanic I've used for years to get it checked out and he confirmed it was the rear main seal leaking. He checked the oil filter and found that it was missing a part. The small part that sits in the bottom was gone. He said they probably threw that away with the old oil filter and didnt know. He also said that it was "possible" that this caused the oil pressure to be incorrect and could have caused the rear mean seal to blow out but couldn't say for sure.

Claim call:

I spoke with claims who got the manager on the phone. I told her the issue with the mistake in the oil filter and she said that sounded like a mistake and they would "take care of paying for the repair".

Mechanic 2:

-I took it to a mechanic who was recommended to my for a 2nd opinion. I explained everything and they said the same thing: It's "possible" that the bad oil change could cause the rear main seal to fail. After they looked at it, the mechanic there called a BMW contact he as in Germany and was told there is a "50/50" chance that the bad oil change caused the rear main seal failure.

I had this mechanic repair the rear main seal and got everything buttoned up and cleaned up. No issues for the last week and not a single drop of oil.

Claim call 2:
-I sent photos of the old oil filter and passed along the info about the oil change being a probable cause of the rear main seal and how the store manager had agreed that her tech had made a mistake in the oil change.

At this point I was told that my claim had been denied and that when I was told they would "cover the cost of the repair" they actually meant they would cover the cost of replacing the oil filter housing.

So, here I am wondering if anyone has any insight into this and has had this happen. If I can provide some additional info as to the bad oil change being the cause of the rear main seal going out then I have a good chance of getting them to reimburse me for the cost of the repair which was $1500.