BMW 4 Series common problems & fixes (F32/F33/F36 2013–2020, G22/G23/G26 2020–)

Written by the C4R team from DVSA data and owner reports. Fact-checked 2026-10-13.

30-second verdict

A used BMW 4 Series coupe, convertible or Gran Coupe is a stylish, sharp-driving buy, but check its recall history and listen for timing chain rattle. It suits drivers who value handling and looks over outright practicality. Diesels built 2013–2020 were covered by several EGR cooler fire-risk recalls, 2013–2017 builds have airbag recalls and 2019–2025 builds have starter motor recalls, so get every campaign confirmed against the VIN. The early 2.0 N47 diesels and N20 petrols are the ones to listen to most carefully. The safer picks are a 2016-on 420i, 430i or 440i petrol, or a later B47 420d with its EGR recalls signed off if you cover enough motorway miles to keep its particulate filter healthy, always with a full service history.

Generations at a glance

Generation	UK years	Main engines and gearboxes	Notes
F32 Coupe, F33 Convertible, F36 Gran Coupe (early cars)	Coupe 2013–2020; Convertible 2014–2020; Gran Coupe 2014–2020	Petrol: 420i and 428i (2.0 N20), 435i (3.0 N55). Diesel: 418d, 420d and 425d (2.0 N47, replaced by the B47 from 2015, the 425d from 2016), 430d and 435d (3.0 N57). Six-speed manual as standard or optional eight-speed automatic; xDrive four-wheel drive on some	Convertible has a three-piece folding metal roof; Gran Coupe has five doors and a hatchback-style tailgate. DVSA recall records show first-generation builds running to September 2020
F32, F33, F36 (2016 engine update and 2017 facelift)	2016–2020	420i and 430i (2.0 B48) replace the N20 petrols; 440i (3.0 B58) replaces the 435i; four-cylinder diesels now the B47	Facelift unveiled January 2017: new lights and bumpers, updated iDrive and stiffer suspension on the Coupe and Gran Coupe
G22 Coupe, G23 Convertible, G26 Gran Coupe	Coupe from 2020; Convertible from late 2020; Gran Coupe from 2021	420i (2.0 B48), M440i xDrive (3.0 B58 with 48-volt mild-hybrid help), 420d (2.0 B47), 430d and M440d xDrive (3.0 B57); eight-speed automatic only	Convertible switches to a fabric roof; UK diesels were dropped when the range was revised in 2024

This guide covers the regular 4 Series in all three body styles, including Gran Coupe adverts. The high-performance M4 and the electric i4 are different cars and are not covered here.

Known issues

1. Diesel EGR cooler recalls (2013–2020 builds)

Label: Confirmed recalls R/2018/258, R/2018/341, R/2021/037, R/2021/213, R/2022/206 and R/2022/255

What you notice: Usually nothing obvious. The leak happens inside the cooler, which is why BMW inspects it with an endoscope or simply replaces it.
Which cars: 418d, 420d, 425d, 430d and 435d Coupes, Convertibles and Gran Coupes. The original UK campaign covered 4 Series diesels built from May 2013 to July 2017, and later DVSA-listed campaigns stretch the build windows into 2018 and, for R/2022/206, to September 2020. Only a VIN check tells you which campaigns apply to one car.
Why: Coolant can leak inside the exhaust gas recirculation (EGR) cooler. Combined with soot and oil residue in the EGR module, it can build up deposits that may ignite.
Fix: Free at a BMW dealer. Depending on the campaign, the cooler is inspected with an endoscope and replaced if leaking, the cooler module is replaced outright, or (R/2022/255) the diesel engine control software is reprogrammed with better leak detection.
DIY difficulty: 5/5. This is dealer recall work only.
Check when buying: Run the GOV.UK recall check, then ask a BMW dealer to confirm every EGR campaign is closed against the VIN. There were several separate campaigns, so one recall invoice does not prove the others were done. Auto Express reported owners who only learned of the recall when they booked a routine service.
Evidence: The DVSA recall records set out the defect and remedies; Which? listed the 4 Series diesel models and build months in the UK campaign; Auto Express reported parts shortages, long waits and owners who never received recall letters.

