"Is the 3 Serisi 320d reliable, and what should you check?"
When buying a used BMW 3 Series 320d 2009 (E90 / E91 / E92 / E93 / facelift), the most frequently mentioned issues are: carbon buildup in the EGR and intake manifold, turbo problems. Also, timing chain breakage/slack is commonly reported.
Engine: N47
N47D20C · 320d · Used in this car from 2008-2014
Strengths
Wide selection of versions and modifications
Economical for such power output
Watch-outs
Many problems with early diesel versions
Frequent oil leaks
Many versions have piezo injectors
Known engine issues
Timing chain driveEarly engines had low timing chain lifespan: guides wore out, chains stretched, and sharp teeth on the crankshaft sprocket accelerated the process. On updated N47TU or N47N engines, most weak points were eliminated.
Cracks in the blockThe aluminum block was initially designed without a special safety margin, and severe overheating could cause cracks between the second and third cylinders. With the update, the block was reinforced and such problems almost ceased.
Fuel systemAll engines in this series are equipped with a reliable Bosch Common Rail fuel system, but powerful versions with piezo injectors are quite demanding on fuel quality. Also, avoid driving with an empty tank, as the high-pressure pump may suck in air and start producing metal shavings.
Listed from most frequently reported, each with its source.
Carbon buildup in EGR and intake manifold, turbo problems
Often reported
User reports indicate carbon and oil deposits in the intake manifold and EGR valve, leading to power gaps, exhaust odor, and possible gas pressure faults.
Engine Bay
Timing chain breakage/slack
Often reported
The N47 engine is known for timing chain issues: the chain, tensioner, and guides can wear or slacken prematurely, causing metallic noises and potentially severe engine damage.
Timing chain
Diesel Particulate Filter (DPF) clogging
Often reported
In city driving, the 320d's DPF can clog or fail to regenerate, causing a DPF warning light and power loss or limp mode.
Exhaust Emissions
BMW 3 Serisi 320d technical specs
BMW 3 Serisi 320d (2009): boot 440 L; fuel use 4,8 l/100 km (urban 6 l/100 km · extra-urban 4,1 l/100 km); 0–100 in 7.9 s.
Boot capacity
440 L
Fuel consumption
4,8 l/100 km (urban 6 l/100 km · extra-urban 4,1 l/100 km)
What should I look for when buying a BMW 3 Series 320d?+
When buying a 2009 320d, check the service history, test drive, and look for engine/transmission warnings. The most commonly reported issues: carbon buildup in the EGR and intake manifold, turbo problems; timing chain breakage/slack; Diesel Particulate Filter (DPF) clogging.
What are the common problems of the BMW 3 Series 320d?+
The most frequently reported issues: carbon buildup in the EGR and intake manifold, turbo problems; timing chain breakage/slack; Diesel Particulate Filter (DPF) clogging.
Is the BMW 3 Series 320d reliable?+
Rather than a simple yes/no, it's best to weigh the proven pros and cons together. This page lists 3 verified findings.
How does Carbeak collect data?+
The cards on this page are derived from Difetti fault database records; the source vehicle and target vehicle are verified for brand, fuel, engine, and generation compatibility. Topics with insufficient evidence are not shown.