I recently bought a 2007 Hyundai Elantra with 55,000 km on it. The manual says the timing belt should be changed at 72 months or 140,000 km (96,000 for hard service conditions). I'm nowhere near the limit for mileage, my car will soon be 72 months. Should I change the timing belt this year or could I safely drive it another couple of years since the mileage is so low?
If you do recommend changing it now, should I still worry about changing the water pump at the same time, considering its low mileage?
-- Paul, Dartmouth, N.S.
The timing belt won't disintegrate at midnight on your Elantra's sixth birthday. But if it breaks, you could be on the hook for a brand new engine.
"This belt should always be replaced when the manufacturer recommends," says Calvin Feist, automotive instructor at the Northern Alberta Institute of Technology (NAIT) in Edmonton. "On an interference fit engine, if the belt breaks or jumps a tooth, it will allow the valves to hit the top of the pistons and cause major engine damage."
The reinforced rubber belt is the connection between your engine's crankshaft and camshaft. http://auto.howstuffworks.com/camshaft.htm.
"It has teeth on the inside that engage gears on the crankshaft and camshaft," Feist says. "It makes sure the valves open at the correct time so the engine runs properly."
So why does Hyundai say to change it at six years or 140,000 km? Can't they just pick one?
"Timing belts are made of a rubber compound that will degrade both over time and use," said Hyundai spokesman Chad Heard in an e-mail. "It should be replaced based on months since purchase or kilometres driven – whichever comes first."
So, even if the car sat in storage for six years, the belt would still need replacing because the rubber weakens over time.
Your Elantra was scheduled to have the belt inspected at 48 months. If there had been cracks then, it should have been replaced. But other than inspections, there are no warning signs that a belt's wearing out, Feist says.
"The belt will crack and with the stress it is under it just breaks and the engine quits running," Feist says. "As long as you are strong enough to apply the brakes with no power assist and turn the steering wheel with no power steering you should not have a problem pulling the vehicle off the road."
And the water pump? It circulates engine coolant and it's driven by the timing belt. Car makers usually recommend it be replaced at the same time as the belt.
"With the low mileage that is on this vehicle, it probably doesn't need to be done," Feist says. "But, again, replacing it now before it fails is cheap insurance."
It's a good idea to follow the maintenance schedule in your car's owner's manual, Feist says. If you repeatedly drive short distances (fewer than eight km at a stretch in warm weather or 16 km when it's freezing), you should follow the schedule for hard service conditions.
"Believe it or not, these maintenance guidelines are put in place to save the consumer money and time over having to do repairs after a breakdown," he says.
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