The N47 2.0-litre diesel is notorious for timing chain issues — but how common is failure really? This page breaks down the N47 failure rate, typical mileage at failure, and how it compares to other BMW engines using real UK enquiry data.
The BMW N47 2.0-litre diesel generated 1,450 UK enquiries in 2025 [EM-VERIFIED] — more than any other BMW engine we track. Its most common failure is timing chain stretch, typically occurring between 60,000 and 120,000 miles [PATTERN DATA], with reconditioned supply costs ranging from £3,200 to £5,500 [EM-QUOTE].
Full failure-rate context, mileage distribution, and comparison to other BMW engines below.
With 1,450 enquiries in 2025, the N47 is the most-requested BMW engine — but what does that tell us about its actual failure rate?
Enquiry volume is not the same as failure rate. The N47 was fitted to millions of cars across the BMW range between 2007 and 2014, so the absolute number of enquiries is partly a reflection of population size. However, the known failure pattern — timing chain stretch leading to catastrophic valve-train damage — is real and well-documented. BMW issued Technical Service Bulletins (TSBs) on the issue, and specialists consistently report it as the top reason for N47 engine replacement [EM-INTERVIEW].
In our 2025 data, the N47's 1,450 enquiries place it:
What is more telling is the proportional failure rate when adjusted for vehicle parc size. Based on our specialist interviews and industry estimates, the N47 has a higher proportional failure rate than the B47 and the B58, but is similar to the N57's crankshaft and turbo issues [PATTERN DATA]. The N47's timing chain problem is particularly prevalent in pre-2011 engines with the older tensioner design.
The table below shows 2025 enquiry volumes for BMW's most common engines, alongside typical failure mileage and repair costs.
| Engine | 2025 Enquiries [EM-VERIFIED] | Typical Failure Mileage | Recon Supply Cost | Primary Failure |
|---|---|---|---|---|
| N47D20C | 1,450 | 60–120k | £3,200–£5,500 | Timing chain stretch |
| B47D20A | 930 | 100–180k | £2,800–£4,500 | EGR cooler |
| N57D30 | 830 | 80–150k | £4,500–£7,000 | Timing chain / turbo |
| B58B30 | 540 | 60–120k | £3,800–£6,000 | Coolant leaks |
| N63B44 | 440 | 60–100k | £6,000–£10,000 | Valve seals / oil |
| N20B20 | 440 | 60–120k | £2,500–£4,500 | Timing chain tensioner |
All enquiry figures [EM-VERIFIED]. Cost and failure data [EM-QUOTE / EM-INTERVIEW / PATTERN DATA].
On this table, the N47 leads the pack in enquiry volume — but it is also one of the oldest engines here, with the largest vehicle parc. The key takeaway is that the N47's replacement cost is moderate compared to the N63 and N57, and its failure mode is well-understood and often preventable with a proactive timing chain inspection. The B47, its successor, is clearly more reliable, with fewer enquiries and a lower failure rate in our data.
When does an N47 typically fail? Our data suggests a cluster between 60,000 and 120,000 miles, with a notable peak around 80,000–90,000 miles.
This distribution is based on our [EM-INTERVIEW] data from specialists and [PATTERN DATA] from forum and TSB cross-reference. The timing chain tensioner is the primary culprit — it is a known weak point that tends to fail within this mileage band, especially on cars that have not had regular oil changes.
What the numbers show:
If your N47 is at 70,000–90,000 miles and you hear a rattle on cold start, that is the moment to act — not after the chain has slipped. A specialist can check tensioner wear during an oil service, and a £150–£300 inspection is far cheaper than a £3,200–£5,500 recon engine.
While timing chain stretch is the headline issue, the N47 has other known weak points.
The timing chain issue is the most catastrophic and the primary driver of engine replacement. The others are typically repairable without full engine replacement, though they can contribute to overall running costs.
The N47 is a capable engine with a known, preventable weak point.
In our view, the N47 is not a "bad" engine — it is a high-torque diesel with a specific, well-documented issue. It generates the most enquiries of any BMW engine we track, but that is partly due to its widespread use and age. Its timing chain problem is both earlier and more common than the B47's EGR cooler issues, but it is also much less costly than an N63 valve-seal failure.
The key recommendation is preventative maintenance. If your N47 is at 70,000 miles or more, have the timing chain tensioner checked at the next service. If you hear a cold-start rattle, act immediately. A £600–£1,200 preventative job is far cheaper than a £3,200–£5,500 replacement.
Verdict: Buy with confidence, but budget for a tensioner inspection at 70k. Avoid cars with patchy service history or a recorded cold-start rattle. On many F30 3 Series and F10 5 Series hosts, replacement is still financially viable — but check the vehicle value against our Repair vs Replace Calculator.
It is the most common single failure mode for this engine, with a typical occurrence between 60,000 and 120,000 miles. In our 2025 data, the N47 generated 1,450 UK enquiries, more than any other BMW engine [EM-VERIFIED].
The N47 was fitted to the F30 3 Series (316d, 318d, 320d), E90 3 Series, F10 5 Series (520d), E60 5 Series, F25 X3 (xDrive20d), E84 X1, F22 2 Series and many others. See the full fitment guide for all chassis codes.
Yes — the B47 is a significantly more robust engine, with a lower failure rate and fewer documented weak points. The N47's timing chain issue is well-known, while the B47's common issues (EGR cooler) are less catastrophic. We recommend the B47 over the N47 if reliability is your top priority.
Reconditioned supply is £3,200–£5,500; fitted with labour (10–14 hours) is £3,900–£6,500. Preventative chain replacement is £600–£1,200. [EM-QUOTE]
No — a rattle on cold start is a clear warning sign. Driving with a loose chain risks the chain jumping teeth, causing catastrophic engine damage. Have it inspected immediately by a specialist.
1,450 Real EnquiriesThe N47-specific dataset behind every figure on this page.
Limitations DisclosedWe state plainly what this data can't tell you, not just what it can.
Annual PublicationRefreshed every February — this is our founding baseline year.
100% IndependentNo sponsors, no manufacturer influence.
See where your specific engine and vehicle sit, and compare quotes from our vetted specialist network.
USE THE CALCULATOR → CHECK YOUR REGISTRATION