What does a timing belt do?
The timing belt, or cambelt, is a vital engine component with a key role to play in keeping your motor running smoothly. It ensures the top and bottom halves of your engine rotate precisely in time with each other.
Essentially, this ribbed rubber belt with teeth synchronises the crankshaft and camshaft’s rotation. It controls the sequencing and timing of the opening and closing of the valves on the cylinders in your engine to provide the right combustion.
Camshafts, made up of the main journals, the lobes (or bulges) and the ends, control the valves in the cylinder head. A rocker head takes the spinning motion of an overhead camshaft and turns it into the movement that opens and closes the valves.
Timing chains essentially perform the same function as cambelts but may be slightly noisier. The chains generally last as long as the vehicle (and generally require less frequent replacing), although the plastic guides they run over may not.
How often should a timing belt need replacing?
There’s no ‘one size fits all’ approach for how often to replace yours—a lot depends on your motor’s age and condition.
There’s also huge variation between manufacturers and different engines. So you might need a new belt after 4 years, or 6, or after driving 40,000 or 100,000 miles. Consult your car’s manual—most manufacturers’ recommendations are based on time passed or miles driven, depending on which elapses first.
However, we’d always suggest treating these recommendations as a maximum, and erring on the side of caution.
The law, vehicle regulations, and your MOT
The timing belt will not be examined at your car’s MOT, but the associated issues of running a car with a faulty timing belt can lead to severe engine damage, which can.
What causes a timing belt to stop working correctly?
Like most car parts, your timing belt will wear out eventually due to cracking, snapping or tearing. Timing belts are also unpredictable, with few warning signs of damage. (Although starting issues and noise may offer clues.) Driving your car infrequently, oil leaks and temperature changes, among other factors, can all play their part.
Symptoms of a malfunctioning timing belt
You hear unusual noises coming from the engine
If a grinding or squeaking noise is being emitted from your engine, it could be a malfunctioning timing belt.
The car won’t start
If your timing belt has broken, this can cause problems with your engine that lead to the vehicle not starting.
Smart is a German automotive brand, established 25 years ago in 1994.
The company is a division of the automotive corporation Daimler AG and operated under the ownership of Mercedes-Benz.
How popular is Smart in the United Kingdom?
Smart isnt’ the most popular brand in the UK, most likely due to appealing primarily to parking-challenged city-dwellers; there are only 96k of their vehicles on the roads of the UK today.
Showing steady growth, however, since their introduction to the UK market in 2003, the trend would suggest that we’re likely to see more of these eccentric looking tiny cars as time goes by.
Smart: Quirky little microcars and subcompacts
Owned by Mercedes-Benz, Smart cars fit into the market you’d expect on first glance. They’re a fun and funky little city car; they’re solid, middle of the road machines, designed to be as versatile as they look.
A Smart car will never fool anyone that it’s a hi-end, luxury vehicle. There’s plenty of glossy plastic and groovy fabrics, yet in the cockpit, you’ll find up-to-the-minute touchscreen media options at the controls. They do come at an inflated price for the small city car market, but by nature of their unique design—there’s nothing quite like them.
Smart cars are cheap to run—but not so cheap to buy
Your Smart ForFour will be more expensive by comparison than its rivals: the Fiat 500, Skoda Citigo, Kia Picanto or Hyundai i10—yet it’s rather hard to pitch the Fortwo against anything because there isn’t anything on the market quite so small. Only the Renault Twizy comes to mind, and that’s barely a car at all.
Once you’ve got one though, your Smart car will cost next to nothing to run with their tiny wheels and low weight. The electric models perform even better with a fuel equivalent of 87mpg.
Smart’s reliability and reputation
Smart didn’t feature as one of the brands in the What Car? Reliability Survey in 2018 that we’ve been using to draw comparisons of reliability against other marques—but checking the user reviews gathered by the AA it would appear that most owners have very few problems and that their reliability scores are generally high.
Recent Smart recalls and reliability issues
Various recalls have been made on Smart models throughout their motoring history. The following are a list of the most recent in the UK and Europe.
14/10/2017 – Smart ForTwo, Smart ForFour (2017)
The strength of the left front steering knuckle may be insufficient
29/09/2017 – Smart ForTwo, Smart ForFour (2014–2015)
As a result of the weakening of the braking rope wrench adjustment knob, the hand brake lever travel could be prolonged gradually
24/06/2016 – Smart ForFour (2014–2015)
The anchorage for the rear seat backrest may not be sufficiently resistant
10/06/2016 – Smart ForTwo (2014–2015)
At high vehicle speed, combined with strong wind, the plastic front service hatch can detach from the vehicle and fall into traffic
05/06/2015 – Smart ForTwo (2014)
The steering mechanism screws used for some vehicles may break
All recall information sourced from gov.co.uk data.