Repair Cost Guide

BMW Timing Chain Replacement Cost: N47, N57, B47

BMW timing chain replacement costs vary dramatically by engine. N47 requires gearbox removal (£1,500-3,200). N57 front-mounted chain is cheaper. B47 most accessible.

📅 Updated Aug 2026 👁 45 views 🔗 2 related fault cases
Risk:
8/10
💰 Est. cost: £600 –£3,200

⚡ Quick Summary

📌 At a Glance
  • Risk score: 8/10
  • Est. cost: £600–£3,200
🔗 Backed By
  • 2 related fault cases from MyCarFault’s database
  • Last reviewed Aug 2026
  • 45 readers so far

How This Page Is Organised

This Repair Cost Guide guide combines structured analysis — verdicts, risk scoring and cost ranges where we have enough data — with real fault cases pulled directly from MyCarFault's reporting database, so the guidance below reflects what owners actually experience rather than manufacturer specifications alone. Background and analysis come first, followed by the linked fault reports and related guides you can jump to directly using the links above.

BMW timing chain replacement is one of the most discussed repairs in the premium car market. Costs vary enormously depending on which engine you have — the N47 diesel is the most expensive due to its rear-mounted chain position, while the B47 replacement is far more straightforward.

Cost Breakdown

N47 (318d/320d/520d)
£1,500-3,200
Gearbox removal usually required. Do clutch/DMF at same time.
N57 (530d/X5 30d)
£800-1,600
Front-mounted chain, much better access
B47 (318d/320d post-2015)
£600-1,200
Front chain, straightforward access
N20 (320i/520i petrol)
£700-1,400
Front chain but known tensioner weakness
B48 (320i post-2015)
£600-1,100
Good access, reliable chain

Related Guides

BMW N47 timing chain problems Timing chain replacement cost

Frequently Asked Questions

No — chain jump destroys the engine instantly. Stop driving if rattle persists beyond cold start.

Usually yes on E90/E91/E87. Some independent specialists have developed methods to avoid full gearbox drop but most require it.

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Important Notice: This page is based on owner reports, community discussions and MyCarFault case data. It is not an official manufacturer defect notice. Information about costs and reliability reflects community-reported experiences and may not apply to your specific vehicle. Always confirm diagnosis with a qualified mechanic before making repair or purchase decisions. MyCarFault makes no warranty as to the accuracy or completeness of any information on this page.
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