2. Airbag recalls on 2013–2017 builds

Label: Confirmed recalls R/2023/016, R/2024/403 and R/2025/349 (plus R/2017/011 for a small 2016 batch)

What you notice: Nothing in normal driving. The danger only shows if the airbag goes off.
Which cars: R/2023/016 covers Coupes built 07/05/2013–18/12/2015, Gran Coupes built 02/12/2013–29/06/2017 and Convertibles built 22/10/2013–29/06/2016. R/2024/403 covers 2013–2017 builds that may have had a previously recalled Takata driver's airbag fitted later as a retrofit or conversion; the airbag fitted at the factory is not affected. R/2025/349 covers 2013–2017 cars that were already under airbag recalls in a market where they previously lived, which mainly matters for imported cars.
Why: For R/2023/016, the DVSA record says the propellant in the driver's airbag may degrade, so it could burn too aggressively and rupture the inflator body. For R/2024/403 and R/2025/349, a previously recalled driver or passenger airbag could deploy with excessive force and release sharp metal fragments.
Fix: Free at a BMW dealer: the driver's airbag module is replaced (R/2023/016), or the airbags are checked and replaced where needed (R/2024/403, R/2025/349).
DIY difficulty: 5/5. Airbag work is for a BMW dealer only.
Check when buying: Get written confirmation that the airbag campaigns are closed for the VIN. Be extra careful with imported cars and cars with crash-repair history. The airbag warning light must go out after starting; an SRS warning lamp showing a fault is a major MOT defect.
Evidence: The DVSA recall records describe each airbag campaign and its remedy; the GOV.UK MOT inspection manual lists an SRS malfunction lamp showing a fault as a major defect.

3. Timing chain wear on early 2.0 engines

Label: Reported by owners and independent specialists

What you notice: A rattling noise from the engine. On the N47 diesel it comes from the rear of the engine, where the chain sits. If the chain slips or breaks, serious engine damage can follow.
Which cars: 418d, 420d and 425d with the N47 diesel (to 2015, 425d to 2016), and 420i and 428i with the N20 petrol (to 2016). Later B47 diesels and B48 petrols replaced these engines.
Why: The chain, its plastic guides and the tensioner wear. Wikipedia's N20 entry reports that thousands of early N20 engines were built with faulty plastic chain guides. Auto Express says earlier versions of BMW's four-cylinder diesel had a reputation for serious timing chain and turbo trouble, and advises sticking closely to the service schedule.
Fix: Before failure, replace the chain, guides and tensioner. The N47 chain sits at the rear of the engine, and a UK BMW engine specialist says repairs mean taking the engine out. After a failure, the same specialist lists £3,000–£4,000 plus VAT to rebuild an N47 built 2009–2015 (UK specialist price list, accessed October 2026).
DIY difficulty: 5/5.
Check when buying: Listen to a genuinely cold start with the bonnet up, and again as the engine warms. Ask for invoices for any chain work, and look for regular oil changes in the history. Walk away from a rattling car, or price a chain job into your offer.
Evidence: Auto Express's used 4 Series guide; Wikipedia's N47 and N20 engine entries; Prestige German Engines, a UK BMW engine rebuilder, on chain location and rebuild prices. The same specialist's timing chain page also prices rebuilds for the later B47 diesel, so a cold-start listen is worthwhile on any 4 Series diesel.

4. Starter motor recalls on 2019–2025 builds

Label: Confirmed recalls R/2026/054 and R/2025/405

What you notice: Possibly nothing, or false starts when you try to start the engine. In the worst case there is a fire risk.
Which cars: R/2026/054 covers Coupes built 18/08/2020–25/04/2025, Convertibles built 23/09/2020–25/04/2025 and Gran Coupes built 16/04/2021–05/05/2025, which is mainly the second-generation car. R/2025/405 covers a small number of Coupes built 05/12/2019–24/07/2020 and Convertibles built 11/02/2020–10/03/2020.
Why: Under R/2026/054, wear inside the starter relay can leave deposits that cause false starts or a short circuit. Under R/2025/405, water can get into the starter, corrode it and cause a short circuit.
Fix: Free at a BMW dealer: the starter motor is replaced. Under R/2026/054 the replacement comes from a different supplier with a different design.
DIY difficulty: 5/5. This is dealer recall work only.
Check when buying: R/2026/054 only launched in March 2026, so check carefully whether the work has been done. Until it is, the DVSA records recommend not leaving the car running unattended after starting (R/2026/054) and parking outdoors away from buildings (R/2025/405). Ask for proof that the work is booked or done.
Evidence: The DVSA recall records for R/2026/054 and R/2025/405.

