[CININ]

Hey Guys I’m going to be taking a look at a 2009 335i e93, and I am aware of the n54 having some issues. Do any of you more experienced with the n54/e9X have some pointers of what I should look out and how I should look out for it. I have checked yt and other articles and I haven’t found anything directly showing me how to check for my self. Thanks merry Christmas

[dmckmc]

https://blog.fcpeuro.com/the-definit...bmw-n54-engine

[iqraceworks]

Lots, and lots of things to look out for. Search google, and read everything you can find.

Just remember, anything with an N54 in it is something that's going to require lots of maintenance, and TLC in order to keep it running right. And even then they will give you issues.

Get a good code scanner, and learn how to use it. MHD is great if you want to boost the power, and also take logs (it really helps with troubleshooting).

These are more fun/weekend/play cars...not "this is my only mode of transportation" type. Just way too many little things to go wrong and leave you stranded. If you don't have a reliable daily drive, DON't get a 335i.

[oVeRdOsE.]

step 1 done, you go on forums and ask .

Step 2 : are you willing to do some DIY, waiting for parts and get your hand dirty ? If yes, N54 is not ''that'' bad.

I see a lot of n54 to sell, stock, high mileage, all recalls done, maintenance done, from older people and it was their daily.

this article is pretty good : https://bmwtuning.co/bmw-n54-faq/


One main positive point, these engines are not rare, tons of info, tons of DIY, tons of parts. Also, one of the best ''potential'' hp VS $ ratio on the market.

It's a good engine for something like '' oh nooo, it's broken. Anyway. Upgrade time !''

Only the injectors really pissed me off. BMW know those are problematic, and it's very expensive ! Not rare to see a set of 6 new injectors equal or higher than the car value.


Also, there's a debate about N55 VS N54 reliability. N55 is a bit more reliable, and mine got 160k km, only basic maintenance done, nothing replaced or new on the engine (yet), not even carbon clean. Still running great.

[C4maro]

Originally Posted by iqraceworks

Lots, and lots of things to look out for. Search google, and read everything you can find.

Just remember, anything with an N54 in it is something that's going to require lots of maintenance, and TLC in order to keep it running right. And even then they will give you issues.

Get a good code scanner, and learn how to use it. MHD is great if you want to boost the power, and also take logs (it really helps with troubleshooting).

These are more fun/weekend/play cars...not "this is my only mode of transportation" type. Just way too many little things to go wrong and leave you stranded. If you don't have a reliable daily drive, DON't get a 335i.

I know that's true with tuned cars but is it as accurate about stock n54s? I bought mine at 135kms and now at 195kms and all I've done besides normal maintenance was the water pump.

[335i54n]

the problem is bmw and specifically the e90 has a Ton of common issues and reoccurring repairs, add to that the n54 turbo and injectors doesnt take much to mechanically total the car. stock will buy you more time but they are wear items.

literally everything will need to be replaced eventually, its insane

[Jaronbwall]

I hope he checked back to this post before looking at the car!! haha. So many minor issues you can check for with a bright flashlight and a little knowledge.

[AWD Addict]

Originally Posted by iqraceworks

Lots, and lots of things to look out for. Search google, and read everything you can find.

Just remember, anything with an N54 in it is something that's going to require lots of maintenance, and TLC in order to keep it running right. And even then they will give you issues.

It's not that bad. You're just recently scorned.

It's a fun enthusiast platform. I daily drive a tuned 08 w 140k on it. Definitely has it's regular issues, but if you pay attention to regular maintenance and spend a little money on it, it's a lot cheaper to own than anything new and a lot of fun.

[iqraceworks]

Originally Posted by AWD Addict

It's not that bad. You're just recently scorned.

It's a fun enthusiast platform. I daily drive a tuned 08 w 140k on it. Definitely has it's regular issues, but if you pay attention to regular maintenance and spend a little money on it, it's a lot cheaper to own than anything new and a lot of fun.

Yeah…maybe so!

But you have to admit that these cars (335i’s with the N54) have all kinds of issues that can, and will pop up given enough time. Turbo seals leaking, wastegate rattling, Injectors, LPFP, HPFP, knock sensors, fuel pressure sensors, vanos solenoids, boost solenoids, ignition coils, oil pan leaks, valve cover leaks, OFHG leaks……..those are all things that most 335i owners had issues with.

And then you get to the transmission (if it’s a 6AT) and you have your own set of issues. Seals leaking, shift solenoid acting up, E-clutch issues, etc. Several of those things will put the car into limp mode if the DME senses an issue……better have a scanner on hand to reset the faults if you need to make it to school or work.

Don’t get me wrong, these are awesome cars when they are running right…….but I’ve never had any type of car that has so many things that were prone to failing, or just acting up. They are definitely cars for "car guys"...people who like to tinker, and mess with things.

I think you could fart in the seat, and a 335i would go into limp mode.

[oVeRdOsE.]

