Buying checklist Mercedes-Benz E-Klasse W123

Much becomes clear before you travel. If papers are missing without a good reason, that is already a price argument, or a reason to cancel.

• Registration document present, the Stammnummer matches the vehicle
• Latest MFK (periodic vehicle inspection): date, any conditions, and veteran entryVeteran status is tied to conditions (condition, mileage). Gaining it later can be expensive.Veteran status explained
• Look at the service book, invoices and restoration recordsPhotographs of a restoration are worth more than the words "just done".History and papers
• Matching Numbers: check engine and chassis numbers against the papersHistory and papers
• Are the number of previous owners and the location history plausible? (import, periods standing)Importing into Switzerland
• Read the value estimate and the weak points of the series beforehandBoth are in the buying guide for that series.

Sheet metal is the dearest item on a classic. Take your time, bring a torch and a magnet, and be twice as wary of fresh underseal.

• Rust in the usual places: wheel arches, sills, jacking points, window frames
• Inspect the underside. Fresh, thick underseal can hide rust
• Are the panel gaps even all round? Uneven gaps point to an accident or a poor repair
• Paint: colour differences, runs, masking edges, signs of a resprayA paint-thickness gauge costs little and shows filler at once.
• Doors, bonnets and lids close cleanly, and the doors do not sag
• Chrome, trim and rubber seals: condition and completenessA replacement looks trivial, but on a rare model it is often expensive or unavailable.
• Are the drains clear? (scuttle, sunroof, boot, fuel filler)

See the engine cold. A warmed engine hides starting trouble, rattles and smoke, so arrange the visit with the car cold.

• Cold start: does the engine fire willingly, and how is the idle in the first minutes?
• Check the oil level and colour, and look at the coolantStreaks in the coolant or pale foam on the oil cap point to the head gasket.
• Leaks at the engine, gearbox and differential (look from below)A light sweat is normal on an old engine. Drips are not.
• Exhaust smoke: blue = oil, white (persistent) = head gasket, black = mixture
• Clutch: bite point, judder, slip under load
• All gears including reverse; synchromesh on the downchange
• Ask about the service state of the expensive items: timing belt or chain, valve clearances, carburettor overhaul

Unspectacular, but it matters for safety, and the MFK is unforgiving. Electrics are the most often underestimated cost on a classic.

• Dampers, bushes and steering: play, knocks, worn joints
• Brake pipes and hoses: rust, porosity, age
• Tyres: check the DOT age (older than 8–10 years: replace), is the wear even?Wear on one side gives away geometry or accident damage.Tyres on a classic
• Try every electrical consumer: lights, indicators, wipers, instruments, heater and fan
• Look at the loom: bodges, flying fuses, added equipment
• Are the battery tray and earth points free of corrosion?

The interior often gives away the true mileage better than the odometer, and damp in the footwell is a warning of hidden rust.

• Seats: upholstery, bolsters, seams. Does the wear match the stated mileage?
• Dashboard: cracks (sun damage), and whether every instrument works
• Lift the carpets: damp or rust on the floorpan?A musty smell as you get in is a clear sign of water getting in.
• Headlining and, on a convertible, the hood: condition, mechanism, waterproofing
• Originality: wheel, radio, gear lever, pedal rubbers. Are changes documented and reversible?

No purchase without a drive, even if the seller hesitates. Drive it yourself, at least 20 to 30 minutes, with a cold start.

• Experience the cold start and the first minutes yourself (do not let it be warmed up)
• Tracking: on a straight, safe road, does the car pull to one side?
• Brakes: pedal feel, pulling to one side, judder under harder braking
• Listen on purpose: suspension knocks, gearbox whine, wheel-bearing drone in corners
• Watch temperature and oil pressure for the whole drive
• After the drive, look underneath again: fresh drips at the engine, gearbox or differential?

The critical points of the W123, in addition to the shared inspection catalogue. The car has a reputation for being indestructible – that is exactly why many examples hide decades of postponed maintenance behind a spotless first impression.

• Tap the jacking points and the sills, and check the inner sill with a mirror or an endoscope – the inner sill is the direct continuation of the floor panelA proper sill repair costs several thousand francs per side; cheaply patched sills rust through again within a few years.
• Check the rear wheel arches, the front wing edges and the rear valance for rust and filler – bring a magnet or a paint-thickness gauge
• Check the battery tray in the engine bay and the drains at the windscreen, sunroof and doors – blocked drains are rust source number one
• Check the sunroof frame and the C-pillars from inside (headlining, seals): bubbles under the trim strips almost always mean rust-through
• Front axle: test the ball joints and tie-rod ends over bumps, and check steering play in the straight-ahead position – more than two fingers of play at the wheel is a warningOverhaul or replacement of the recirculating-ball steering runs to four figures; steering play is readily talked down as “normal for its age”.
• Diesel (OM615/616/617): experience the cold start yourself – long preheating and heavy knocking point to tired prechambers and loss of compression; check for oil leaks at the engine and the injection pump
• Diesel: when you pull the key, the engine must stop at once and cleanly – running on reveals a leak in the vacuum system, which also supplies the central locking and the headlamp levelling
• Petrol (M102/M110): watch the cold start and warm-up, and check the cooling system and the thermoswitch; on the injected engines (230 E/280 E/280 CE) check the fuel-pump relay, the lines and the tank for ageingThe W123 rarely overheats dramatically; it suffers quietly – consequential damage to the cylinder head and head gasket quickly costs more than half the purchase price.
• Carburettor models (200/230 with Stromberg): test the automatic choke, warm-up and transition – a worn-out carburettor only runs cleanly again after an expensive overhaul
• Automatic: check the shift behaviour at operating temperature – soft but noticeable is normal; a hard clunk, slip or delayed shifts are not
• Interior: check the MB-Tex and cloth upholstery for splits, the seat springs for sagging, and the Zebrano wood and dashboard for cracksCrack-free original dashboards are sought-after collector parts and quickly cost four figures used.
• Make the history and the mileage plausible: spot a taxi past (traces of Hellelfenbein paint under the door seals, holes in the roof or dashboard, wear that does not match the odometer)
• Check the data card and matching numbers: compare engine and chassis numbers and the colour and equipment codes with the Mercedes data card – originality drives the value

The most important step comes after the visit: judge it soberly instead of deciding in love.

• Judge the condition grade honestly (1–5). If in doubt, half a grade worseThe grades are explained in the knowledge article on condition grades.Condition grades explained
• Compare the price with the series estimate, and note the faults as a negotiating list
• If you are serious: arrange a short independent appraisal, or a second visit with a specialistAn appraisal costs a few hundred francs. Missed sheet-metal damage costs several times that.Appraisal before buying
• Do not rush: a serious seller allows time to think