May 13, 2023 · I think the n55 is a very reliable engine. I’ve owned a 2011 335i MSport for 3 years, and it’s been a very reliable car. My wife previously owned the X3 35i with the n55. She owned that for 5 years and that was also very reliable. We both replaced valve cover gaskets. But aside from that, all has been well. Reply reply Robodinox •

Apr 27, 2023 · My car is an F30 2013 BMW 335i, N55 8 speed. A little over a year ago this issue started. Driving home from work and I got a check engine light. Read the code with MHD, said my thermostat was clamped open. So I purchased a new thermostat from fcp euro and replaced it.

Aug 29, 2015 · Bmw tech perspective here. The N55 is a better more reliable engine than the N54 was. Actually issues with the n55 are fairly few. On occasion I have had to do the valvetronic motor, thermostat, and boost control solenoid. Cracked vacuum lines can cause low boost faults too. Oil leaks from the common areas include the oil filter housing and occasional oil pan gasket. Other things to consider ...

Apr 22, 2022 · A n55 is a lot better for a daily for the more reliable injectors alone. N55 even with a bigger turbo is only just as capable of a fully bolt on n54 (e30, 20psi, inlets, etc) with original turbos.

Nov 19, 2014 · Awesome! Yes everyone tells me to tune my 335i but from what I researched online the n54 responds better to tunes and I haven't been able to find a good review of someone with the n55. Cobb claims 18% HP and 26% TQ increase on there stage 1 aggressive setting, but don't know if thats okay to leave it on aggressive all the time. Also is it okay to drive on aggressive with California 91 octane fuel?

Oct 25, 2022 · Took me a weekend working slowly on my N54 car. Most harrowing part for me was cleaning up the old gasket material. I was really nervous about dropping something in. Def buy the cover from FCP, I think that warranty might come in handy on it. When doing the VCG on an N55 do you need to worry about priming the system like you do with the OFG?

Jul 27, 2021 · If I go fbo stage 2 on an n55, how much hp will i make? Ik the n54 can make about 500 but I heard the n55 isn’t as tuner friendly. Is that true

Aug 19, 2020 · The 335i N54 is the better platform for high power than the N55, but putting the right materials to keep it reliable at that power is a must.

Feb 1, 2023 · I always used mobil 1 0w40 on my n55 and n54. Decided to try Castrol 5w40 recently on the n54 and notice more engine noise on cold starts so I'll be switching back next change.

Mar 9, 2023 · I had a 335i F30 from 70k miles to 105k miles and my issues were high oil consumption (with no actual diagnosable issue) and I had a few coolant hoses crack that left me stranded. So yeah if you were to get a high mileage N55, I would replace ALL of the coolant hoses as well as the expansion tank on like day 1, along with the chargepipe.