5. Blocked DPF on short-trip diesels

Label: Inspection point

What you notice: An orange DPF warning light, loss of power or limp-home mode. During a regeneration you may notice cooling fans running, a raised idle, stop-start not working and a hot, acrid smell.
Which cars: All 4 Series diesels, especially low-mileage cars used mainly for short, slow journeys.
Why: The filter has to burn off its soot, and that needs a decent run. The RAC says short, low-speed journeys are the main cause of blocked filters, and that about 10 minutes above 40mph may be enough to complete an active regeneration.
Fix: Find out why the filter is blocking before you replace anything. The RAC puts a forced regeneration at a garage at about £100–£250 and specialist cleaning at about £200–£500; replacement costs vary widely by model. Removing the filter is illegal and fails the MOT.
DIY difficulty: 2/5 for a regeneration drive; 4/5 for diagnosis and parts.
Check when buying: Ask how the car has been used, take a test drive of at least 20 minutes, and make sure no warning lights appear. If most of your driving is short trips, Auto Express suggests a petrol 4 Series instead.
Evidence: Auto Express's owner feedback warns that low-mileage 4 Series diesels may develop DPF problems; the RAC's DPF guide covers causes, symptoms, prices and legality.

6. Corroded or kerbed alloys and worn run-flats

Label: Inspection point

What you notice: Corrosion around the wheel centre caps, kerbed rims, a car that pulls to one side, or tyres worn unevenly.
Which cars: All models. Every first-generation car runs on run-flat tyres with no spare wheel.
Why: Auto Express says corrosion around the centre caps is common on the first-generation car, and that all first-generation 4 Series models come on run-flat tyres. Tyres are also the most frequent MOT failure item for most 4 Series registration years in published analysis of DVSA test data.
Fix: Refurbish corroded or damaged wheels, have the suspension and four-wheel alignment checked after any heavy kerb strike, and replace tyres with the correct run-flat type.
DIY difficulty: 1/5 to inspect; wheel refurbishment and alignment need a specialist.
Check when buying: Inspect all four wheels and tyres, including the inner edges. Uneven wear can point to alignment or suspension problems.
Evidence: Auto Express on centre-cap corrosion and run-flats; Motorwise's analysis of DVSA MOT results on tyre failures.

7. Convertible roof operation and leaks

Label: Inspection point

What you notice: A roof that stops partway or will not move, damp carpets or headlining, or creaks and rattles from the roof over bumps.
Which cars: F33 Convertible (2014–2020), which has a three-piece folding metal roof. The G23 Convertible (from late 2020) has a fabric roof instead.
Why: A folding roof is a complex powered mechanism with many seals, so any fault or leak is worth finding before you buy.
Fix: Have roof faults diagnosed by a BMW dealer or convertible specialist before any parts are replaced.
DIY difficulty: 4/5.
Check when buying: Open and close the roof several times with the engine running, watching for hesitation or warning messages. Check the carpets, boot and headlining for damp, and drive over rough roads with the roof up.
Evidence: Wikipedia's F32 and G22 entries for the roof types.

8. Electrical checks and the Gran Coupe BDC recall

Label: Inspection point

What you notice: Warning messages, or features such as sensors, cameras, screens or gearshift paddles not working.
Which cars: Gran Coupes built 23/08/2021–26/09/2022 are covered by recall R/2023/071 for an incorrect setting in the Body Domain Controller (BDC). One Carbuyer owner of a 2017 440i reported the wiring loom for the gearshift paddles failing, fixed under warranty.
Why: Modern 4 Series cars depend on many control units and sensors, so wiring or software faults can show up as odd warnings.
Fix: Read the fault memory with a BMW-capable diagnostic tool and check for software updates before you replace any parts. If the car is still under BMW warranty, report faults to a dealer.
DIY difficulty: 2/5 for checks; 4/5 for repairs.
Check when buying: Test the iDrive screen, every sensor and camera, the paddles, seats, windows and lights. Ask for a diagnostic scan.
Evidence: DVSA's record for R/2023/071; a Carbuyer owner review of a 2017 440i.

Recalls (DVSA data)

These are the records filed under the 4 Series Coupe, Convertible and Gran Coupe model names (M4 excluded) in the DVSA recalls CSV downloaded on 2026-10-07, summarised in our own words. Refs, launch dates and build windows are copied from the file. Where the CSV gives one row per body style or several build windows for the same ref, we have merged them into one row and kept every window. Some older records are filed under the misspelt model name "4 SEPIES". Not every car built in a window is affected, so check the exact car by VIN.

