[BMWSource]

Hello all N55 owners, I currently own an 2006 E90 N52 330Xi Sedan, I am currently looking at the used car market for N55 335i’s 435i or 535i models. I have a question about N55 reliability? Is the N55 more reliable than the N54? My current E90 is almost 20 years old, & I’m the 3rd owner, the 2nd owner didn’t look after the car properly long story short, & I have owned my N52 for 6 years, but now I am thinking about getting an N55 BMW from 2012-2015 for the 335i/435i & F10 2011-2016 I need your answers, advice on someone like myself getting into an N55 engine. I know it’s turbocharged & I need to look out for rod bearings, walnut blasting, HPFP etc, but I spoke to a lot of N55 owners & told me that it’s not unreliable like its predecessor the N54. What should I look when buying my first N55 BMW?

Thanks

Your advice is greatly appreciated

[F32Fleet]

Originally Posted by BMWSource

Hello all N55 owners, I currently own an 2006 E90 N52 330Xi Sedan, I am currently looking at the used car market for N55 335i’s 435i or 535i models. I have a question about N55 reliability? Is the N55 more reliable than the N54? My current E90 is almost 20 years old, & I’m the 3rd owner, the 2nd owner didn’t look after the car properly long story short, & I have owned my N52 for 6 years, but now I am thinking about getting an N55 BMW from 2012-2015 for the 335i/435i & F10 2011-2016 I need your answers, advice on someone like myself getting into an N55 engine. I know it’s turbocharged & I need to look out for rod bearings, walnut blasting, HPFP etc, but I spoke to a lot of N55 owners & told me that it’s not unreliable like its predecessor the N54. What should I look when buying my first N55 BMW?

Thanks

Your advice is greatly appreciated

EWG (2014+) units have revised bearings. Typically better. The problem will always be the prior owner maintenance and how the car was driven.

[thatgarrett]

Yeah I didn’t know the PWG or EWG difference- not a huge difference but the turbo has more headroom for tuning and you don’t have to deal with little things like the boost solenoid failing on the PWG. I wouldn’t let it stop me from getting a well sorted PWG N55- that would be pretty far down the list of other factors (options, packages, color, mainlanders history) though

N55 is one of the more reliable engines of this era of BMW, huge step up from the N54 and much better than the N20/N26. Most of the common problems would be the same as your NA i6 tbh- VCG, OPG, OFHG, Mickey Mouse coolant flange- none of that is really turbo specific. Charge pipe is probably the only common failure point that is turbo specific but is cheap and not hard to DIY. Stock boost stays below 8 psi for the most part so these engines aren’t run that hard either

[Timevampire]

Yes it's more reliable. Improved vanos decreases intake valve cleaning interval. Also the change in injector design.

Only issues I have had: burst charge pipe. Broken coolant line (by hand accidentally)

[n55david]

Stay away from any pwg car.. simple.

[VanillaBimmer]

From the information I have gathered this idea that PWG have different rod bearings than EWG is nothing more than a myth. Until someone brings evidence to the contrary I would not buy into it. As far as reliability it might depend on your definition of reliable, your mileage may vary. I have taken amazing care of my car and have detailed mechanic documentation for its entire lifespan, however, over the last year it just keeps running into issues. And whenever you do go to fix anything on this car yourself be prepared for an engine designed to be annoying to work on lol. Extremely annoying and costly and it seems like it needs constant maintenance. Some people may not run into that many issues if they are lucky. But I would not go into a car like the N55 thinking it is some massive improvement from the N54 in reliability. More reliable most likely, but there are other issues popping up with the rod bearings that I did not see on the N54.

Honestly, if you haven't driven the N55 I may suggest giving it a test drive as the change in steering may not even be something you are interested in as it marked a big shift in design/feel. If you love the car and accept it is on average not cheap to own, then go for it.

[wheela]

Originally Posted by VanillaBimmer

From the information I have gathered this idea that PWG have different rod bearings than EWG is nothing more than a myth. Until someone brings evidence to the contrary I would not buy into it.

I agree with rod bearings. It appears it goes more by year. I have a 2015 X1 n55 with pneumatic wastegate, and realoem shows that my rod bearings (and rods, for that matter) are also used on s55. Here's what realoem shows for my rod bearings. Looks like 2005 - 2011 were original, then another bearing for 2011 - 2012, and then a 3rd for 2012 - 2018 (including s55).

[wheela]

Originally Posted by VanillaBimmer

Some people may not run into that many issues if they are lucky. But I would not go into a car like the N55 thinking it is some massive improvement from the N54 in reliability. More reliable most likely, but there are other issues popping up with the rod bearings that I did not see on the N54.

Honestly, if you haven't driven the N55 I may suggest giving it a test drive as the change in steering may not even be something you are interested in as it marked a big shift in design/feel. If you love the car and accept it is on average not cheap to own, then go for it.

Alot of issues will be common between n54 and n55, but some key areas where n55 is better than n54 regarding reliability are:
-fuel injectors
-fuel pump (except for early n55's)
-carbon build-up on intake valves
-DME (mosfets go bad on MSD80, but MSD81 is okay)
-vanos (n55 got improved vanos system)
-single turbo (2 turbos = 2x liklihood of turbo or boost solenoid related issues)

I think the only thing n55 suffers from that n54 doesn't is valvetronic issues, since n54 doesn't have vanos).

[scubajim]

I have 2, a 2015 535 F10 and 2016 435 F33. Have owned the 535 for 4 years and the 435 for 2. Other than regular maintenance, the 535 had a valve cover leak. Both cars have been very reliable. I agree with the others that regular maintenance from the previous owner should be the difference maker.

[cfm56d7b]

Originally Posted by scubajim

I have 2, a 2015 535 F10 and 2016 435 F33. Have owned the 535 for 4 years and the 435 for 2. Other than regular maintenance, the 535 had a valve cover leak. Both cars have been very reliable. I agree with the others that regular maintenance from the previous owner should be the difference maker.

Could not echo the comment about verifiable maintenance history in any other manner. It's a must.

If you have the option, perform oil analysis prior to purchasing the car. In 2013 model year, a small percentage of N55 engines experienced a rare issue with premature rod bearing wear. Oil analysis will confirm it.

If you do purchase the car, replace the charge pipe with a metal one.

[SlumsToMills]

Originally Posted by cfm56d7b

Could not echo the comment about verifiable maintenance history in any other manner. It's a must.

If you have the option, perform oil analysis prior to purchasing the car. In 2013 model year, a small percentage of N55 engines experienced a rare issue with premature rod bearing wear. Oil analysis will confirm it.

If you do purchase the car, replace the charge pipe with a metal one.

I have a 2013 F30 N55 335i with 82k miles. What rare issue pertaining to premature rod bearing are you talking about? I have done oil analysis for the last 6 oil changes and nothing stands out but maybe I dont know what to look for?

What am I looking for in the oil analysis that would indicate rod bearing wear or failure is close?

Thanks, much appreciated.