Mercedes-Benz SLK 32 AMG
Three-valve V6 with individual ignition coils. Smooth and strong. Typical weak points: crankcase breather and intake manifold flaps. High mileages achievable.
SLK 32 AMG: Supercharged Legend
260 kW AMG supercharged V6 in the light R170 — the SLK 32 AMG is a legend. Brutally quick for the weight, AMG directness, open sound. A rare icon.
Engine Weaknesses 7
The camshaft adjuster solenoid on the M112 develops a leak and draws oil by capillary action into the wiring harness. Oil can migrate as far as the engine ECU and destroy it.
Symptoms: Cold-start rattling that disappears after 1–2 seconds, camshaft adjuster fault code, oil traces at wiring connector, later ECU faults
The vacuum hose for the variable intake manifold on the M112 becomes brittle and breaks. The swirl flaps stick. The hose is not available individually — the entire intake manifold is needed.
Symptoms: Power drop, slight hesitation at part throttle, engine runs but without full power
On the M112 V6 the valve cover gaskets become porous over time. Especially the rubber seals on the front cover between the timing cover and engine block fail on virtually all high-mileage M112 engines.
Symptoms: Oil spots on the floor, oil smell after driving, oily engine bay, dropping oil level
The plastic linkage of the variable intake manifold in the M112 typically breaks around 150,000 km. The actuator and tumble flaps freeze in one position — according to forum reports, all M112 engines are eventually affected.
Symptoms: Engine enters limp mode, power drop at higher revs, intake flap fault code, stumbling on acceleration
The M112 V6 has two spark plugs per cylinder sharing a dual-output ignition coil. Neglected plugs prematurely destroy the coils.
Symptoms: Rough idle, individual cylinder misfires, CEL, power loss at cold start
The crankcase ventilation membrane in the M112 wears and causes elevated oil consumption and engine sweating. Engine power can also drop due to false air ingestion.
Symptoms: Oil consumption above 1 L/5,000 km, light oil mist in engine bay, smoke from exhaust
The thermostat on the M112 V6 can stick in the open position. Engine only reaches 70–80°C instead of the target 87°C. Result: increased fuel consumption, poor heater output.
Symptoms: Engine doesn't warm up properly, heater stays cold, increased fuel consumption, temperature gauge permanently low
Vehicle Weaknesses 9
Vario roof hydraulic cylinders develop leaks and the roof no longer opens or closes fully. Opening time over 28 seconds indicates hydraulic loss. Specialist repair required.
The Valeo transmission oil cooler develops leaks and can direct coolant into the gearbox. Gearbox connector contacts corrode and destroy the TCU. Transmission oil change every 60,000-80,000 km strongly recommended.
O-rings and rod seals wear in temperature extremes, particularly in summer. Complete replacement at Mercedes over 8,000 EUR; seal kit repair significantly cheaper.
Rust forms at contact points between bodywork and bumpers, around the boot lock and at wheel arches. Underbody diagonal braces rust without regular maintenance.
Front control arm bushes and camber struts typically wear with age. Poor handling and imprecise steering result. Dampers and springs are also MOT candidates.
The O-ring on the TCU connector becomes brittle, oil enters the connector and damages the control unit. The gearbox shifts into 3rd-gear limp mode. Restarting temporarily clears limp mode.
The four water drainage channels block with leaves and dirt. The thin-walled original hoses kink at the pass-through point. Boot lid seal replacement approximately 500 EUR per side.
Roof frame and door seals become porous; water enters the door cards. Damp interior encourages rust in the underbody. Seat squeaking and poor door closure are common.
Three microswitches become dirty or fail. From Mercedes approximately 32 EUR each; as industrial components approximately 2.30 EUR. Incorrect lubrication accelerates wear.