Quick Facts — BMW 4 Series

Est. On UK Roads
150,000+
Years Made
2013–present
Common Engines
420i, 428i, 430i, 440i, M4, 418d, 420d, 425d, 430d, 435d

6 Most Common BMW 4 Series Problems

These are the faults most frequently seen on the BMW 4 Series by UK garages — ranked by how commonly they occur and what they cost to fix.

1
N47 Diesel Timing Chain (F32 Early)
High Priority
Early F32 4 Series with the N47 diesel engine retain the timing chain risk. Check carefully on pre-2015 diesel 420d and 418d models.
💷 Typical repair cost: £2,000–£4,000+
2
B47/B57 Diesel EGR and DPF
Watch
Newer diesel 4 Series develop EGR and DPF issues. Short-journey use accelerates DPF blockage. DPF warning and limp mode are the symptoms.
💷 Typical repair cost: £200–£1,200
3
Convertible Roof Mechanism (F33)
Watch
The F33 convertible folding roof can develop hydraulic leaks and mechanism faults. Slow operation or failure to open/close are the symptoms.
💷 Typical repair cost: £400–£1,500
4
N55 / B58 Turbo Oil Leaks
Watch
Higher-mileage 4 Series with the N55 and B58 turbocharged petrol engines can develop valve cover gasket and turbo feed pipe oil leaks.
💷 Typical repair cost: £200–£600
5
iDrive Screen Failure
Watch
The large iDrive touchscreen on newer 4 Series can develop pixel issues or go black. A common fault on older units.
💷 Typical repair cost: £300–£800
6
Adaptive LED Headlight Faults
Low Priority
Individual LED elements within the adaptive headlights can fail, triggering a warning light and requiring headlight unit replacement — which is expensive.
💷 Typical repair cost: £500–£2,000

Got a BMW 4 Series Fault?
Free Fault Scan →

Describe your symptoms and MotorLoom cross-references known BMW 4 Series fault data — giving you likely causes, UK repair costs and MOT risk instantly.

Find Your Problem Now →
First cause free · Full report £1.99 · 60 seconds

BMW 4 Series — MOT Tips

Check N47 timing chain on early diesel models. DPF warning light is an automatic fail. Adaptive LED failures will trigger a warning light which is MOT-relevant. Verify convertible roof seals on F33.

Engine management light on before your MOT? It's an automatic fail. Run a Find Your Problem Now → to get the likely cause and repair cost before booking the test.

BMW 4 Series Tyres

Most BMW 4 Series models run 225/50 R17 or 245/40 R18 depending on trim level and year. Always check the placard inside the driver's door for the exact size for your vehicle.

🔍 Not sure what's wrong? Check your symptoms & likely causes →

🔗 Trusted Partner
BookMyGarage
Need to get a BMW 4 Series fault fixed? Find and book a trusted local garage — compare prices and availability instantly.
Find a Local Garage →
🔗 Trusted Partner
Tyres.net
Need new tyres for your BMW 4 Series? Get an instant price and book fitting near you.
Get a Tyre Price →
🔗 Trusted Partner
AutoAid Breakdown Cover
Driving a BMW 4 Series? Get UK breakdown cover from AutoAid — one of the UK's most affordable and highly rated breakdown services. From just £33/year.
Get a Quote →

Partner links — MotorLoom may earn a small commission at no extra cost to you.

Frequently Asked Questions

What is the most common problem with the BMW 4 Series?

The most frequently reported issue on the BMW 4 Series is N47 Diesel Timing Chain (F32 Early). Early F32 4 Series with the N47 diesel engine retain the timing chain risk. Check carefully on pre-2015 diesel 420d and 418d models.

How many BMW 4 Seriess are on UK roads?

There are an estimated 150,000+ BMW 4 Seriess currently on UK roads.

What tyres does the BMW 4 Series use?

Most BMW 4 Series models run 225/50 R17 or 245/40 R18 depending on trim level and year. Always check the placard inside the driver's door for the exact size for your vehicle.

Will a warning light fail my BMW 4 Series's MOT?

Check N47 timing chain on early diesel models. DPF warning light is an automatic fail. Adaptive LED failures will trigger a warning light which is MOT-relevant. Verify convertible roof seals on F33.

Similar Issues on Other Models

Audi A5 — shares the same convertible roof mechanism problem BMW 3 Series — also commonly develops n47 diesel timing chain

Summary

The 4 Series is a stylish, well-built car. Pre-2015 diesel models carry the N47 timing chain risk. Later models are more reliable but EGR and DPF maintenance on diesels remains important.

If your BMW 4 Series has a warning light on or a symptom you can't identify, a Find Your Problem Now → gives you likely fault causes, UK repair cost estimates and MOT risk — instantly.

BMW 4 Series Warning Light On?
Free Fault Scan →

Instant fault analysis, UK repair costs and MOT risk for your exact BMW 4 Series.

Find Your Problem Now →
First cause free · Full report £1.99 · No subscription · Instant results

Other BMW Models

BMW 1 Series → BMW 2 Series → BMW 3 Series → BMW 5 Series →