mhd belt, timing chain, exhaust and automated gearbox on the smart fortwo 451

Engine / equipment

smart fortwo 451 (1.0 Mitsubishi, mhd and 0.8 cdi)

Period mentioned

2007–2014

Symptoms

A chirp that changes with speed and a broken auxiliary belt (mhd); metallic rattle after a cold start; a rusty exhaust; a tailgate that will not open; oil sludge and leaks; harsh shifts from the automated gearbox.

Possible cause described

On mhd models (from 2008) the belt tends to break and damage nearby parts. On short trips the engine does not warm up and sludge forms; the chain can stretch if oil changes are neglected. Before the 2010 facelift the catalytic converter and silencer are one part, which is more expensive to replace.

Check for the garage

Listen for belt chirp and replace it in time; change the oil every 20,000 km or every year; check the exhaust and tailgate lock; read the gearbox adaptation.

Cost cited in the source

No verified estimate; ask the garage for a quote.A rough figure from the original database, not an up-to-date quote.

Sources from the original database