[Kevin_Trxn]

Originally Posted by rsyed07

I've had two N54s so far. One was a 2011 335is owned it from 45k miles to 77k miles then it got totaled. On my 2nd one now which is a 2013. Owned it since 47k miles and I know have 73k miles on it. First car had a chargepipe and a mild stage 1 tune. Never had issues except for leaking oil filter housing gasket, bad upper radiator hose, and a couple bad coils. I changed brakes, rotors, water pump, tstat, plugs, coils, (regular maintenance). I do all the maintenance on it myself so labor is out the question unless its something I don't have the proper setup for. Current N54 has been full bolt on for 15K miles and counting. Also same scenario, no major issues besides oil filter housing gasket as well. From what I have seen low mileage N54s (75k miles or less)have been trouble free. I think problems start when they reach closer to 100k miles as more maintenance upkeep is required to keep it healthy and trouble free. I prefer smaller twins over a twin scroll single. The car is lots of fun with 441whp on e30 fuel with lots of down low power. Plenty of room where I live to stretch it's legs and now with the XHP dct tunes coming out I plan to do more with it. Hope that helps a little with the view on the N54 side of things.

Thats some good info

[HadA335i]

I had a 2011 335i xDrive 6MT, bought it April 2017 with 52k and sold it last October at just under 70k miles. My car had just about everything that could go wrong with a N55 go wrong except for rod bearings. Just engine related work off the top my head:

- Waterpump/Thermostat
- Oil Filter Housing Gasket
- Oil Pan Gasket
- Belt Tensioner and Pully
- Power Steering Pump
- A/C Compressor
- Starter
- High Pressure Fuel Pump
- Valve Cover Gasket
- Coolant Expansion Tank
- Valvetronic Actuator
- Eccentric Shaft

Except for the last two the rest can go bad on an N54 car too. I had other non-engine related stuff break too. I did regular maintenance like fluid changes and spark plugs. Around 62k I got MHD Stage 1+ so the car wasn't tuned for most of the time I owned it.

With these cars your experience, at least reliability-wise, will be most decided by how well the prior owner(s) took care of the car. If they were the type to abuse the car and put repairs off you might be stuck with a basket case like I was.

[Js235]

you should go for N54 if your plan is to modify it

[Emilime75]

If there's one thing that would keep me from buying an N55, it is all of the reports of engines seizing after an OFHG job.

Aren't they also more prone to rod bearing failure?

Anyway, if I was in the market for an E92, it would be a 35is. When I bought my 2010 E92 335i about 2.5 years ago, the is had about a $10-12k premium in my area and I didn't feel it was worth it, at the time.

[solo118]

Originally Posted by HadA335i

I had a 2011 335i xDrive 6MT, bought it April 2017 with 52k and sold it last October at just under 70k miles. My car had just about everything that could go wrong with a N55 go wrong except for rod bearings. Just engine related work off the top my head:

- Waterpump/Thermostat
- Oil Filter Housing Gasket
- Oil Pan Gasket
- Belt Tensioner and Pully
- Power Steering Pump
- A/C Compressor
- Starter
- High Pressure Fuel Pump
- Valve Cover Gasket
- Coolant Expansion Tank
- Valvetronic Actuator
- Eccentric Shaft

Except for the last two the rest can go bad on an N54 car too. I had other non-engine related stuff break too. I did regular maintenance like fluid changes and spark plugs. Around 62k I got MHD Stage 1+ so the car wasn't tuned for most of the time I owned it.

With these cars your experience, at least reliability-wise, will be most decided by how well the prior owner(s) took care of the car. If they were the type to abuse the car and put repairs off you might be stuck with a basket case like I was.

Sorry to hear about all of your issues, but the same issues for the most part apply to the N52 as well. Many people here replace many of these parts as preventative maintenance, especially the gaskets you mentioned.