Used car guide · 1993–2026

Mercedes-Benz C-Class common problems and MOT failures

What goes wrong on a used Mercedes-Benz C-Class, year by year: known faults from UK buying guides, the parts flagged at MOT more than on other cars (from 1,117,998 MOTs done during 2023–2025), and what to check before you buy one.

The 1993 Mercedes-Benz C-Class

Too few Mercedes-Benz C-Class cars first registered in 1993 had an MOT during 2025 for reliable MOT figures. There are no known faults on record for this year in the UK buying guides we use, so the rest of this page covers the Mercedes-Benz C-Class as a whole.

82on the UK register at the end of 2025
Dieselmost common fuel (also petrol)
What to check on a 1993 car
  • MOT history

    Check the reg below: its MOT history shows what has been failed or advised, and whether the mileage adds up.

  • Service history

    Look for regular servicing and receipts for big jobs like a cambelt or clutch.

  • Finance and write-offs

    MOT records don’t show outstanding finance or insurance write-offs. A history check does.

  • Test drive

    Listen for knocks over bumps, check every warning light goes out, and make sure the gears and brakes feel right.

Other years

Most years have their own guide. The year is when the car was first registered (it’s on the logbook, or check the reg below).

2026202520242023202220212020201920182017201620152014201320122011201020092008200720062005200420032002200120001999199819971996199519941993

Generation guides: Mercedes-Benz C-Class W204 (2008–2014) · Mercedes-Benz C-Class W205 (2014–2021)

What usually goes wrong with a Mercedes-Benz C-Class?

Known faults reported by owners, mechanics and UK buying guides, in our own words. Most apply to certain years or engines only, so check which the car has.

  • Fuel pump recall

    Cars registered 2022–2023 · All engines

    Some 2022-23 cars were recalled because the fuel pump impeller can deform.

    At the viewing: Run the free DVSA recall check on the reg.

    Source: What Car?: Mercedes C-Class (2021 on) reliability

  • Diesel emissions system faults

    Cars registered 2014–2021 · Diesel

    Particulate filter, NOx sensor and AdBlue problems are the main worry on diesels, especially ones used for short trips.

    At the viewing: Watch for emissions or AdBlue warnings on the dash, and ask what journeys it’s done.

    Source: Parkers: Mercedes C-Class (2014-2021) used review

  • Air suspension

    Cars registered 2014–2021 · Cars with air suspension

    Cars with air suspension can develop expensive faults that need a specialist.

    At the viewing: Check the car sits level all round, look for uneven front tyre wear, and watch for suspension warnings.

    Source: Parkers: Mercedes C-Class (2014-2021) used review

  • Petrol smell or leaks (petrol)

    Cars registered 2014–2021 · Petrol

    Petrol models can leak fuel from the pump area or crack plastic air pipes.

    At the viewing: Smell around the car after a cold start, and listen for rough idle.

    Source: Parkers: Mercedes C-Class (2014-2021) used review

  • Injector seals (diesel)

    Cars registered 2007–2013 · Diesel

    Injector seals and other engine seals can leak on the diesels.

    At the viewing: Look for fuel or oil around the top of the engine.

    Source: Parkers: used Mercedes C-Class 2007-2014 review

  • Dual-mass flywheel (manual diesel)

    Cars registered 2007–2013 · Manual diesel

    Manual diesels can wear out their dual-mass flywheel. Above 60,000 miles, check whether it's been done.

    At the viewing: Listen for a rattle at idle and judder pulling away.

    If it needs doing: Clutch and dual-mass flywheel, about £650–£1,200. ClickMechanic

    Source: Parkers: used Mercedes C-Class 2007-2014 review

  • Harsh 7G-Tronic automatic

    Cars registered 2007–2013 · Automatic

    Later automatics can change gear harshly, and repairs are expensive.

    At the viewing: Check changes are smooth from cold and at low speed.

    If it needs doing: Gearbox sensor or solenoid, about £200–£500. ClickMechanic

    Source: Parkers: used Mercedes C-Class 2007-2014 review

  • Poor reliability record

    Cars registered 2022–2025 · All engines

    In What Car?'s survey, 43% of these C-Classes had a fault, with problems in the air con, engine, fuel system, gearbox and electrics. Many left the car undriveable.

    At the viewing: Check every warning light goes out, and test the air con and all the electrics.

    Source: What Car?: Mercedes C-Class (2021 on) reliability

  • Automatic gearbox behaviour

    Cars registered 2014–2021 · Automatic

    Some automatics shift inconsistently.

    At the viewing: Drive through every gear at different speeds. Any odd or jerky changes should be priced in or a reason to walk away.

    Source: Parkers: Mercedes C-Class (2014-2021) used review

  • Water pump and sensors (petrol)

    Cars registered 2007–2013 · Petrol

    Water pumps can leak, and air flow or crankshaft sensors cause rough running.

    At the viewing: Look for coolant leaks and check it idles smoothly.

    If it needs doing: Water pump, about £115–£375. ClickMechanic

    Source: Parkers: used Mercedes C-Class 2007-2014 review

Common Mercedes-Benz C-Class MOT failures to check

Parts flagged at MOT well above the usual rate for cars the same age, for each fuel on its own. From the DVSA’s results for every MOT done in Great Britain during 2023–2025.

Petrol

  • Ball joint

    up to 3.3× usual

    Stands out on cars registered in 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2015, 2016, 2017 and 2018.

    Rough price £60–£150 (one joint) ClickMechanic

    At the viewing: Listen for knocking over bumps and check the rubber boots behind the wheels aren't split.

  • Wheel bearings

    up to 3.5× usual

    Stands out on cars registered in 2000, 2002, 2003, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 and 2014.

