[evanmiller]

Hi,
I have a 2011 320i LCI (originally from Singapore but now imported to Ireland)

The engine is suffering failing bottom end bearings and is currently parked up.

I’m desperately searching for a replacement engine but to no avail as my engine code is N46B20BD.

It seems all of the engines with this exact code are located on the east side of the world : Russia , Kazakhstan, Japan.

However there is plenty of N46B20BA engines available near me in the UK.

Can someone tell me if these engines are cross compatible?

Many thanks

[Psalm_Kuru]

Hey! Sorry this is completely off topic from what you've asked, but what are the symptoms of bottomed end failure? What's the mileage on the engine? You aware of what the causes could have been? I'm new to this type of engine so wanna make sure I can do whatever to avoid this type of damage, apologies I'm not able to help answer your question but I do believe the N46B20-BD is direct injected where as the other one isn't? I'm not 100% sure?

[evanmiller]

Originally Posted by Psalm_Kuru

Psalm_Kuru
Hey, how are you?

So firstly my car/engine is at 84,000km.

A serious engine failure like this for such a young engine is rare but not unheard of if correct maintenance isn’t performed.

Firstly the cause of this failure was most likely the previous owner not correctly servicing the car at the right intervals and running the car with low oil levels.

This lack of servicing caused the timing chain guides to become dried up and prematurely fail, this then caused an avalanche effect with the broken down debris from the failed guides falling into the oil recirc pump which is responsible for feeding the bottom end.

With the bottom end slowly becoming starved of oil over time it wasn’t long before the engine was done for , by the time I heard the tell tale symptoms of “rod-knock” or failed bottom end bearings the damage was done.

This can be confirmed by obviously the horrible RPM related knocking and pulling the oil filer out and inspecting for copper flake deposits (signs of broken down bearings).

Unfortunately with me being based In Ireland and this specific engine coming from eastern territories it leaves me In the uncomfortable position where I have to try and source a rare donor engine or scrap it for what it’s worth.

If you have only just acquired your car and not confident in the previous service history I would firstly recommend bringing it to a decent mechanic (who knows BMW’s). I would ask them to perform a thorough inspection of engine components and do a chain and guide replacement - it’s just worth it. If I had done that at the beginning of my ownership I would be in a different position now and not down thousands of euro.

Following that just keep it topped up on fluids and service it on time. Also if it’s electronic oil measurement (no dipstick) be very wary that it doesn’t run low as Ive heard they can become less accurate over time and especially with BMW petrol engines being high consumers of oil.

Best of luck my friend.

Evan

[Psalm_Kuru]

Awesome Thanks for the very detailed reply, Yes that does seem like pretty low Kms for that amount of damage but considering its past it would seem understandable.

Mines got around 120,000kms about 30,000km being me and the rest being my grandmother's she was pretty good with maintenance I haven't replaced the chain/guides 'Yet' but will look into it, pricing for repairs in New Zealand are pretty costly/Up there.

I've had a couple troubles with those electronic oil level sensors myself. Specially on long distance travel it drops below min/ red section, which is pretty scary for myself personally. But I leave it to sit for about 2-3 hours and seems to be full again? Would you trust that or maybe look into a replacement sensor maybe?

Thanks again, Psalm