Faults by part: what fails on each engine and car
Choose the part (the turbo, the EGR valve, the timing belt, the shock absorbers, the electric handbrake, the airbags…) and we show you every fault documented on the engines and cars we analyse: symptoms, how much they cost to repair and which models are affected.
Engine
Timing drive, turbo, injection, emissions control, lubrication, cooling and ignition.
- Timing belt29 faults · 29 engines · 219 affected modelsCritical severityGarage: €400–€1,500
- Timing chain47 faults · 46 engines · 309 affected modelsCritical severityGarage: €350–€7,000
- Variable valve timing (VVT) actuator11 faults · 11 engines · 65 affected modelsCritical severity
- Turbo67 faults · 64 engines · 427 affected modelsCritical severityGarage: €150–€3,000
- EGR valve62 faults · 60 engines · 437 affected modelsCritical severityGarage: €60–€2,500
- Particulate filter (DPF/FAP)39 faults · 37 engines · 312 affected modelsHigh severityGarage: €100–€3,000
- AdBlue (SCR) system and NOx sensor18 faults · 18 engines · 163 affected modelsMedium severityGarage: €100–€2,000
- Injectors57 faults · 54 engines · 446 affected modelsCritical severityGarage: €80–€5,900
- Fuel pump and high-pressure pump28 faults · 27 engines · 214 affected modelsCritical severityGarage: €250–€2,000
- Oil consumption48 faults · 46 engines · 277 affected modelsCritical severityGarage: €900–€4,000
- Oil leaks27 faults · 23 engines · 138 affected modelsCritical severityGarage: €200–€2,200
- Water pump38 faults · 38 engines · 267 affected modelsCritical severityGarage: €300–€1,500
- Thermostat and cooling system42 faults · 38 engines · 283 affected modelsCritical severityGarage: €300–€760
- Head gasket13 faults · 12 engines · 83 affected modelsCritical severity
- Ignition coils and spark plugs37 faults · 37 engines · 210 affected modelsHigh severityGarage: €120–€600
- Carbon build-up in the intake26 faults · 26 engines · 220 affected modelsMedium severityGarage: €110–€310
- Intake flaps (swirl flaps)9 faults · 9 engines · 74 affected modelsCritical severityGarage: €600–€1,200
- Engine sensors29 faults · 28 engines · 177 affected modelsHigh severityGarage: €100–€3,000
- Catalytic converter6 faults · 4 engines · 29 affected modelsCritical severity
- Lambda sensor10 faults · 10 engines · 64 affected modelsMedium severity
- Mass airflow sensor10 faults · 10 engines · 61 affected modelsHigh severityGarage: €100–€300
- Intercooler and turbo hoses8 faults · 8 engines · 67 affected modelsCritical severity
- Glow plugs3 faults · 2 engines · 3 affected modelsCritical severity
- Spark plugs8 faults · 8 engines · 61 affected modelsHigh severity
- Radiator and electric fan4 faults · 4 affected modelsCritical severity
- Exhaust and silencers13 faults · 4 engines · 39 affected modelsHigh severity
- Big-end bearings and pistons13 faults · 12 engines · 107 affected modelsCritical severity
- Crankshaft pulley and engine mounts5 faults · 5 engines · 51 affected modelsHigh severity
- Hybrid system66 faults · 9 engines · 78 affected modelsCritical severity
- High-voltage battery (hybrids and EVs)65 faults · 24 engines · 97 affected modelsCritical severity
Gearbox, clutch and transmission
Manual, automatic, dual-clutch and automated gearboxes, clutch and dual-mass flywheel.
- Clutch209 faults · 29 engines and gearboxes · 309 affected modelsCritical severityGarage: €340–€4,000
- Dual-mass flywheel68 faults · 20 engines and gearboxes · 204 affected modelsCritical severityGarage: €340–€4,000
- Dual-clutch gearbox (DSG, EDC, PowerShift...)64 faults · 7 gearboxes · 117 affected modelsCritical severityGarage: €450–€3,100
- Automatic gearbox (torque converter and CVT)89 faults · 12 engines and gearboxes · 147 affected modelsCritical severityGarage: €120–€2,000
- Automated manual gearbox (Dualogic, Easytronic, MMT...)27 faults · 5 engines and gearboxes · 56 affected modelsCritical severity
- Gearbox mechatronic unit14 faults · 12 gearboxes · 158 affected modelsHigh severityGarage: €600–€3,100
- Manual gearbox106 faults · 10 engines and gearboxes · 176 affected modelsCritical severityGarage: €340–€4,000
- Driveshafts, propshaft and four-wheel drive77 faults · 7 engines · 81 affected modelsCritical severity
- Driveshafts and CV joints25 faults · 1 engine · 26 affected modelsCritical severity
- Differential23 faults · 1 engine · 23 affected modelsCritical severity
Suspension, steering, brakes and wheels
Shock absorbers, control arms and ball joints, power steering, brake servo, ABS and tyres.
