CriticalAffected: 2012-201580,000–140,000 miles

BMW 3 Series F30 320d N47 2.0d 184bhp — Timing Chain Failure (N47 Engine)

While BMW revised the N47 engine for the F30, the timing chain can still stretch and snap, destroying the engine, especially if oil changes are stretched to 18,000 miles.

Severity

Critical

DIY Difficulty

Professional Only

Est. Cost

£1000–£3000

OBD Codes

None

Component Diagram

Timing Chain

Typical layout and location for the Timing Chain assembly.

Reference Illustration

Symptoms

Distinct, rhythmic 'ch-ch-ch' metallic scraping noise from the back of the engine
Noise increases with RPM
EML light for camshaft/crankshaft correlation faults

Root Cause

The chain guides wear and the chain stretches. The chain is located at the rear of the engine, meaning the entire engine must be removed to replace it.

How To Fix

Preventative: Halve the BMW oil change interval to 9,000 miles/1 year.
If rattling: Engine out, replace upper and lower chains, tensioners, and guides.
Cost of preventative chain replacement: £1,000-£1,400
Cost if it snaps: £3,000+ for a replacement engine.

Estimated Repair Costs

Repair Option	Est. Cost (GBP)
DIY (parts only)	£400–£1200
Independent Garage	£1000–£3000
Main Dealership	£1600–£4800

Other Faults on This Variant

Steering Rack Clunk (EPS Failure)

Moderate

2012-201940,000–90,000 miles£150–£250

The F30 generation uses an Electronic Power Steering (EPS) rack which frequently develops an internal mechanical clunk, especially over uneven surfaces.

EGR Cooler Recall / Fire Risk

Critical

2012-201830,000–150,000 miles0

A huge global recall affects the F30 320d due to the EGR cooler leaking glycol coolant into the intake manifold, which mixes with soot and can catch fire.

ZF 8-Speed Automatic Gearbox Sump Leak

Moderate

2012-201960,000–110,000 miles£350–£500

The plastic sump pan on the excellent ZF 8-speed automatic gearbox warps over time, causing transmission fluid to leak.

Disclaimer: Repair cost estimates are indicative and based on community data. Always get a quote from a qualified mechanic before proceeding with any repair.