1. Rear Window Regulator Lifter for Electric Windows
Rear window regulators (both sides) are by far the top failing part in a BMW E90 Sedan or E91 Wagon. These window regulators are cable operated, and it is very common after time for the cables to snap or the clips break which jams your window and stops it operating.
Thankfully a replacement part is easy to come by as we have dozens of new aftermarket ones in stock ready to go. These rear window regulators are very high quality and we've been using them for years without any concerns. Fortunately 90% of the time you will not require a motor as it is almost always the regulator that fails, and not the electrical window motor. There are a few knacks to replacing the regulator but it can be done DIY if you have a bit of mechanical knowledge. We'd recommend watching this YouTube video to replace the regulator if it's your first time.
Right Rear Drivers Side Window Regulator
Left Rear Passengers Side Window Regulator
2. Electric Water Pump For 6 Cylinder Engines
a. Non-Turbo BMW 330i, 328i & 325i E90 / E91 / E92 N52 & N53 Engines
b. Turbo BMW 335i E90 / E91 / E92 N54 & N55 Engines
Another very commonly failing part is the electric water pump for BMW 6 Cylinder N52 / N53 & N54 / N55 engines. Specifically the N52B30A and N53B30A or B25 engines. It is very common that the genuine part will fail somewhere between the 90,000 to 120,000 km mark and most of the time it will bring up an engine light and have some fault codes logged. Commonly the faults 2E82 Electric Coolant Pump and 2E81 Speed Deviation faults. Sometimes your engine will get hot first, and bring on a warning light before which will be the first sign your BMW's waterpump is failing. Failures on these waterpumps aren't exclusive to 3 Series E90's though, they are also in 1 Series E87 125i / 130i's, 5 Series E60's, 6 Series E63 / E64, BMW X1, BMW X3, BMW X5 E70, BMW Z4 E85's.
There's a few tricks to replacing these, it's best practice to always replace the thermostat at the same time as well as the one time aluminum bolts which hold on the waterpump. It's also best to fully drain your coolant and replace it with 2-3 litres of high quality coolant and top it up with water too.
If you're doing it yourself it's a good idea to watch this video for some tips on replacing the waterpump, thermostat and alloy bolts.
N52 Non-Turbo Waterpump Link
N54 Turbo Waterpump Link
Thermostat Link
One Time Bolts Link
3. Alternator
All Alternators generally
do wear out after time and BMW E90's alternators are no different. You will generally know if your alternator is failing if your battery is consistently going flat even with regular driving and a good condition battery. Other signs are it can be overcharging which will normally bring up fault codes and could cause a light on the dash - this will need to be tested with a multimeter.
Both new and second hand are both good options depending on your budget as new one's can be a fair bit more expensive. However new Alternators do provide a lot more confidence in the parts reliability especially with a high quality brand like Valeo.
Alternators for 4 cylinder BMW E90s
Alternators for 6 cylinder BMW E90s
5. Starter motor For 6 Cylinder BMW's 325i, 330i, 335i, M3
Similarly to Alternators, starter motors on these BMW's usually fail at some point in there life. You can normally tell the starter motor is beginning to fail by it becoming slower to turn over. Other times it will just not make a noise even thought the lights are on the dash and the car has charge. It's best to check all fuses and check there is power to the motor before replacing the start motor. The most common starter motor to fail is the 6 cylinder ones in the N52, N53, N54 & N55 engines.
7. Valvetronic VVT Motor
If you notice an engine light pop on your BMW 3 Series then there's a good chance it's a failing VVT Motor. It will normally pop up some engine codes relating to valvetronic failure. It should be safe to drive to your mechanic, but it should be replaced pretty soon. The Variable Valve Timing Motor is placed on the top of the engine on the rocker cover. Check out this video if you want to see some tips on replacing it.
Buy VVT Motor for 4 Cylinder E90, N46 Engines
8. Gas Bonnet struts for all BMW E90s
There's nothing more annoying then a bonnet falling down on your head or onto the engine and denting the bonnet. This is a real risk and if your struts are failing you should fix these asap. Anyone can replace them themselves with a small flat head screwdriver.
9. Top Radiator Hose
Over time the top radiator hoses on these e90's become perished and often spring a leak. This can cause your BMW's cooling system to overheat and possibly cook your engine. If the hose is looking perished and likely to fail it's a good idea to replace it before it catches you out.
Buy Top Radiator Hose for BMW 6 Cylinder
10. Engine Ignition Coils
Very common reason for rough running and engine light on. Ignition coils are a bit like light bulbs, they tend to have a similar life so when one goes, it is likely the rest aren't far off either. It's always a good idea to replace all coils together to avoid the problem happening again soon after.
11. Washer motor bottle pump
Washer motor not working or leaking out the bottom? No stress, replace it with a good aftermarket part.
12. Cup Holders
Are you BMW E90 cup holders jammed? This is very common for almost all E90's over 12 years old, and it's usually the drivers cup holder which goes first. Unfortunately we don't currently stock any new cups holders, but we can try find you a good second hand part - just send us a message with your rego number.
13. Oil Level Sensor
Have you just replaced your oil and already being told by your car your oil level is low? Or are you getting inconsistent oil readings? Then you may have an oil level sensor fault, which is very common. The best way to determine this is by draining all your oil, measuring it, then re-filling it with the required spec.
Buy BMW E90 4 Cylinder Oil Level Sensor
Buy Diesel BMW E90 Oil Level Sensor
14. Oil Filter
Buy BMW N46 4 Cylinder Oil Filter
15. Rocker Cover Gasket
Are you smelling burning oil coming through your air vents or when
you open the bonnet? It's possible that your rocker cover gasket is leaking and dripping oil onto your exhaust manifold, which can become a major fire hazard. Usually a new rocker cover gasket and some sealant can fix this issue
Buy 335i Rocker Cover Gasket
Buy N46 4 Cylinder Rocker Cover Gasket
This article was designed with BMW 3 Series in mind including the models 318i, 320i, 325i, 330i, 335i, M3 and body shapes E90 LCL E91, E92, E93, Sedan, Coupe and Convertible. We are based in Hamilton New Zealand, but ship new Parts, Used Parts, Aftermarket Parts & Genuine Parts nationwide including major cities Auckland, Christchurch, Wellington, Dunedin and Nelson.