DVSA ref	Launch date	Build window	Summary
R/2026/054	02/03/2026	Coupe 18/08/2020–25/04/2025; Convertible 23/09/2020–25/04/2025; Gran Coupe 16/04/2021–05/05/2025	Wear in the starter relay can cause false starts, a short circuit and possible fire; starter replaced with a different design
R/2025/349	18/12/2025	Gran Coupe 29/03/2014–25/10/2017; Coupe 27/06/2013–23/10/2017; Convertible 16/07/2013–27/10/2017	Cars already under airbag recalls in a previous market may have driver or passenger airbags that deploy too forcefully; airbags checked and replaced if needed
R/2025/405	27/10/2025	Coupe 05/12/2019–24/07/2020; Convertible 11/02/2020–10/03/2020	Water can get into the starter motor and corrode it, risking a short circuit; starter replaced
R/2025/407	06/10/2025	25/07/2025–25/07/2025	A power-supply screw connection in the boot may not have been tightened properly; connection reworked
R/2024/403	21/10/2024	Coupe 07/05/2013–08/11/2017; Convertible 12/11/2013–08/11/2017; Gran Coupe 02/12/2013–08/11/2017	A previously recalled Takata driver's airbag may have been fitted later as a retrofit; airbag checked and replaced if needed
R/2023/071	20/03/2023	Gran Coupe 23/08/2021–26/09/2022	Body Domain Controller may have an incorrect setting; settings checked and the unit reset if needed
R/2023/016	24/01/2023	Coupe 07/05/2013–18/12/2015; Gran Coupe 02/12/2013–29/06/2017; Convertible 22/10/2013–29/06/2016	Driver's airbag propellant may degrade, so the inflator could rupture; driver's airbag module replaced
R/2022/255	22/08/2022	Convertible 17/06/2015–01/03/2018; Gran Coupe 01/07/2015–26/02/2018 and 01/10/2021–01/10/2021; Coupe 11/11/2014–27/10/2018	Undetected EGR leaks could lead to overheating in the intake manifold; engine control software reprogrammed. The CSV lists a one-day Gran Coupe window in October 2021, reproduced as given.
R/2022/206	01/08/2022	Coupe 07/05/2013–08/06/2020; Convertible 22/10/2013–25/06/2020; Gran Coupe 02/12/2013–23/09/2020	EGR cooler may leak over time and overheat; EGR cooler module replaced
R/2021/213	14/06/2021	Coupe 20/03/2017–28/09/2018; Convertible 21/03/2017–25/09/2018; Gran Coupe 20/03/2017–24/09/2018	EGR module could leak and overheat; cooler inspected with an endoscope and replaced if leaking
R/2021/085	15/03/2021	27/01/2021–03/02/2021; 27/01/2021–05/02/2021	Brake discs may not have been made to specification; discs checked and replaced if necessary
R/2021/037	09/02/2021	29/06/2015–14/06/2018; 28/02/2015–20/07/2018; 27/02/2015–26/07/2018	Coolant leaking from the EGR cooler can mix with soot and oil to form deposits that may ignite; endoscope inspection, cooler replaced if leaking
R/2021/015	25/01/2021	17/08/2020–25/09/2020	Battery cables on the 48-volt starter-generator may not have been secured; connections checked and reworked
R/2018/341	07/12/2018	08/05/2013–11/04/2017; 22/10/2013–12/04/2017; 02/12/2013–10/04/2017	EGR cooler may leak, with a fire risk; cooler inspected and replaced on all affected cars
R/2018/258	05/11/2018	04/12/2014–18/07/2017; 10/11/2014–18/07/2017; 17/06/2015–16/05/2017	EGR cooler may leak, with a fire risk; replaced with an improved cooler
R/2018/260	15/10/2018	15/05/2018–29/05/2018; 16/05/2018–28/05/2018; 16/05/2018–25/05/2018	Crankshaft sensor may have a software fault; sensor replaced
R/2018/211	20/08/2018	23/05/2018–07/06/2018; 18/05/2018–06/06/2018; 29/05/2018–06/06/2018	Diesel crankshaft sensor firmware fault can trigger reduced-power emergency mode and possibly a stall; sensor replaced
R/2017/244	01/09/2017	07/07/2017–18/07/2017	Outer bolt on the front seat mechanism may not be secure, so the seat could move in a rear-end crash; bolt checked and replaced if needed
R/2017/011	10/01/2017	08/08/2016–14/11/2016	Some airbag igniters may have been made incorrectly, affecting deployment; affected airbag modules replaced
R/2016/300	21/12/2016	19/09/2011–08/12/2015	Electric power steering control unit contacts may not last, so assistance can fail and local overheating cannot be ruled out; steering gear replaced. The CSV window starts before 4 Series production began, reproduced as given.
R/2016/224	04/10/2016	01/01/2015–01/09/2016	Rear axle support bolts may have been reused after repair work, which can affect handling; bolts replaced
R/2015/109	08/06/2015	01/09/2013–30/04/2014	In-tank fuel pump parts may not have been plated correctly, causing a no-start or stall; fuel pump replaced
R/2014/188	06/01/2015	01/09/2014–31/03/2015	Driver's seat belt retractor may jam or be hard to pull out in sub-zero temperatures; belt checked and replaced if needed

