[KennyP]

I guess all z4 35i owners read e90 forums for troubleshooting and DIY guides. I for sure do. More information available. On engine issues i dont even bother searching Z4 forum and just search for N54 + issue and that usually takes you to e90post or n54tech. And of course youtube has a lot of info on N54 aswell.

Engine is the same and has the same common issues as in any other chassis.

With 3 series there are maybe more problems with early cars... 2007-2008...
Early cars did not have oil coolers for example... and so on.

Z4 came out 2009 so some of these early issues were already updated...

Owned mine for 5 years and this is what i have had to do to the car:

Front adaptive shocks started leaking. Replaced with KW V3 coilover kit.
DCT had a leak: Had DCT service done that included new pan gasket.
felt loss of power: New ignition coils and 1 step colder n55 plugs.
Oilfilter housing oil leak : replaced gaskets, aux belt and tensioner.
Smelled oil inside the cabin: replaced valve cover.
Again smelled oil inside cabin : replaced chain tensioner.
Front wheel bearings made noise: replaced both front wheel bearings.
Have done intake valves carbon cleaning once during my ownership. Was a 400 eur bill. Here nobody does walnut blasting... so found a guy who did it manually(usually on Audis).
Replaced and registered new battery.( Had original battery for 9+ years)
Have replaced all my vacuum lines with new Samco silicone vacuum lines. (preventative maintenance)
Have replaced rear lights because moisture issue.
Have replaced rear licence plate lights (one died).
Replaced drivers seat bottom heater element(Bottom did not heat up well and backrest was not regulating its temp and got hotter and hotter. Got so hot in 5-10 minutes that you turned heating off because it got painful.)
New oil filler cap.

Fortunately got the car with newest version index 12 injectors already on it. So no problem there. Fuel pumps still fine, water pump still fine. Of course maybe some of it was replaced by previous owner. I dont have any records of that. Injectors definitely were changed by him.

On top of this i have done cosmetic stuff... detailing, polishing, paintwork, all new exterior BMW badges, new windshield, new tweeter grilles, wheel refurb twice.



In 4000km i have front and rear brake pads and discs coming up. Probably going to do rear wheel bearings at the same time. Have only changed my pads once before.
And im looking for a new used steering wheel with paddles and heating.

First 2 years were pretty much problem free... most of my issues started around 2019 when car got 10 years old. All the leaks, first shocks then gearbox then engine leaks.

Car has around 70k miles on it now.