F12 640i/650i Convertible

[ReaperCushions]

Looking at pretty cheap second-hand deals on these for 2012-2014 petrol models, generally between 50k-80k miles.

Does anyone have any good / bad experiences with them?

My temptation is to avoid the 650i V8 due to various valve stem issues (Is that over blown?) but equally the N55B30 seems to have its own issues as well.

Other general thoughts / concerns on the F12 would be very welcome of course! Just trying to avoid any major engine issues that I have missed.

Thanks!

[ReaperCushions]

Quick bump!? I'm hoping to go and look at a few this weekend so would love some input!

[d_a_n1979]

ReaperCushions said:

Quick bump!? I'm hoping to go and look at a few this weekend so would love some input!

How; all car dealerships are shut aren't they?

[ReaperCushions]

d_a_n1979 said:

ReaperCushions said:

Quick bump!? I'm hoping to go and look at a few this weekend so would love some input!

How; all car dealerships are shut aren't they?

I'm in the USA, most have stayed open.

[naturalaspiration]

Hot vee V8s are the ones to avoid due to heat dissipation problem, I6s are much more reliable.

[ReaperCushions]

Thanks, that’s useful. The nicer ones on the market seem to be the 640is rather than the 650is anyway. For some reason most of the 650s have extra M badging and dubious tricolors added everywhere possible.

[Crackie]

ReaperCushions said:

Thanks, that’s useful. The nicer ones on the market seem to be the 640is rather than the 650is anyway. For some reason most of the 650s have extra M badging and dubious tricolors added everywhere possible.

I think all the 640i production had the same model N55B30 engine ( Same engine as used in the early M135i and 740i ) these had an uprated intercooler and radiator compared to the standard N55. They are rated at 315bhp but apparently make approx 335hp from the factory and 390 when mapped.

Later 'standard' N55s, from mid 2013 onwards, gained an electronic rather than a pneumatic type wastegate. They also received a slightly larger diameter turbo and larger diameter inlet and exhaust plumbing around the turbo. These late 'standard' N55s, used in the 435i for example, apparently make 395hp with just a stage 1 map.

[ReaperCushions]

Thanks, guys, appreciate the input. I must admit, I'm not much of a tuner, so unlikely to do that, but it's good to know the internals of the engine seem strong.


Anyone else got anything I need to keep my eye on?