    Rough price £120–£300 (one bearing) ClickMechanic

    At the viewing: Listen for a hum or growl that changes as you steer at speed.

  • Engine warning light

    up to 2.9× usual

    Stands out on cars registered in 2002, 2003, 2004, 2005, 2006, 2012, 2013, 2014, 2015, 2016 and 2017.

    Rough price £10–£80 our estimate

    At the viewing: Ask a friend to check every light while you work the switches: indicators, brake lights, fog lights and reversing lights.

  • Link ball joint covers

    up to 3.9× usual

    Stands out on cars registered in 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 and 2014.

    Rough price £60–£150 (one joint) ClickMechanic

    At the viewing: Listen for knocking over bumps and check the rubber boots behind the wheels aren't split.

  • Side repeaters

    up to 6.7× usual

    Stands out on cars registered in 1996, 1997, 1998, 1999, 2000, 2007 and 2008.

    Rough price £10–£80 our estimate

    At the viewing: Ask a friend to check every light, including brake lights and indicators, while you operate them.

  • Transmission oil leaks

    up to 4.6× usual

    Stands out on cars registered in 1995, 1996, 1997, 1998, 1999, 2001 and 2002.

    Rough price £80–£600 our estimate

    At the viewing: Look under the engine and where the car is usually parked for fresh oil. Ask whether the leak has been looked at.

Diesel

  • Ball joint

    up to 6.5× usual

    Stands out on cars registered in 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 and 2020.

    Rough price £60–£150 (one joint) ClickMechanic

    At the viewing: Listen for knocking over bumps and check the rubber boots behind the wheels aren't split.

  • Wheel bearings

    up to 5.2× usual

    Stands out on cars registered in 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 and 2014.

    Rough price £120–£300 (one bearing) ClickMechanic

    At the viewing: Listen for a hum or growl that changes as you steer at speed.

  • Rigid brake pipes

    up to 4.9× usual

    Stands out on cars registered in 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 and 2013.

    Rough price £100–£400 our estimate

    At the viewing: Ask to see underneath, or check the MOT advisories: corroded brake or fuel pipes get worse every year and fail the MOT when they do.

  • Link ball joint covers

    up to 4.7× usual

    Stands out on cars registered in 2007, 2008, 2009, 2010, 2011, 2012, 2013 and 2014.

    Rough price £60–£150 (one joint) ClickMechanic

    At the viewing: Listen for knocking over bumps and check the rubber boots behind the wheels aren't split.

  • Sub-frame

    up to 2.7× usual

    Stands out on cars registered in 2001, 2002, 2003, 2004 and 2005.

    Rough price £300–£1,000 our estimate

    At the viewing: Look underneath at the frame the suspension bolts to. Flaky rust or holes are expensive to fix.

  • Anti-roll bar bushes and joints

    up to 7× usual

    Stands out on cars registered in 2001, 2003, 2006 and 2007.

    Rough price £100–£280 (pair of drop links) Checkatrade

    At the viewing: Drive slowly over bumps and listen for a knock or rattle from the front. Worn anti-roll bar links are a cheap fix.

Hybrid

  • Ball joint

    up to 7.1× usual

    Stands out on cars registered in 2015, 2016, 2017 and 2018.

    Rough price £60–£150 (one joint) ClickMechanic

    At the viewing: Listen for knocking over bumps and check the rubber boots behind the wheels aren't split.

  • Flexible couplings

    up to 27× usual

    Stands out on cars registered in 2015, 2016 and 2017.

    Rough price £150–£1,000 our estimate

    At the viewing: Check the sills, wheel arches and underneath for rust, and look along the panels for uneven gaps or paint.

Mercedes-Benz C-Class MOT pass rate by year

Of the years since 2005 with plenty of MOT tests, the 2014 Mercedes-Benz C-Class did best (76% passed first time, 6 points above all 2014 cars) and the 2022 did worst (89%, 0 points above all 2022 cars). Older cars fail more, so compare each year with all cars registered the same year.

YearPass first timeAll cars that yearMOT tests
202394%92% +2380 (small sample)
202289%89% +04,795
202187%87% +011,663
202087%87% +030,441
201987%85% +273,990
201885%83% +284,961
201783%80% +3118,916
201681%77% +4110,990
201579%74% +5103,655
201476%70% +677,294
201371%67% +472,996
201268%64% +481,468
201168%62% +660,864
201066%60% +642,612
200964%59% +541,744
200863%57% +644,156
200761%57% +439,195
200659%56% +331,275
200558%57% +127,259
200457%57% +020,438
200358%57% +114,253
200262%58% +47,932
200162%60% +24,263
200066%61% +51,993
199969%63% +62,498
199871%65% +62,759
199770%65% +52,187
199673%66% +71,272
199572%67% +5970
199473%67% +6779

Questions to ask the seller before buying a Mercedes-Benz C-Class

Ask before you travel to see it. A seller who knows the car will have answers, and receipts.

  1. Has the fuel pump recall been done?
  2. Have there been any AdBlue or particulate filter warnings?
  3. Have the injectors or seals been replaced?
  4. Have the clutch and flywheel been replaced?
  5. Has the gearbox been serviced?
  6. Has the water pump been replaced?

Looking at a Mercedes-Benz C-Class?

Check the actual car: its own MOT history, whether it already shows these weak spots and what to ask the seller. Free, no sign-up.

Where this comes from: MOT figures are the DVSA’s anonymised results for every MOT test done in Great Britain during 2023–2025, grouped by the year each car was first registered. How many are on the road is from the Department for Transport’s vehicle licensing statistics. Known faults are from UK buying guides, in our own words, with links. How we score