N54 issue are somewhat comparable to most sport car in the same 'fun' range factor.

You'll have issue with the S4/RS4, C43, M3, RS3/S3, golf R, sti/wrx, 350/370, anything mazda speed, 90's JDM, etc.

often power comes with more complicated engines, more forces, thus less reliable.

Even a n/a porsche has few expensive issues.

Probably LS/LT/coyote engine are the most reliable for the power, but its a v8.

At least, N54 is not known for catastrophic failure, like the chains on the 4.2 and 3.0t s4.

Originally Posted by 335i54n

the problem is bmw and specifically the e90 has a Ton of common issues and reoccurring repairs, add to that the n54 turbo and injectors doesnt take much to mechanically total the car. stock will buy you more time but they are wear items.

literally everything will need to be replaced eventually, its insane

yeah its sad, almost like a disposable car. The issue here is some item need to be replaced often. When you think you sorted out the N54 for a while, some other item are waiting to fail AGAIN because there's no better aftermarket : seals, water pump, waste gate, fuel pressure sensor, etc...

[Bigtimekegger]

I have a 2008 BMW 335i. Almost 500,000km on it

I had COBB tune until about 400,000kms and then decided to de-tune it. I drove it hard, but also know how to properly warm up, cool down and care for a turbo car.

She will last if you take care of her.

View post on imgur.com

[AWD Addict]

Originally Posted by iqraceworks

Yeah…maybe so!

But you have to admit that these cars (335i’s with the N54) have all kinds of issues that can, and will pop up given enough time. Turbo seals leaking, wastegate rattling, Injectors, LPFP, HPFP, knock sensors, fuel pressure sensors, vanos solenoids, boost solenoids, ignition coils, oil pan leaks, valve cover leaks, OFHG leaks……..those are all things that most 335i owners had issues with.

And then you get to the transmission (if it’s a 6AT) and you have your own set of issues. Seals leaking, shift solenoid acting up, E-clutch issues, etc. Several of those things will put the car into limp mode if the DME senses an issue……better have a scanner on hand to reset the faults if you need to make it to school or work.

Don’t get me wrong, these are awesome cars when they are running right…….but I’ve never had any type of car that has so many things that were prone to failing, or just acting up. They are definitely cars for "car guys"...people who like to tinker, and mess with things.

Well, I'm a 3 pedal guy. So the AT isn't an issue (and I'd recommend to anyone to not buy one older than 2016 vintage.)

But candidly, I've had few of those issues. Those are all things that certainly could go wrong, but they're not all going to go wrong on every car, even a 15+ year old platform like this one.

I stand by my statement. I pay way less in annualized maintenance costs on this than a car of similar power and nature that's brand new. Is she bitchy? Yea, it's no civic. But splitting off the self-inflicted stuff, it's not that bad. It's not RX-7.

And in the end, the engine itself is an absolute beast. Many of us are running close to 2x the power without any major (internal) upgrades.

I think you could fart in the seat, and a 335i would go into limp mode.

[oVeRdOsE.]

Originally Posted by Bigtimekegger

I have a 2008 BMW 335i. Almost 500,000km on it

I had COBB tune until about 400,000kms and then decided to de-tune it. I drove it hard, but also know how to properly warm up, cool down and care for a turbo car.

She will last if you take care of her.

wow ! congrats.

This is something I always forgot to mention, but this is right. Most engine don't like quick heat cycle. Plastics and different metal alloy dont have the same thermal mass, thus not the same deformation speed.

now give us your maintenance list.

[zero2sixtyZ]

Originally Posted by iqraceworks

I think you could fart in the seat, and a 335i would go into limp mode.

[C4maro]

Originally Posted by Bigtimekegger

I have a 2008 BMW 335i. Almost 500,000km on it

I had COBB tune until about 400,000kms and then decided to de-tune it. I drove it hard, but also know how to properly warm up, cool down and care for a turbo car.

She will last if you take care of her.

View post on imgur.com

Did you do 15k mile oil changes?

[iqraceworks]

Originally Posted by Bigtimekegger

I have a 2008 BMW 335i. Almost 500,000km on it

I had COBB tune until about 400,000kms and then decided to de-tune it. I drove it hard, but also know how to properly warm up, cool down and care for a turbo car.

She will last if you take care of her.

View post on imgur.com

Exactly....but "take care of her" means throwing cash at her like a stripper

[lowrydr310]

Originally Posted by Bigtimekegger

She will last if you take care of her.

I picked up a 07 E93 335i last year with 160k miles on it. The car is completely stock. The common failure items have all been addressed by the previous owner. Oil pan gasket is bone dry which tells me that was replaced recently. Turbos, one bank of injectors, and HPFP were all replaced under warranty around the 90K mile mark. I think these are the big three high cost tems that distinguish N54 ownership from N52. The car was not tuned and used primarily to commute 35 miles a day.

