BMW 3 Series E90 320d N47 2.0d 177bhp — Electric Window Regulator Cable Failure
The cables inside the electric window regulator mechanism fray and snap, causing the window glass to drop into the door frame.
Severity
MinorDIY Difficulty
Moderate
Est. Cost
£100–£200
OBD Codes
None
Symptoms
- Grinding or crunching noise when operating the window switch
- Window glass drops down into the door and won't come up
- Window sits crooked in the frame
Root Cause
The steel cables run over plastic pulleys. The plastic pulleys degrade and crack, or the cable frays and tangles inside the motor drum.
How To Fix
- Remove the interior door card to access the regulator.
- Tape the window glass 'up' temporarily to secure the vehicle.
- Replace the entire window regulator mechanism (usually supplied without the motor).
- Cost: £100-200
Estimated Repair Costs
| Repair Option | Est. Cost (GBP) |
|---|---|
| DIY (parts only) | £40–£80 |
| Independent Garage | £100–£200 |
| Main Dealership | £160–£320 |
Other Faults on This Variant
N47 Timing Chain Failure (Rear of Engine)
CriticalThe BMW N47 diesel engine has a timing chain positioned at the REAR of the engine, against the bulkhead. Chain failure is catastrophic, and repair requires engine removal. This is the most significant known fault in the BMW 3 Series range.
Swirl Flap Failure and Engine Ingestion
CriticalThe N47 intake manifold has metal swirl flaps on actuator rods. When the rods corrode and snap, the flap breaks off and gets ingested into the engine, causing severe internal damage.
EGR Cooler and Valve Failure
ModerateEGR cooler failure on the N47 is common from 70,000 miles. Coolant leaks into the intake manifold and the EGR valve sticks, causing power loss and rough running.
Disclaimer: Repair cost estimates are indicative and based on community data. Always get a quote from a qualified mechanic before proceeding with any repair.