[Steve.T]

I posted this in the American section in error but got some interesting answers. I wondered what the home team think.

So, I am well aware of all the associated problems with the 335 engine but my question is; when did BMW get it together. Is there a year that we are ‘fairly’ safe from problems or does the ‘relative’ reliability start from the F30’s? I am currently on the lookout for a 330i e90/92 but would happily take a 335i if the right spec turned up. All of the later ones appear to have been specced with the DCT box and I’m not interested in that. Was DCT standard on the 335 LCI models? It seems that way looking at all the adverts over the last couple of months. I don’t do much mileage (perhaps 4K per year) and I live in central London so an ‘old school’ auto works best for me. The fact is I would rather stick with the NA engine if all the 335 e90/2’s are susceptible to the usual problems. Would I be safer(ish) with an early F30 335 or are they still a risk?Apologies for all the questions, I have had ten years of reliable E46 bliss and don’t want my BMW experience sullied in the future.

Cheers
Steve

[Parmb24]

Steve the associated problems with the 335i are typically related to the N54 engine which is effectively the twin turbo engine produced from 2007-2009. After this the N55 engine was released part way though in 2009 using a single turbo charger but replicating the twin turbos through twin scroll technology. Look for a N55 335i between 2009-2013 if your after a E9* shape car. As for gearbox I would highly recommend DCT (Dual clutch tranmission) over the standard autobox for the following reasons -
1) Faster Shifting (so quickthat you do not loose boost in between shifts)
2) Less power transfer loss. Automatics are usually around 20%-22% power loss, while DCT and manuals usually stick around 15%.
3) More fuel efficient. Manuals in general are more fuel efficient than BMW's 6 speed automatics. Although I must say BMW's new 8-speed ZF auto is more fuel efficient than the DCT. Most automatics lose their power and fuel efficiency in the torque converter.
4) Faster shifting response. Automatics although they are much faster than they were a couple years ago still lag a bit when you tap the paddle. DCT is extremely responsive.
5) Launch Control
6) Throttle blip downshift. The DCT automatically rev matches when downshifting which sounds pretty incredible once you get a exhaust on the car. The automatic does not really have a need to do the whole throttle blip due to the way an automatic transmission works.

I've just come from a manual M135i to a DCT E92 335i and was a bit apprehensive to begin with however the DCT is absolutely sublime! I would highly recommend. DCT was also a ~£2,000 option from factory.

[Steve.T]

Originally Posted by Parmb24

Steve the associated problems with the 335i are typically related to the N54 engine which is effectively the twin turbo engine produced from 2007-2009. After this the N55 engine was released part way though in 2009 using a single turbo charger but replicating the twin turbos through twin scroll technology. Look for a N55 335i between 2009-2013 if your after a E9* shape car. As for gearbox I would highly recommend DCT (Dual clutch tranmission) over the standard autobox for the following reasons -
1) Faster Shifting (so quickthat you do not loose boost in between shifts)
2) Less power transfer loss. Automatics are usually around 20%-22% power loss, while DCT and manuals usually stick around 15%.
3) More fuel efficient. Manuals in general are more fuel efficient than BMW's 6 speed automatics. Although I must say BMW's new 8-speed ZF auto is more fuel efficient than the DCT. Most automatics lose their power and fuel efficiency in the torque converter.
4) Faster shifting response. Automatics although they are much faster than they were a couple years ago still lag a bit when you tap the paddle. DCT is extremely responsive.
5) Launch Control
6) Throttle blip downshift. The DCT automatically rev matches when downshifting which sounds pretty incredible once you get a exhaust on the car. The automatic does not really have a need to do the whole throttle blip due to the way an automatic transmission works.

I've just come from a manual M135i to a DCT E92 335i and was a bit apprehensive to begin with however the DCT is absolutely sublime! I would highly recommend. DCT was also a ~£2,000 option from factory.

Thanks for the info. TBH, I really wouldn't take on the risk of a DCT as living in central London it would never get out of third gear, they have the potential to cost an awful lot In the event of a problem and I believe more likely to be problematic than a TC box. I'm not bothered with launch control. Again, central London and I can lay waste to pretty much everyone in town at the traffic light Grand Prix with my girlfriends Citroen saxo 1.0, never mind my 330 in 'sport mode' and the diff loaded up. If I lived outside of London I'd consider it but I really wouldn't get the benefit in town and other than London driving I only do a the occasion motorway trip now and again. FWIW you sell it well 😉

Cheers
Steve

[texasjohn]

Steve

The N55 has its own problems. Overall it's a more reliable unit but can more expensive to resolve than N54.

I wouldn't own one out of warranty, put it that way.

I ended up getting mine fixed and then sold it. Fortunately BMW UK provided a huge goodwill gesture.

I didn't find the F3x 340i all that nice to drive, the E9x platform has more character and better steering. I had one and sold it again pretty quickly, now in an F10.

Give me a call if you want to chat and catch up. Have a E90/92 sub enclosure for sale too (mates rates lol) if you do end up buying a E again �

I would head towards a 330i most probably, but I only need one car.

[keyap]

This may be worth a read:

https://www.e90post.com/forums/showthread.php?t=755057

[RajB]

Due to age/mileage nowadays I wouldn't generally worry about the N54 (2006 upwards ) as most common issues will have generally been dealt with. But as long as you do some decent checks and look for ones with decent receipts/history you should be ok.

There are plenty of decent independents and fixes for many issues, and of course if something does break you can just upgrade/mod it instead

[harvs43]

Originally Posted by RajB

Due to age/mileage nowadays I wouldn't generally worry about the N54 (2006 upwards ) as most common issues will have generally been dealt with. But as long as you do some decent checks and look for ones with decent receipts/history you should be ok.

There are plenty of decent independents and fixes for many issues, and of course if something does break you can just upgrade/mod it instead

Totally agree, once all the issues are sorted with the latest parts you will be fine with an N54 which I think is a better engine incidentally. I loved mine and miss it even though I am in an F31 .....