OFHG was leaking so I replaced that along with the mickey mouse flange, new radiator, upper radiator hose, and a few other miscellaneous parts. There's a slight leak from the back corner of the valve cover - undecided on whether I should just do the gasket or replace the entire cover. I'm not sure about the water pump and thermostat but the rest of the cooling hoses look original and I need to replace most of them as they don't look healthy; planning on replacing WP and tstat at the same time.

I replaced two of my Index 9 injectors due to loud ticking and very mild symptoms of leaking. The front bank are still the original index 1 injectors, and now that the obnoxious ticking index 9 has been replaced I can hear one of the index 1 injectors ticking slightly. Also seeing a pretty big difference between the fuel trims between bank 1 and bank 2, so either my index 1s are flowing too much or my index 12s are restricted and/or flowing too little.

Sorry for the rant. My point is that the N54 E90 can last long, and aside from HPFP, Turbos, and injectors, it's not that much different than maintaining an N52.

[Bigtimekegger]

Originally Posted by C4maro

Did you do 15k mile oil changes?

Oil changes every 10,000km.

[Bigtimekegger]

Originally Posted by iqraceworks

Exactly....but "take care of her" means throwing cash at her like a stripper

Interior still looks and functions as new. Water pump I have gone through 4 of them (seems to be the Achilles heal).

Changes batteries a couple times, injectors once, alternator once, serpentine belt once, carbon cleaning twice, ect. Engine and manual transmission still runs strong and shifts seamlessly (changed transmission fluid 3 times and rear diff fluid 3 times), sensors as they fail I will replace.

Over the course of my ownership, if I break it down on a per-year cost, it has been VERY manageable.

[oVeRdOsE.]

Originally Posted by Bigtimekegger

Interior still looks and functions as new. Water pump I have gone through 4 of them (seems to be the Achilles heal).

Changes batteries a couple times, injectors once, alternator once, serpentine belt once, carbon cleaning twice, ect. Engine and manual transmission still runs strong and shifts seamlessly (changed transmission fluid 3 times and rear diff fluid 3 times), sensors as they fail I will replace.

Over the course of my ownership, if I break it down on a per-year cost, it has been VERY manageable.

thank you to give us hope

it's 50/50 online, some says they are great and reliable engines, some are hating them. At the end not everybody got the same definition of ''reliable'', for some a simple early coil replacement, and this engine is shit....

I know n52 running cooler, but my water pump got 270k km on it, OEM, and I've changed it on preventive maintenance, because I planned a 6h trip.
So it technically still running.

And my N54, Ill run low boost tune + 50/50 meth-water injection, on a ''all maintenance done'' n54 engine. Hopefully it will last for a while.
I'm doing around 4000km/year, so 10years+ before major maintenance.

[Bigtimekegger]

Originally Posted by oVeRdOsE.

thank you to give us hope

it's 50/50 online, some says they are great and reliable engines, some are hating them. At the end not everybody got the same definition of ''reliable'', for some a simple early coil replacement, and this engine is shit....

I know n52 running cooler, but my water pump got 270k km on it, OEM, and I've changed it on preventive maintenance, because I planned a 6h trip.
So it technically still running.

And my N54, Ill run low boost tune + 50/50 meth-water injection, on a ''all maintenance done'' n54 engine. Hopefully it will last for a while.
I'm doing around 4000km/year, so 10years+ before major maintenance.

Ya I mean coils, plugs, injectors, ect. those in my opinion shouldn't even be a consideration. Those 100% will need to be replaced, but that's the same on any car and even more frequently if your running a tuned car.

I really cannot complain at all with the solid engine and transmission. I am still on my original clutch and flywheel (never changed). I'm sure the HPFP will be needing replacement in the near future, but as of now, no codes and still going strong. How that has made it to almost 500,000km.

I know there are certain BMW engines that have issues, but the N54 in my opinion is def not one of them. If you can take an engine that makes 300HP OEM and boost and mod it to 500-600HP or more and the internals on the engine hold up no problem - you have a solid engine.

[AWD Addict]

Originally Posted by iqraceworks

Yeah…maybe so!

But you have to admit that these cars (335i’s with the N54) have all kinds of issues that can, and will pop up given enough time. Turbo seals leaking, wastegate rattling, Injectors, LPFP, HPFP, knock sensors, fuel pressure sensors, vanos solenoids, boost solenoids, ignition coils, oil pan leaks, valve cover leaks, OFHG leaks……..those are all things that most 335i owners had issues with.

And then you get to the transmission (if it’s a 6AT) and you have your own set of issues. Seals leaking, shift solenoid acting up, E-clutch issues, etc. Several of those things will put the car into limp mode if the DME senses an issue……better have a scanner on hand to reset the faults if you need to make it to school or work.

Don’t get me wrong, these are awesome cars when they are running right…….but I’ve never had any type of car that has so many things that were prone to failing, or just acting up. They are definitely cars for "car guys"...people who like to tinker, and mess with things.

I think you could fart in the seat, and a 335i would go into limp mode.

My thermostat CEL is tripped.