IsItAGoodCar
Reliability Guide

Common Problems with the
2019 BMW Z4 (G29)

The G29 Z4 was introduced in 2018 and went on sale in March 2019 as a 2019 model, built by Magna Steyr in Graz and sharing its architecture with the Toyota-supra. UK cars arrived as the sDrive20i, sDrive30i and M40i with the B58 six, and the soft top returned to the Z line after the E89's hard top.

What changed for 2019

  • •Return to a fabric roof, quicker to operate and lighter than the E89 folding steel top
  • •Co-developed sports car architecture with the parallel Toyota Supra
  • •M40i used the B58 six-cylinder engine, shared with the M2 and 3 Series

Common MOT watch-outs

  • !Roof mechanism, seals and pump faults, plus water ingress damage to interior electrics
  • !Exterior lighting and sensor damage on narrow front corners
  • !Tyre and brake wear, with the M40i eating discs and pads
3
Known Issues
0
Serious
2
Moderate
1
Minor

All Known Issues

Soft Top Wear Marks

ModerateBodywork & Rust

The compact multi-layer fabric soft top can rub against internal roof storage framework hinges when stowed behind the seats, causing shiny abrasion wear patches or premature fabric thinning on the outer canvas folds.

Est. Repair Cost: £0–£1,000
Warning Signs:

Shiny scuffed rub marks on both rear side quarters of fabric roof, Snagged threads or fabric fuzz along fold lines, Creaking or clicking noise as roof folds down

What to Inspect:
  • Lower the roof halfway into service position and inspect canvas around hinge pivot contact points
  • Check for dealer retrofitted protective felt strips in soft-top storage compartment
Verified by IsItAGoodCar Research Team

B58 Coolant Loss / PCV

ModerateEngine

The 3.0-litre turbocharged B58 straight-six engine in M40i models can experience slow coolant seepage from the water pump housing/cap or split the rubber crankcase ventilation (PCV) valve diaphragm integrated into the valve cover.

Est. Repair Cost: £150–£500
Warning Signs:

"Top up engine coolant" alert on digital cluster every few months, High-pitched whistling or chirping noise from engine at idle, White smoke from exhaust or sweet burnt-syrup odour after driving

What to Inspect:
  • Check both main and auxiliary coolant expansion tank levels and caps
  • Listen for whistling around the valve cover PCV round breather cap
  • Inspect lower engine undertray for dried blue/white coolant residue
Verified by IsItAGoodCar Research Team

iDrive Reboots

MinorElectrics & Electronics

The BMW Live Cockpit Professional with iDrive 7 can suffer from sudden operating system lockups, black display screen cutouts, or Bluetooth connectivity drops resolved through i-Step dealer or OTA software flashing.

Est. Repair Cost: £0
Warning Signs:

Central touchscreen or digital cockpit shuts down and restarts mid-journey, Apple CarPlay or Android Auto drops connection repeatedly, Navigation map freezes during route calculation

What to Inspect:
  • Verify current iDrive software version and check OTA update history menu
  • Test phone projection and radio audio during a 15-minute test drive
Verified by IsItAGoodCar Research Team

Buying Tips for 2019 BMW Z4 (G29)

  • Cycle the roof several times cold and check the boot liner for damp
  • Ask for evidence of any brake disc thickness measurement, because replacements exceed £900 per axle
20182020–2021
Check a 2019 BMW Z4 (G29) by Registration