(Updated on December 5, 2019)
The function of the timing belt is to rotate the crankshaft and camshaft of the engine and to make sure they’re synchronized in their rotation. This synchronization allows the cylinders to fire at the right time and keep the engine running the way it is supposed to.
If the timing belt were to break or become worn out, then it would limit the functionality of the engine or cause it to not run at all. Usually extensive engine damage occurs with a broken timing belt.
Since the timing belt in the engine is constantly subjected to stress and harsh conditions, it’s critical to follow the car manufacturer’s recommended timing belt change interval.
Top 5 Bad Timing Belt Symptoms
When you have a worn, cracked, torn, or broken timing belt, there will be some obvious signs that will show up. Below are five of the most common symptoms of a bad timing belt that you should watch out for.
As soon as you suspect a failing timing belt, you should have your car towed to a repair shop to avoid the chance of completely breaking the belt (if it hasn’t already fallen off its pulley).
1) Engine Misfire
Since a bad timing belt can put a damper on the firing rate of the engine, it will likely cause the engine to misfire. This will happen if a worn-out timing belt were to slip off its pulley and fall onto the camshaft drive.
Then the timing of when the cylinder opens and closes would be thrown off, which would cause a misfire for sure. If it doesn’t get replaced fast, the engine will suffer irreversible damage.
2) Rough Idling
Are you experiencing rough idling from your engine? If so, then you may be experiencing lots of jerkiness and shakiness as you’re behind the wheel. This is one of the main symptoms of a faulty timing belt.
If your timing belt has worn out or missing teeth, then it will likely slip out of its position and fall onto the other gears. The timing will then be off on the camshaft, resulting in the engine stalling.
3) Broken Valves or Pistons
Whenever there is no synchronization between the rotating crankshaft and camshaft, the piston could get damaged and end up bending the valves as it comes in contact with them. The most common reason for this happening is when the timing belt totally snaps apart.
The only thing you can do at this point is to install a new timing belt before the engine gets seriously damaged (if that hasn’t already occurred).
4) Low Oil Pressure
As a timing belt starts to get excessive wear, pieces of its teeth will come loose and break off into the oil pan of the vehicle. This will cause a significant drop in the oil pressure of the engine.
If not enough lubrication gets to the internals of the engine, complete engine failure may occur. At that point, rebuilding or replacing the engine is the only fix.
5) Ticking Sound
The timing belt is connected to lots of pulleys and is surrounded by a lot of other components. If the timing belt were to get worn out, it will start to become loose and possibly make a ticking sound as it continues to wear out.
The sound will remain there until it’s replaced or the timing belt gets so worn that it breaks apart.
Read also: Timing Belt vs Serpentine Belt
Timing Belt Replacement Cost
When you realize that it’s time to replace your timing belt, the total cost will likely put a dent in your wallet. Because a timing belt job usually includes replacing the water pump, belt tensioner, and idler rollers (in addition to the belt itself), the total replacement cost will be between $300 and $1,000 on average.
The price will be on the lower end for small vehicles and on the upper end for larger trucks and SUVs. Expect to pay more at a dealership vs a good independent mechanic.
While the timing belt itself will only cost about $30 to $60, additional parts like the water pump will add another $200 or so. Timing belt kits which include everything needed for the job are most commonly purchased.
The biggest expense will the for the labor costs since replacing a timing belt can take a few hours. For this reason, plan on about $250 to $700 just in labor costs. Unless you have at least a moderate amount of auto repair experience, you shouldn’t try to replace a timing belt yourself. This is one of those jobs you should let a pro handle.