I got my 340iX in 2022 and took as good care of it as I could, changing the oil early and regularly and doing my best to keep on top of any preventative maintenance. The car served me very well with no issues up until February of last year when it was at 104034km or 64643mi, with an oil change done at 100000km and a service appointment scheduled for the coming weeks. I was driving it home from work when suddenly the oil pressure warning came on, and disappeared almost immediately. I pulled over, killed the engine and checked the car sensor values with my Icom cable stowed in the car. The sensor values were reading normal, the oil light was still off, and I felt it was passable enough to slowly limp the car home (was NOT in limp mode) the remaining ~1km. When I went to start the engine in the morning, it was making a loud noise - I already had lifter tick, but this sounded like my lifter tick took steroids overnight; this sounded a lot worse. I killed the engine and had it towed to an indy BMW shop. They drained the oil and told me the car only had 3L in it rather than 6.5, and found “large metal chunks” in the oil drainage. They were absolutely certain that I somehow only put 3L into the engine, which is ridiculous. I had replaced the oil about 4,000km before this incident, and with absolute certainty filled the car with the correct amount. I think that the car potentially burned a lot of oil as it was idling, as I did unfortunately extensively idle fairly often while hanging out or showing the car off in parking lots - probably really stupid of me. There is no sign of an oil leak anywhere, not even an oil slick in my designated parking space, so I’m inclined to believe this is what happened, although it does throw me a bit that the car was running with 3L of oil for god knows how long without the oil level computer giving me any sort of warning (it worked well in the past to warn me to top up the oil).
The indy shop quoted me for an engine replacement at $16,300 (~$8,000 for engine, ~$4k labour, the rest tax). The thing is they didn’t do any further diagnosis to confirm the source of the issue, all they did was drain the oil and check the oil pan. I’m wondering if there’s anything further that I can do myself to check for damaged areas and determine if this engine is possibly repairable in a rebuild. I had a colleague’s mechanic friend friend take a look (which is when I shot the video below), but he looked at it even less than the indy shop and spat out a seemingly arbitrary quote of $25,000 altogether for an engine replacement. Not cool. I’ve unfortunately had this car on my back burner since then as I’ve had some personal issues come up that needed to be taken care of, but I’m ready to get this job done now. Before I make any phone calls to shops, though, I’d like to get a better picture of the problem for myself.
Even if a rebuild would be $15k, I’d rather pay that than $16,000 let alone $25,000 for another engine. I’ve heard varied opinions of what this might be, everything from rod knock to timing chain to valve tap. Considering the extent and type of damage will affect the engines candidacy for a rebuild (as I’m told), and that money is tight for me now, I’d much rather assess the damage myself as much as possible so as to avoid spending a few hundred on a shop taking my engine apart only to find it’s a totally unfixable dud.
I have a borescope and will be putting it into the cylinders to see if there’s any scoring. Is there anything else I should give a try for diagnostics so I can try to get an accurate picture of the state of the engine to describe to mechanics or rebuilders?
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in case it aids in anyone’s guesswork diagnosis. I also attached the work order from the shop if anyone wants to see the technicians notes.