Mercedes-Benz CLA: common faults & what to check

Which Mercedes-Benz CLA are you looking at?

4 generation variants documented. Pick the shape you recognise: the faults, the servicing and the timeline below all narrow to it. Free, no account needed.

Petrol

4 variants documented

2013–2020C1172013–2020C1171.6 turbo petrolPetrolDocumented issues4 knownSee faults & what to checkPhoto: MercurySable99 via Wikimedia Commons, CC BY-SA 4.0.

2013–2020C1172013–2020C1172.0 turbo petrolPetrolDocumented issues5 knownSee faults & what to checkPhoto: MercurySable99 via Wikimedia Commons, CC BY-SA 4.0.

2019–nowC1182019–nowC1181.3 turbo petrolPetrolDocumented issues5 knownSee faults & what to checkPhoto: Vauxford via Wikimedia Commons, CC BY-SA 4.0.

2019–nowC1182019–nowC1182.0 turbo petrolPetrolDocumented issues3 knownSee faults & what to checkPhoto: Vauxford via Wikimedia Commons, CC BY-SA 4.0.

Now narrow it to the engine

A 1.8 and a 2.4 of the same car do not fail the same way, so the faults below narrow to the engine as well as the year. Free, no account needed.

Start your free check on this Mercedes-Benz CLA

No plate needed. You get the risk score, the buyer's checklist and the guided inspection for the exact car you picked above — not the whole nameplate.

The checks worth doing on a Mercedes-Benz CLA before you hand over any money. Every documented fault is listed below, each with its own page.

• Costly issue

  Cold-start test is essential.

  See why

  M270/M282 Timing Chain Cold-Start Rattle (C117/C118)

  CLA models from C117 (2013–2019, M270 engine) through C118 (2019–present, M282 engine) carry the same oil-pressure-dependent hydraulic chain tensioner found across the Mercedes compact platform. Cold-start timing chain rattle is widely documented across CLA 180, CLA 200 and CLA 250 variants. The performance-oriented CLA 250 with its higher-stress M270 specification is particularly noted for tensioner wear when oil change intervals are extended.

  What you would notice

  • Rattling from front of engine on cold start for 2–5 seconds
  • Persistent rattle in neglected examples
  • P0016/P0017 OBD fault codes
  • Rough cold idle that stabilises once oil pressure builds

  Typically $2,000–$4,500 to put right.

• Costly issue

  Ask for the service history and whether the turbo oil feed line campaign (2014120001) was done or the turbo has been replaced.

  See why

  Turbo failure from contaminated oil feed line (CLA 45 AMG 2.0 M133 turbo)

  On the CLA 45 AMG's 2.0 M133 turbo petrol, the strainer in the turbocharger oil feed line could become contaminated, starving the turbo bearings of oil and wearing them out early. Mercedes ran a service campaign (2014120001, early 2015) on 2014-15 model year cars: dealers measured turbo shaft play and replaced the turbo and oil feed lines where play was too high, with about a quarter of cars needing a new turbo. A car that missed the campaign can still have a worn turbo, so ask a Mercedes dealer whether it was completed on the VIN.

  What you would notice

  • Whistle or siren noise from the turbo under boost
  • Blue or grey smoke from the exhaust
  • Loss of power or limp mode
  • Oil use between services

  Typically $0–$9,000 to put right.

• Costly issue

  Multiple slow pull-away tests at low speed on flat ground.

  See why

  7G-DCT / 8G-DCT Dual-Clutch Shudder and Judder (C117/C118)

  C117 CLA models use the same 7G-DCT dual-clutch as the A and B-Class compact range, with the same documented low-speed shudder. C118 models (2019+) received the revised 8G-DCT which is improved but still exhibits shudder when transmission fluid is degraded. The CLA's coupé styling attracts drivers who use the DCT more aggressively, which can accelerate clutch pack wear in early units.

  What you would notice

  • Shudder when pulling away from rest
  • Judder in slow car park manoeuvring
  • Hesitation or clunk on light-throttle low-speed take-off
  • Occasional unexpected kickdown or gear hunting at low speed

  Typically $900–$4,200 to put right.

• Costly issue

  Be there for a cold start and sit with it as it idles, because that is when a carboned engine is at its worst.

  See why

  M282 intake valve carbon build-up — rough idle, misfires and flat spots

  The M282 petrol is direct injection, which means fuel is sprayed straight into the cylinder rather than past the intake valves. Nothing then washes those valves clean, so carbon deposits build on them over time and gradually choke the airflow. It shows as a rough idle, misfires and flat spots in the power delivery, and it comes on so slowly that owners usually adapt to it rather than notice it. Short journeys and gentle driving accelerate it. The repair is a cleaning job rather than a mechanical failure, but it is a labour-heavy one because the intake has to come off, and it will need doing again — so it is a running cost to price in rather than a one-off. A car with a full service history and regular open-road use is meaningfully better here.

  What you would notice

  • Rough or uneven idle, worst from cold
  • Misfire — a stumble or hesitation when accelerating
  • Flat spot in the power delivery at low to mid revs
  • Engine warning light, sometimes with misfire codes
  • Fuel economy quietly worse than it used to be

  Typically $600–$2,200 to put right.

• Costly issue

  This one is best judged on a genuinely cold start, so try to see the car before it has been moved.

  See why

  M282 thermostat failure — slow warm-up, or overheating

  Thermostat failure is one of the named weak points on the M282, and it fails in two directions that feel completely different from the driver's seat. Stuck open, the engine never reaches proper operating temperature: the heater blows lukewarm, the car uses more fuel than it should, and the engine wears faster because it spends its life running cold. Stuck closed, coolant cannot circulate and the temperature climbs — which is the version that damages things. The first is easy to dismiss as the car being a bit slow to warm up on a cold morning, which is exactly why it goes unfixed for months. The part is not expensive; the consequences of the closed version are.

  What you would notice

  • Engine taking much longer than usual to reach normal temperature
  • Heater blowing lukewarm rather than hot, especially at idle
  • Temperature gauge sitting lower than normal, or climbing in traffic
  • Engine warning light with coolant temperature codes
  • Fuel economy noticeably worse in cold weather

  Typically $400–$1,600 to put right.

• Costly issue

  Ask the seller for the service history and whether the starting current limiter recall (extra starter fuse) was done by a Mercedes dealer.

  See why

  CLA starting current limiter overheating fire recall PRA 2017/16367 (C117 CLA sold February 2015 to January 2017)

  On C117 CLA models (all engines) sold in Australia from 31 January 2015 to 31 January 2017, the starting current limiter in the starter circuit can overheat if the starter is cranked over and over while the engine or gearbox is jammed. Mercedes recalled these cars in Australia (PRA 2017/16367, listed for the C117 CLA range by sale date) and in the USA (NHTSA 17V-114, CLA250 and CLA 45) because the heat can melt nearby parts and start a fire. The fix is an extra fuse in the starter feed, fitted free by a Mercedes dealer. Recalled cars are listed by VIN, so ask a Mercedes dealer to check this one.

  What you would notice

  • Usually no warning before the fault
  • Burning or melted plastic smell after a hard start or repeated cranking
  • Starter clicks or cranks but the engine will not turn over

  Typically $0–$400 to put right.

What these repairs cost on other cars

Some of the Mercedes-Benz CLA’s documented faults are repairs other models share. Each page lists the documented NZ cost for every model it affects.

• Timing Chain Replacement Cost
• DSG and Dual-Clutch Gearbox Repair Cost
• Turbo Repair and Replacement Cost

Other Mercedes-Benz models