Run the GOV.UK vehicle recall check, then ask a BMW dealer to check the VIN for completed and outstanding campaigns.

MOT watch-points

C4R has not yet calculated its own MOT statistics for the 4 Series, so this guide gives no pass rates or failure percentages. These checks are based on published analysis of DVSA test data and the official MOT inspection manual:

Tyres: Motorwise's analysis of DVSA first-test results puts tyre condition at the top of 4 Series failures for most registration years. Check tread across the full width, including the inner edges of run-flats.
Suspension and dampers: In the same analysis, rear shock absorbers lead the failures on the oldest 2013 cars. Look for leaking dampers and listen for knocks.
Brakes: Rear brake pads also appear among the more frequent failure items for 2019 cars. Ask when the pads and discs were last replaced.
Airbags and seat belts: An SRS warning lamp showing a fault, or a seat belt retractor that does not work as intended, is a major defect.
Diesel emissions: A car whose particulate filter has been removed will fail the MOT.

Read the individual car's history on the GOV.UK MOT history service and look for advisories that come back year after year.

Buying one? Our checklist

Run the registration through the GOV.UK recall checker, then get a BMW dealer to confirm every campaign is closed against the VIN, especially the EGR, airbag and starter motor recalls.
Read the MOT history for repeat tyre, damper, brake and suspension advisories.
Start the engine from cold with the bonnet up and listen for chain rattle, especially on N47 diesels and N20 petrols. Ask for any chain invoices.
Check the service history for regular oil changes and servicing on schedule.
On a diesel, ask how the car has been used and make sure no DPF or engine warnings appear on a 20-minute test drive.
Make sure the airbag warning light goes out after starting, and check that every seat belt pulls out and retracts smoothly.
Inspect all four wheels and tyres for corrosion, kerbing and uneven wear; first-generation cars have no spare wheel.
On a Convertible, cycle the roof several times and check the cabin and boot for damp.
Test the iDrive screen, sensors, cameras, paddles, seats and windows, and ask for a diagnostic scan.
On an imported car, ask whether it was under an airbag recall in its previous country (R/2025/349).

Running costs

Road tax: For 4 Series cars registered before 1 April 2017, tax depends on the CO2 band on the V5C, from £20 a year (bands A and B) to £790 (band M). Cars registered from 1 April 2017 pay the £200 standard rate, plus a £440 supplement for five years from the second time the car is taxed if the list price was over £40,000, making £640 a year (GOV.UK).
Insurance groups (first generation): Auto Express lists group 30 for a 420i Sport and group 31 for a 420i M Sport, with a 435d xDrive above group 40.
Insurance groups (second generation): Drive lists group 30 for the 420i M Sport, group 32 for the 420d, group 40 for the M440i and group 42 for the M440d xDrive.
Official economy: Auto Express quotes up to 50.4mpg (WLTP) for a first-generation 420d, plus official figures of 45.6mpg for a 420d xDrive automatic, 37.7mpg for a 420i automatic and 37.2mpg for a 430i. Drive quotes WLTP figures of up to 44.8mpg for the second-generation 420i and 36.2mpg for the M440i xDrive.
Servicing: The service schedule is variable, and the car tells you when it is due, typically every 18,000 miles or two years. Brake fluid is due every two years, and every engine has a timing chain rather than a cambelt (Auto Express).

Sources & further reading

Official data and checks

Generations and engines

Reliability, faults and buying advice

Contains public sector information licensed under the Open Government Licence v3.0.

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