[CambsCreative]

I'm, potentially, looking to buy a used BMW 3 series, the post 2016 Facelift LCI version but wanted to check a few things with you guys.

I am aware (as most on here will be) of the timing chain tensioner issues of the pre LCI 3 series that used the (I'm talking petrol engines here) N20 engine, an engine that also suffered numerous other issues that I won't list. The LCI version used a B48 engine that, from what I understand, did not have the same timing change tensioner issues, is this correct?

Is the B48 petrol 2 litre engine generally reliable compared to the N20 and did the other reliability issues (oil leaks, water pump, shrapnel getting into the engine, etc) get ironed out with the B48 engine?

I have owned several BMWs over the years, be it older naturally aspirated petrol ones with high mileage and I was constantly in my local BMW independent garage having something or another sorted on them so, years later after owning Vauxhall, Audi etc I like the idea of an F30 3 series now that the used ones are within my budget, but want to make sure that B48 engine is a good one and does not have any known issues like timing chain tensioners, swirl flaps (diesel of course) type things that BMW have been known for in the past.

Course, I understand that every make and model car has issues, VW/Audi with oil leaks, timing chain issues, DSG gearboxes with mechatronic boxes breaking left, right and centre, Ford Echo engines packing up all the time, Mercedes electrical gremlins, Vauxhall, well, the list is endless there and I should know as I currently own a 1.6 naturally aspirated petrol Astra J and oil leaks seems to be the flavour with it this year, it's always going wrong.

I could of course by a Kia Xceed that would be reliable, never go wrong and would still have 4 years warranty left, but how boring would that be. It would not be an exciting drive, just a dull old A-to-B car, which I don't really want.

Thanks guys

[MidtownMike]

B48 does not suffer from structural chain guide issues like N20. However, as with all modern BMW engines, it does make extensive use of plastic parts, e.g. in the cooling system, which may need replacement with higher mileage cars, as they get brittle over time.
Best known structural problem on the B48 in the F30 is the coolant vent line between expansion tank and cylinder head. The connector on the cylinder head will get brittle and break, and will dump all coolant. BMW has revised the part 3 or 4 times. If it has not been replaced, you should replace it asap with the latest part number, or it WILL fail on you.

[CambsCreative]

Thanks Midtown, good to know about the coolant vent. Is that a big job and what would that cost me to have done?

Regarding cooling system plastic parts, what's the cost involved in parts/labour for that?