N55's...how reliable?


Nov 5, 2016
Hello people of SS. I just recently sold my N54 335i and was looking into the N55's due to so many issues that the N54's had. I N54's are known for wastegate rattle, vanos solenoids, cam ledge issues, HPFP, etc, etc...but I'm wondering how much more reliable and/or improved is the N55 engine over the N54.

What are some issues that you guys have experienced and at how many miles?
Any certain bits of knowledge/information one should keep an eye out when shopping for an N55?

Thanks in advance!

[edit:] Oh, and I'm genuinely interested in this; not posting for points/troll purposes


Nov 5, 2016
London Ontario, Canada
From what I have seen, the issues are less common but more expensive (or a bigger deal in general). Main bearing failures as well as camshafts journals/bearings failing on the intake camshaft. The valvetronic system doesn't seem to be very problematic, but when an issues arises it is also expensive to fix.
The failure's in the n54 seem to have been rectified with the n55, (for the most part, they can still fault on an n55) but are far less common.
There is as well pcv system issues on the n55, sometimes get a whistling noise coming from the front or rear main seals, as the crank case pressures become out of whack.

As I said, less common more expensive.
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Nov 5, 2016
San Antonio, Texas
2011 335i with 70k+ here, no problems (knocks on wood). But it has been meticulously maintained and is only slightly modded (for now). I am planning for the water pump to fail and fuel pump issues. But compared to my RX-8 this thing is a Civic.

But i did a lot of homework and found that everyone who owned and N54 car and then a N55 car, said that the N55 was far more reliable. I saw no reason to take a risk on a N54 since I don't plan on making more than 450WHP.


Nov 5, 2016
Gilbert, AZ
I have a 2013 535i, I bought it at 45k miles, now at 56k miles, I had the LPFP go bad and replaced by dealer under warranty. I did recently change out spark plugs and Walnut blasted Intake valves.
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Nov 17, 2016
2014 335 N55 (23xxx miles) with 0 mechanical issues whatsoever. outside of PPK I've left it stock since it's the daily. But ive been pleased on that front; outside of basic upkeep under warranty it's been solid.
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Nov 5, 2016
73k miles just started to have issues after not a single issue besides rack and pinion which is kind of common for e92s. Water pump and wastegate actuator sensor failed coolant res also.


New Member
Nov 5, 2016
Milwaukee, Wisconsin
I'm at 79k and I've only really had the common issues. Luckily I'm under CPO until 100k. I've had the water pump, oil filter housing gasket, and valve cover gasket replaced. Less common issues would be the rear tail light and wheel speed sensor. I'm pretty happy with how reliable it has been so far, but I also take pretty good care of it and I'm only running the PPK.


Dec 1, 2016
New York
N55 remedied a few of the big issues that the n54 had. Injectors are a new design, the hpfp is the same but is at least a later revision part number, the oil pickup was redesigned to reduce starvation issues and frothing, blowby ports were added to the head to prevent carbon accumulation on the valves, and coolant passages were revised to have greater control over cylinder head temperature and keep important things like the injectors cool.

The bad is still the water pump failures on 2011s and early 2012s. I think the "v2" water pump part number came out in 2012. Expect a water pump failure as early as 60k miles. Mine failed at 75k. The pcv system is also prone to failure and very expensive to fix due to being integrated into the valve cover. Another common issue is the charge pipe blowing off the throttle body. Vanos bolt's breaking were also an issue, but effected vehicles should all be recalled and repaired by now...
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Nov 14, 2016
North Wilkesboro
At the end of the day... you need to decide for yourself if it's worth it.

Before buying anything substantial you need to add up all the 'what if' factors and decide if it's worth it to you.

N54s will have problems, N55s will have problems, Every Engine will have problems.

The systems aren't perfect and never fully will be.

If it were up to me,
I'd look at the possibilities such as, Upgrades, Capabilities, and aftermarket.

If you're going to keep it bone stock then just look over some reviews and see whats going wrong.
If you're going to beef it up and make a monster. See what all is out there and, what all is known.


Nov 1, 2016
My waterpump went out at 42k -- crazy since my n52 is still on the OEM waterpump at 85k miles. thats the only major thing thats happened so far though
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