Mercedes-Benz C-класа pre-purchase inspection

W204 and W205, 2007–2021

The C-Class is comfortable and well equipped, but the automatic gearbox and some diesels need a careful check.

Pre-purchase inspection report

Audi A6 3.0 TDI quattro · 2014

248,000 km · VIN WAUZZZ4G1EN•••••• · 08.09.2026

Sample report

We don't recommend buying at this price

Expected repairs €3,800–5,500: the timing chains and the gearbox clutches are at the end of their life.

7 sections · 35 photos · 2 problems, 4 to monitor

EngineTiming chain rattle on cold start 8Problem

What we found: On a cold start there is a metallic rattle from the back of the engine for the first 2–3 seconds. Diagnostics show camshaft-to-crankshaft deviation close to the limit.
What it means: The timing chains are stretched — a known issue on the 3.0 TDI past 200,000 km. Left alone, a chain can jump a tooth and seriously damage the engine.
What to do: Replace the chains, tensioners and guides (engine out). Don't buy without a discount that covers the repair.Approx.: €2,200–3,000.

Gearbox (S tronic)Harsh 1→2 shift when cold, worn clutches 5Problem

What we found: When cold, the 1st-to-2nd shift is harsh with a slight jolt. Clutch adaptation values are at 88% and 91% of the limit.
What it means: The gearbox clutches are heavily worn. It will soon start to slip and log faults, and later go into limp mode.
What to do: Replace the dual clutch and adapt. Check whether the gearbox oil was ever changed (no record in the history).Approx.: €1,500–2,300.

Body & paintFront right door and wing repainted 10Monitor

What we found: Paint thickness is 240–310 µm on the front right door and wing versus 105–130 µm elsewhere. Panel gaps are even; no signs of straightening inside.
What it means: Both panels were repainted — most likely after a minor knock or scratch. No sign of structural damage.
What to do: Not a deal-breaker on its own, but ask the seller about it and use it when negotiating.

DiagnosticsActive swirl-flap fault 2Monitor

What we found: Active fault P2015 — intake manifold swirl-flap position sensor. The warning light is not on at the moment.
What it means: The swirl-flap mechanism is worn — common on this engine. It reduces pulling power low down and can trigger limp mode.
What to do: Repair the mechanism or replace the intake manifold.Approx.: €300–650.

Suspension & brakesWorn front control-arm bushes 7Monitor

What we found: The upper front control-arm bushes are cracked; there is a knock over bumps. Brakes are at 50% front and 70% rear.
What it means: Normal wear for the mileage, but it affects handling and tyre wear.
What to do: Replace the upper control arms (or bushes) and do an alignment.Approx.: €350–500.

Road testConfirms the gearbox and suspension findingsMonitor

What we found: During an 18 km road test the gearbox shifts harshly when cold and there is a front knock over bumps.
What it means: Confirms the diagnostic readings and the lift inspection.
What to do: See the Gearbox and Suspension sections.

VIN & documentsVIN matches the registration 3OK

What we checked

Page 1 of 7 PDF · 35 photos

Typical weak spots of the Mercedes-Benz C-класа

1
7G-TRONIC control plate
Why it matters: The gearbox speed sensors fail — harsh shifts and limp mode.
How we check: Shift quality, gearbox module faults.
2
Injectors on early OM651
Why it matters: The piezo injectors of the first years have a known issue and were subject to a service campaign.
How we check: Injector corrections, campaign history.
3
Corrosion
Why it matters: Wheel arches, sills and lower door edges on the W204.
How we check: Lift inspection and paint measurement.

We check everything else too — body, diagnostics, suspension, documents and a road test. The full list of checks

The listing link and your phone are enough.

Up to 30 km from our workshop: All of Sofia, Bankya, Bozhurishte, Kostinbrod, Novi Iskar, Elin Pelin, Gorna Malina.