I am thinking of buying a 2012 series 1 convertible 120d but come across lots of negative posts on the 4 cylinder n47 engine with the timing chain failure. Can anyone help me work out if the year I am thinking about buying is in this bracket! It’s done 40000 miles. Can’t see any recall on the MOT check. 
Engine code N47D20O0

I don’t need a headache or the cost.

Any feedback would be great.

Hi Lorraine,

Frankly, I wouldn't bother. Plenty more cars out there:

https://www.google.com/search?client=firefox-b-d&q=N47D20O0+problems

 

Morning Lorraine

The N47 4 cylinder Diesel engine was in production and use by BMW from March 2007 up till September 2014. I have no personal experience of owning a vehicle with this engine but have helped a friend of our sons with an engine change in his 120d, he brought a second hand unit from a specialist BMW breaker. As an Engineer I just had to look inside once the scrap engine was on the floor, my assessment is first the tensioner begins to fail allowing slap and accelerated wear of guides and chain. Sadly due to the design of the engine the drive sprocket on the crank also seems to wear but "usefully" is welded to the crankshaft!!! So to repair these it would in my opinion also need a new crank to do it properly. Not the engine designers finest effort or BMW's who it seems initially just put their heads in the sand and ignored the issue, it seems they took a view that number of failures against number of units sold meant the issue was a customer one not theirs?? The difficulty is some engines have reached astronomical mileages without issue while others have failed early with full service history's. 

As Richard says walk away or look at a petrol model, if a Diesel is your preference make sure you have evidence of a good history and a solid either BMW AUC Warranty (I would make an extended AUC warranty part of the deal) or good aftermarket Warranty just in case.

Dave