It's N14 engine rebuild time!
 

Soooo.... the $35 endocam confirms that not only is #4's #1 exhaust valve missing a chunk
but all four bores are scratched all to #waffles#.

This is in a 2009 (6-08 build date, go figure) JCW Clubperson (it's 2024, not 1964)
Pistons don't seem to be too hard to come by, valves aren't expensive, and until I pull it apart
I can't find any real evidence of either a warped head or oiling system failure.

So, making the crass assumption that I can 'fix' this N14 with a valve job,
injector cleaning/ replacement, HPFP R/R.
boring to 77.25 or 77.50 pistons, and the usual consumables*,

tell me your tales of what else goes into making an N14 a bit more
reliable, a bit lower maintenance, and as durable as it can be,
given that stock performance is just fine.

And it's only throwing misfire codes for #3 and 4. I'da thunk by this point it'd have a laundry list of codes...

Thanks!
t
*all the typical BMW plastic pipes, hoses, radiator, valve cover, etc.
https://cimg3.ibsrv.net/gimg/www.nor...cd8b3ec236.png
all four show this scoring under the injectors.
https://cimg1.ibsrv.net/gimg/www.nor...bee954e2a8.png
oh, hey- I wonder if the compressor wheel had anything to do with all these scratches.

My first question is always “How much longer do you see yourself owning the car?” Second question: “What do you hope to get out of the rebuild?” The answers to those two questions will help guide you in your rebuild path. And, there are many paths to take….

No MINI engine rebuilding experience but with other engines just a good rebuild using factory parts and maintaining factory fits/clearances/etc.

Proper rebore no larger than necessary. New pistons/rings to fit new bore diameter. New rod and main bearings. (Crank journals mic'd to check for excessive wear. None found. But used Plastigauge to confirm proper main and rod bearing clearances. Main and rod bolts and head bolts, etc., replaced as per factory. Valve job. New cam/cam sprocket, chain. New oil pump. New water pump. T-stat. Gaskets, seals, etc.

The result is an engine that is at least as durable was it was from the factory. Maintenance schedule remains unaffected. That is I still adhered to a reasonable oil/filter service -- given my vehicle usage every 5K miles -- and engine air filter, plugs, etc on factory schedule.

Forgot to mention but very important is a through cleaning of the bare block and head. And you must run something -- I used a rife cleaning kit -- through all oil passages to ensure they are free of any debris, sludge, whatever.

When rebuilding an engine cleanliness is critical.

Well said.
I snooped around on car-part, and quickly found that for what junkyards want for an engine, I can buy a 1st gen car in average condition...

So my answers:
1- at least 4 years at 10k a year. Ideally 8 years.
2- factory performance, even slightly derated if it'll last longer.

Rock, having been a BMW problem child for decades,
the absurd expense is always pistons.
Toyota pistons are $40 a pot. BMW is up to well over $200.
ECS sells aftermarket for $100, but...
Oh- there's always counterfeit Mahle off ePay from China!

Also, all the machinists I have used successfully in past are gone.

But yeah, there's no time or storage crunch on this one, so I'll probably pull it
and reassess once it's all apart. Make a big parts list, price it,
freak out, and see if I can find a machinist...

​​​​​​​thanks, both.
t