[DocMike86]

I have a stock ‘13 335is with the N54, 34k. I’ve owned it for 2 years, track it 3 times a year. Only upgrade is the charge pipe. While the heads are off for walnut blasting, are there any mods that will serve to harden the engine, ie. plastic parts, etc. that anyone might recommend?

[Dave92N54]

I mean with the intake off it's a lot easier to do the oil filter housing gasket, the low pressure fuel sensor, and crank position sensor. That's all I can really think of. I mean if you want to spend the money I guess you could go to a metal intake manifold but christ the stock one is usually good for 30psi+.

[Jklad]

Maybe replace all your vacuum lines on the filter side if you havnt ever done it, and a rb pcv.

[DocMike86]

Exactly the advice I’m looking for. Thanks.

[PS2N54]

with manifold off, there is a ground wire near steering column, should consider changing, it grounds the starter. mine corroded on a N52 and it was the only time the car ever left me stranded (no crank). there is another ground wire on opposite side of engine too if you want to change that too at same time. i just custom made some jacked 4 or 6awg wires instead of replacing with the same exposed copper ribbons from oem. very cheap and easy to do if incase your ground wires show signs of corrosion.

[335i54n]

with that mileage, nothing. intake is super ez removal anyways