IsItAGoodCar

Common Problems with the
2020–2023 BMW 4 Series (G22/G23/G26)

We've identified 3 known issues that can affect the 2020–2023 BMW 4 Series (G22/G23/G26). None are considered critical, but they're worth knowing about before you buy.

3
Known Issues
0
Serious
3
Moderate
0
Minor

The 2020–2023 period has 1 more issue than the BMW 4 Series (G22/G23/G26) average across all year periods.

All Known Issues

Radar Sensor Misalignment

ModerateElectrics & Electronics

The front radar sensor located in the large kidney grille is vulnerable to even minor "nudges", which can knock it out of alignment and disable the cruise control and safety systems.

Most affected: All models with Driving Assistant Professional

Estimated cost: £200–£500Affects: 2020–2024Often appears around: N/A

Typical symptoms

  • •"Driver Assistance Restricted" warning on dash
  • •Active Cruise Control refusing to engage
  • •Emergency braking system warnings

What to inspect before you buy

  • ✓Inspect the radar sensor for any visible cracks or impact marks
  • ✓Ask for a diagnostic report if any assistance warnings are present
  • ✓Check if the sensor bracket is loose

Coolant Loss (B58 Engine)

ModerateCooling System

The M440i can suffer from slow coolant loss, often from the expansion tank cap or a minor weep from the water pump or turbo cooling lines.

Most affected: M440i, M440d

Estimated cost: £50–£300Affects: 2020–2024Often appears around: 15,000–40,000 miles

Typical symptoms

  • •Low coolant warning on the iDrive
  • •Sweet smell of coolant after a spirited drive
  • •Dried white residue around the expansion tank cap

What to inspect before you buy

  • ✓Check the coolant level when the engine is stone cold
  • ✓Inspect the expansion tank for hairline cracks
  • ✓Look for any signs of blue or green residue on the front of the engine

Active Grille Shutter Motor Failure

ModerateCooling System

The motorised flaps behind the front grilles can fail to open or close correctly, throwing an engine management light and affecting aerodynamics.

Most affected: 420i, 420d, 430i

Estimated cost: £300–£600Affects: 2020–2023Often appears around: 20,000–50,000 miles

Typical symptoms

  • •Check Engine Light (EML) with air flap codes
  • •Flaps stuck in one position
  • •Fan running more than usual

What to inspect before you buy

  • ✓Verify the shutters move during the vehicle's startup sequence
  • ✓Check for any debris (leaves/stones) lodged in the mechanism

Buying Tips for the 2020 BMW 4 Series (G22/G23/G26)

  • ✓Check the front grille area carefully for any stone damage or minor impacts, as the radar sensors are very exposed
  • ✓On M440i models, monitor the coolant level closely; the B58 engine is generally reliable but can have slow seeps
  • ✓Test the convertible roof (G23) and the Gran Coupe (G26) frameless windows for smooth, silent operation
  • ✓Verify the latest iDrive 7 or 8 software is installed to avoid known navigation and connectivity bugs
2024 BMW 4 Series (G22/G23/G26)

Browse 2020–2023 BMW 4 Series (G22/G23/G26) in our Directory

View MOT history, registration data, and reliability scores for 2020–2023 BMW 4 Series (G22/G23/G26) vehicles.

View 2020–2023 Directory

Other BMW 4 Series (G22/G23/G26) Year Periods

2020–20232024

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