O-ring sucked into engine $$$$

[Ernstww]

I’m curious if anyone has heard of this happening.

I’ve had my 1994 540i for 13 years. This incident happened shortly after getting the car in 2005. I took it to a mechanic that I had grown to trust over the years with my domestic vehicles, I didn’t think much of it as it was a simple oil change.

About 2000 km later a pronounced ticking sound developed. I went back to the mechanic, he listened for a moment and said in a slightly concerned voice, ‘Take it to a BMW specialist’. I did that. They dropped the oil pan and discovered chopped up fragments of o-ring from the oil canister. Upon checking the canister they found the filter and the inner sleeve had not been assembled correctly and that the o-rings had been drawn into the engine where they were chopped up and eventually logged in various small galleries starving critical components of oil.

Over $15k and one lawsuit later I had a new block and rebuilt heads. The insurance company representing the mechanic accused me of scamming to get rid of the Nikasil block. That would have been a great idea although he was wrong, I'm not that Machiavellian. All in all, I was out of pocket a few grand but came away with a new block that still running today.

Since then I have always been a little nervous about that filter canister. Has anyone heard of this or was I just unlucky?

[Mykk]

I suppose anything is possible, but my first thought is that it's not likely. There aren't any avenues or channels an o- ring could travel as whole from the canister back to the enginend without getting snagged or simply just too large to fit. And if, if one did make to the engine side the only "meat grinder" would be the oil pump and it has a screen on the pickup tube to prevent any debris from entering the oil system. Any photos from the ordeal?

[ross1]

I suppose anything is possible, but my first thought is that it's not likely. There aren't any avenues or channels an o- ring could travel as whole from the canister back to the enginend without getting snagged or simply just too large to fit. And if, if one did make to the engine side the only "meat grinder" would be the oil pump and it has a screen on the pickup tube to prevent any debris from entering the oil system. Any photos from the ordeal?

Initially my thoughts too BUT if the ring were cut and had an end dangling and inside of the filter I could see it getting to the pump and since it's already past the screen this is, however unlikely, plausible, barely. One would almost have to deliberately place it there.
I am nervous every time I tighten one of those canisters as it always feels like the O-ring is dragging and stretching. Just as it snugs up I always back it off a bit and re-tighten, it feels better after relieving the tension. Maybe it's my imagination.

Interestingly enough our OP's first post here was regarding Nikasil engines. Yeah, I'm skeptical too.

EDIT, again: using my sometime rudimentary reading skills I see the O-rings of the inner sleeve, the dildo, are the suspects. I can see that happening. Perhaps not assembled incorrectly as speculated but just old and failed when inserting. Aftermarket filters don't always come with all the seal rings so lots of them in service are very old.