[AntonySMith]

What are in your opinion the most reliable diesel and petrol engines of BMW F30?

[floydarogers]

Originally Posted by AntonySMith

What are in your opinion the most reliable diesel and petrol engines of BMW F30?

N55 and N26 in 320i form. Possibly N47, too, if the timing chain problems are fixed.

The newer B58/B48 engines don't have enough history.

[HighlandPete]

Originally Posted by floydarogers

N55 and N26 in 320i form. Possibly N47, too, if the timing chain problems are fixed.

The newer B58/B48 engines don't have enough history.

I'd say the N57 diesel is the most reliable engine from what we see in the UK. A few EGR cooler failures, but as it is an external ancillary component, not too big a deal.

It is a big 'if' for the N47. The used market will be very nervous of the N47 as mileage is added, due to the poor track record of N47 timing chain failures.

[TodmordenLad]

The 3 litre 6 cyl diesel in my own experience.
Have driven it in 3 cars, only totalling 100,000 miles admittedly. Not one engine fault - only issues I've had have been with TPMS and internal lighting, all fixed under warranty of course

[stormlv]

From a sample of one, my engine (N57) is quite reliable.
It has been tuned for the past 30k KM and I have no issues yet (knock on wood)

[STR8-6IX]

anything turbo in general will be less reliable than naturally aspirate counterparts. alot of long term reliability depends on how the car was driven for the first 3000 miles. if you refrain from revving past 3-4K for this period, the piston rings and what-not will seat properly and ensure you dont burn a drop of oil down the road. this ensures that your engine lasts as long as possible. although this has nothing to do with the f30, the most reliable engines BMW every built was any inline 6 in the e46 or earlier. these engines are alot easier to work on compared to the newer stuff as well. when the new age of BMW engines was introduced (N52+) lots of complex electronics were added. IMO, the most reliable modern BMW engine is probably the N52.

[Tommy_hf]

Just saw a 2013 535d for sale with 580000 km.. . 3 litre diesel gets my vote then.

[Michael Schott]

Originally Posted by 6IX-F10-N52

anything turbo in general will be less reliable than naturally aspirate counterparts. alot of long term reliability depends on how the car was driven for the first 3000 miles. if you refrain from revving past 3-4K for this period, the piston rings and what-not will seat properly and ensure you dont burn a drop of oil down the road. this ensures that your engine lasts as long as possible. although this has nothing to do with the f30, the most reliable engines BMW every built was any inline 6 in the e46 or earlier. these engines are alot easier to work on compared to the newer stuff as well. when the new age of BMW engines was introduced (N52+) lots of complex electronics were added. IMO, the most reliable modern BMW engine is probably the N52.

I disagree. First of all BMW recommends a 1200 mile break in period, not 3000 miles. Surely the parts will be well seated by then. Second, modern turbocharged engines are highly reliable. The proof is turbocharged diesel engines that routinely last 100's of 1000's of miles.

[Y0tsuya]

Originally Posted by 6IX-F10-N52

if you refrain from revving past 3-4K for this period, the piston rings and what-not will seat properly and ensure you dont burn a drop of oil down the road.

Yes they said try not to rev past 4K for first 1K or so miles. But that's pretty much impossible to do once I merge onto the autobahn.

[STR8-6IX]

Originally Posted by Y0tsuya

Yes they said try not to rev past 4K for first 1K or so miles. But that's pretty much impossible to do once I merge onto the autobahn.

you have an m235i, i have a 528i. be reasonable here!! haha

break-in procedure is NOT 1000miles for any car. engine is not fully sealed until 3000miles.

[STR8-6IX]

Originally Posted by Michael Schott

I disagree. First of all BMW recommends a 1200 mile break in period, not 3000 miles. Surely the parts will be well seated by then. Second, modern turbocharged engines are highly reliable. The proof is turbocharged diesel engines that routinely last 100's of 1000's of miles.

Naturally aspirated engines have less moving parts. turbo engines are put under higher stress especially when on boost. theres no argument here when it comes to which will be more reliable in the long run.

[Michael Schott]

Originally Posted by 6IX-F10-N52

Naturally aspirated engines have less moving parts. turbo engines are put under higher stress especially when on boost. theres no argument here when it comes to which will be more reliable in the long run.

