What is the reason for the loud ticking sound in a Mercedes-Benz Smart at idle?
2 Answers
The reason for the loud ticking sound in a Mercedes-Benz Smart at idle is due to clogged fuel injectors, faulty spark plugs, etc. Dirty fuel injectors: When the fuel injectors are dirty, the engine may experience difficulties starting, reduced power, sluggish acceleration, shaking at idle, black smoke emissions, excessive exhaust emissions, and in severe cases, the engine may fail to start. The solution is to perform a no-disassembly cleaning of the fuel injectors, which can also remove carbon deposits from the combustion chamber and the top of the pistons. Poor spark plugs: When the performance of the spark plugs deteriorates, you may feel a lack of engine power while driving, jerking during rapid acceleration accompanied by a "popping" sound from the exhaust pipe, and engine shaking at idle. The solution is to have the spark plugs checked at a repair shop every 30,000 kilometers and replaced if necessary.
I've been into cars for many years, and the ticking sound from a Smart at idle is mostly due to internal engine issues. Excessive valve clearance can easily cause knocking sounds, and worn lifters or failed hydraulic compensators can also lead to this. Additionally, the ticking noise from fuel injectors during operation is particularly noticeable during cold starts, while dirty or insufficient oil can make component friction louder. Another common cause is a stretched or missing-tooth timing chain, as a loose chain can worsen the knocking. It's best to visit a professional shop as soon as possible to scan the engine data with a diagnostic tool to rule out faults and prevent further damage. Small engines like the Smart are designed compactly, making sounds more noticeable, so remember to change high-quality oil regularly.
