N55/B58 m235i or m240i purchasing advise

[Ollic]

Hey all, after some advice, currently have an e92 335i with an n54, that’s proven to be, less than reliable in my 18 months of ownership.

Recently the biggest issue was the con rod bearings spun, so a replacement motor has been fitted, I’ve had turbos rattle, vanos solenoids fail, water pump failure, injectors, hpfp, basically every major component that could go wrong, has, even the damm E clutch in the gearbox.

So, now it’s fixed for the time being, I’ve decided to upgrade to a newer platform with less mileage and hopefully more reliable, leaving me with 2 or 3 options.

M235i-approx £17k-2016

M240i- approx £22k-2016

435i-approx £20k-2015

Car will be used daily, want an auto, and like the looks of both the 2 and 4 series, buying the 235i would give me an extra 4-5k to put towards mods for FBO.

My only concerns are, the n55 bearing failure that seems prevalent, and valvetronic failure, I do everything DIY and have for 15 years, but it’s still a rather large issue by sounds of it, and want to avoid a dead motor like my n54, also seems like it has the same issues such as OFHG leak causing belts to be injested etc.

B58, seems reliable, only concern is how are they to work on compared to an n54/55, and obviously chain/vanos is at back of the engine.

Any advice and experiences welcome.

[MarcoZandrini]

Get the B58. It’s a beast.

[Beach Boy]

I have been pleased with the 2016 435i that I bought earlier this year. It was in a deceased estate and had only 12,000 kms (7.5k miles) and a full, by date, service record. I use it most days and it is a joy to drive as it has the full M-Sport package and really goes well, when requested.

[tac911t]

Get the B58. It’s a beast.

I agree, have had my M240i for just over a month. Great car, and now that I have tweaked the settings using E-sys to my preferences, it is even better.
You can't worry about the effort to repair/work on any modern ICE, they are all difficult, due to the packaging of the engine in the compartment, the amount of emission controls (sensor, hoses, wiring), which makes
even maintenance items difficult.

Search in YouTube for videos on the N55 and B58 motors, to see the maintenance differences and the benefits of the B58 packaging (more items moved away from the hot exhaust), and using insulation to help
the plastic parts retain heat, to reduce the effects of becoming brittle over time.
My comment about repairs being difficult, is in reference to a video I watched on how to replace the valve cover gasket on the B58. There is a lot of items to remove, including the fuel rail, which requires finesse and
time (especially if you don't have the tool).