That's true but in general modern cars are very reliable mechanically. Turbo or NA. I'm not sure why the OP asked this question but if reliability is a factor in choosing a new car, I wouldn't hesitate to buy a turbocharged car. In fact my last two were. First was a 2014 328i which was dead reliable over 65,000 miles which is too short a term for true long term reliability. And I didn't give a second thought to the turbo engine on my current VW GTI. I bought this car and plan on driving it at least 100,000 miles, possibly 150,000 or more.

[STR8-6IX]

Originally Posted by Michael Schott

That's true but in general modern cars are very reliable mechanically. Turbo or NA. I'm not sure why the OP asked this question but if reliability is a factor in choosing a new car, I wouldn't hesitate to buy a turbocharged car. In fact my last two were. First was a 2014 328i which was dead reliable over 65,000 miles which is too short a term for true long term reliability. And I didn't give a second thought to the turbo engine on my current VW GTI. I bought this car and plan on driving it at least 100,000 miles, possibly 150,000 or more.

I almost regret purchasing this N52 F10 sometimes - its a wonderful motor with a sweet engine note and very linear power delivery, but its just not the most ideal for hauling a 4000 pound boat of a sedan around. I always wonder what it would be like if i ended up going for a 535i.. but I just dont want to deal with fixing shit down the road. I got 67,000Miles on mycar currently, and while its not enough to test true long-term reliability like you said, the car has been bulletproof so far. the engine is in such good shape, I beat the shit out of it for 5000miles straight and the oil level still reads full when i go to get it changed.

[nicknaz]

Originally Posted by 6IX-F10-N52

anything turbo in general will be less reliable than naturally aspirate counterparts. alot of long term reliability depends on how the car was driven for the first 3000 miles. if you refrain from revving past 3-4K for this period, the piston rings and what-not will seat properly and ensure you dont burn a drop of oil down the road. this ensures that your engine lasts as long as possible. although this has nothing to do with the f30, the most reliable engines BMW every built was any inline 6 in the e46 or earlier. these engines are alot easier to work on compared to the newer stuff as well. when the new age of BMW engines was introduced (N52+) lots of complex electronics were added. IMO, the most reliable modern BMW engine is probably the N52.

Your advice on break in is heading into controversial territory. There's a school of school that your advice above is exactly what causes rings NOT to seal... btw, my n55, n52, n54 equipped cars all had a hard break in (circuit use within 300 miles of brand new) and they didn't burn oil and felt great.

I agree with n52 being my pick for most reliable modern BMW engine. Less stuff that can go wrong without turbos. N55 does seem reliable but the oldest versions of them are just exiting warranty now so we don't really know. Same with the s55. So far so good but too new to say for sure.

[STR8-6IX]

Originally Posted by nicknaz

Your advice on break in is heading into controversial territory. There's a school of school that your advice above is exactly what causes rings NOT to seal... btw, my n55, n52, n54 equipped cars all had a hard break in (circuit use within 300 miles of brand new) and they didn't burn oil and felt great.

I agree with n52 being my pick for most reliable modern BMW engine. Less stuff that can go wrong without turbos. N55 does seem reliable but the oldest versions of them are just exiting warranty now so we don't really know. Same with the s55. So far so good but too new to say for sure.

Im quite confused when it comes to the break in procedure. I am still convinced that its 5000KM. (I took my dads mazda 6 out one night when it had 3000 KM) and i COMPLETELY shat on it. was basically redlining it for the whole night. it unfortunately burns a little bit of oil now, nothing serious, but i feel like punching myself in the face for doing this to his car. now, before all of you start bleating that im using a MAZDA for an example on a BMW forum, keep in mind that an engine is an engine. its all the same design and the break-in procedure should apply for any new engine. just out of curiousity, how hard were you driving these new cars on the circuit? were you basically redlining the shit out of it, and also back to back? i feel like high revs repeatedly in the same period of time is what ruins a new motor.

my friend has a 2012 acura TL. him and his dad drive the absolute piss out of it. my friend said that for 100% his dad revved the shit out of it when new and it does not burn a single drop of 0w-20 oil 7000KM later. this whole thing is a tad confusing to me. if you shared in detail how you drove on the circuit, perhaps it will clear things up?

thanks!