- Shock absorbers and top mounts130 faults · 128 affected modelsCritical severityGarage: €700
- Air and hydropneumatic suspension42 faults · 42 affected modelsCritical severity
- Suspension springs47 faults · 47 affected modelsCritical severityGarage: €400–€750
- Control arms, ball joints, bushes and drop links244 faults · 226 affected modelsCritical severityGarage: €300–€750
- Wheel bearings and hubs67 faults · 67 affected modelsCritical severity
- Rear axle60 faults · 55 affected modelsCritical severity
- Handbrake and parking brake105 faults · 104 affected modelsCritical severityGarage: €250–€550
- Brake servo and vacuum pump99 faults · 4 engines · 116 affected modelsCritical severity
- Brake calipers, discs and pads105 faults · 104 affected modelsCritical severity
- Brake pedal, hoses and brake fluid98 faults · 90 affected modelsCritical severity
- ABS and stability control (ESP)115 faults · 112 affected modelsCritical severityGarage: €200–€2,100
- Power steering114 faults · 111 affected modelsCritical severityGarage: €850
- Steering rack and steering column147 faults · 138 affected modelsCritical severityGarage: €850
- Tyres, wheels and wheel bolts78 faults · 72 affected modelsCritical severityGarage: €650–€750
- Tyre pressure sensors8 faults · 8 affected modelsHigh severity
Electrics and electronics
Batteries, alternator, wiring, control units, infotainment and driver assistance systems.
- 12 V battery98 faults · 6 engines · 105 affected modelsCritical severityGarage: €120–€500
- Alternator and starter motor75 faults · 2 engines · 81 affected modelsCritical severity
- Wiring, connectors and short circuits160 faults · 16 engines · 202 affected modelsCritical severity
- Window regulators and central locking138 faults · 135 affected modelsCritical severityGarage: €150–€250
- Headlights and lights85 faults · 79 affected modelsCritical severity
- Parking sensors and cameras30 faults · 29 affected modelsHigh severity
- Key, remote and keyless start28 faults · 28 affected modelsCritical severity
- Start-stop system10 faults · 1 engine · 14 affected modelsMedium severity
- Screen and infotainment system197 faults · 191 affected modelsHigh severityGarage: €350–€700
- Instrument cluster45 faults · 45 affected modelsHigh severity
- Driver assistance and automatic emergency braking99 faults · 91 affected modelsCritical severity
- Control units and comfort electronics (BSI, SAM...)51 faults · 47 affected modelsCritical severityGarage: €600–€800
- eCall system29 faults · 29 affected modelsCritical severityGarage: €0
Climate control, bodywork and interior
Air conditioning, heating, water leaks, paintwork, rust and panoramic roof.
- Air conditioning90 faults · 86 affected modelsCritical severityGarage: €170–€1,100
- Heating and heat pump29 faults · 29 affected modelsCritical severity
- Water leaks73 faults · 68 affected modelsCritical severity
- Paintwork, rust and corrosion114 faults · 107 affected modelsCritical severity
- Sunroof and panoramic roof52 faults · 51 affected modelsCritical severity
- Tailgate, bonnet and bodywork parts83 faults · 81 affected modelsCritical severity
- Windscreen and windows24 faults · 24 affected modelsCritical severity
- Windscreen wipers28 faults · 22 affected modelsCritical severity
- Seats and interior63 faults · 60 affected modelsCritical severity
Airbags and safety
Airbags, seatbelts, fire risk and fuel leaks.
- Airbags319 faults · 276 affected modelsCritical severity
- Takata airbags58 faults · 58 affected modelsCritical severity
- Seat belts109 faults · 105 affected modelsCritical severity
- Fire risk131 faults · 22 engines · 172 affected modelsCritical severityGarage: €500–€1,500
- Fuel leaks27 faults · 10 engines · 75 affected modelsCritical severity
- Accelerator pedal6 faults · 1 engine · 8 affected modelsCritical severity
Prefer to start with what you notice? Search by symptom (a warning light, a noise, smoke) or describe the problem in the diagnosis.