[nicknaz]

This link is quite controversial http://mototuneusa.com/break_in_secrets.htm

I used that advice and there is in fact a section called "on the racetrack". Basically, it says to warm it up completely then go for it (similar to what your friend and his father did with their TL it sounds like)

If you didn't warm up your Mazda complete before hammering on it, that could be a concern. You could also check for an oil leak (my previous z435 had several gaskets leaking minor amount of oil in first year of ownership).

Edit: ask your dad to autox the Mazda with you rather than "borrowing" it to beat on it on the streets (aka street race it)....

[Michael Schott]

Originally Posted by 6IX-F10-N52

I almost regret purchasing this N52 F10 sometimes - its a wonderful motor with a sweet engine note and very linear power delivery, but its just not the most ideal for hauling a 4000 pound boat of a sedan around. I always wonder what it would be like if i ended up going for a 535i.. but I just dont want to deal with fixing shit down the road. I got 67,000Miles on mycar currently, and while its not enough to test true long-term reliability like you said, the car has been bulletproof so far. the engine is in such good shape, I beat the shit out of it for 5000miles straight and the oil level still reads full when i go to get it changed.

I had a loaner 535 a few years ago and while it was certainly fast enough I was thinking at the time that that car with the N20 would be marginal for a car of that size, weight and certainly stature. An N52 would be even worse.

[KGB_123_99]

N52 in an F30 would be a nice alternative to the N20. I miss that engine...

[STR8-6IX]

Originally Posted by nicknaz

This link is quite controversial http://mototuneusa.com/break_in_secrets.htm

I used that advice and there is in fact a section called "on the racetrack". Basically, it says to warm it up completely then go for it (similar to what your friend and his father did with their TL it sounds like)

If you didn't warm up your Mazda complete before hammering on it, that could be a concern. You could also check for an oil leak (my previous z435 had several gaskets leaking minor amount of oil in first year of ownership).

Edit: ask your dad to autox the Mazda with you rather than "borrowing" it to beat on it on the streets (aka street race it)....

I definitely made sure it was fully warmed up before hammering it. 100% no oil leak on a car with 60k KM

[STR8-6IX]

Originally Posted by KGB_123_99

N52 in an F30 would be a nice alternative to the N20. I miss that engine...

I've actually always thought how nice the n52 would be in the f30 as well.. agreed. what do you think of the n20? how does it compare to the n52 for you? ive actually never tried it before so im curious.

[KGB_123_99]

Originally Posted by 6IX-F10-N52

I've actually always thought how nice the n52 would be in the f30 as well.. agreed. what do you think of the n20? how does it compare to the n52 for you? ive actually never tried it before so im curious.

The N20 feels like it has more power (it does) but it feels nothing like the N52. The noise is not that great and the smoothness is not there. It just feels small and strained.

I would gladly take a fuel economy hit and lose a few HP to have a smoother engine. It's not all about power. My favorite was the M54.

[STR8-6IX]

Originally Posted by KGB_123_99

The N20 feels like it has more power (it does) but it feels nothing like the N52. The noise is not that great and the smoothness is not there. It just feels small and strained.

I would gladly take a fuel economy hit and lose a few HP to have a smoother engine. It's not all about power. My favorite was the M54.

Love the M54, loved the M50 in my e36 325i i had ages ago. but to me, nothing beats the N52. the torque from 2500-4000RPM is just peachy and it sounds SO GOOD. the sound, and engine itself is just so refined and smooth. the N20 is a good sounding 4 cylinder engine, but theres no comparison to the N52 also in terms of smoothness.

during real world driving, expect to see identical fuel economy figures between the N52 and N20 with their respective transmission choices. if you drive the n20 aggressively and on boost often (especially winding out past 5000rpm) the fuel economy will easily be worse. turbo engines get AWFUL fuel economy at high rpm's because the ECU dumps extra fuel into the engine under these conditions (run rich) in order to protect the engine from the immense heat. this is another reason why turbo engines tend to be less reliable. its alot of stress for the engine to be on boost all the time.