If you have a bad or worn out timing belt, the following are symptoms that may occur. Once you experience one or more of these symptoms, have a certified auto technician or mechanic inspect the timing belt and then replace it if necessary.
#1 – Rough Idling of the Engine
There are teeth on timing belts which grip gears as they’re rotating various engine parts and components. If these teeth ever start falling off or become brittle, the timing belt will start to slip away from the gears.
Once this happens, the teeth will fall directly onto the gears and form a jolt in the engine. Worst of all, the engine will begin to stall because the camshaft timing is off.
#2 – Misfire of the Engine
The fire rate of the engine could be jeopardized from the timing belt being worn out. If the timing belt were to slip away from the gears and fall onto the camshaft, one of the cylinders will open and close too soon.
If that happens, an engine misfire could occur which means the belt needs to be replaced right away. If you don’t replace the belt soon, the engine could be permanently damaged.
#3 – Smoke from the Engine
If it is wintertime and cold outside, it may be hard to tell if the vast amounts of smoke coming from your tailpipe are actually harmless steam or water vapor. But if you see too much smoke that looks unusual even for the winter, then it might have to do with a timing belt problem.
#4 – Oil Pressure Decline
The timing belt spins the gears of the camshaft. If the timing of the belt is off, it can skip and break off pieces of the camshaft. Some of these pieces might fall into the vehicle’s oil pan, resulting in the oil pressure to drop in the bottom of the engine.
This will cause the engine to fail altogether. The only way to recover from this is to rebuild the entire motor.
#5 – Pistons or Valves That Are Broken
The worst symptom you can experience is having the timing belt cut off or broken completely. If this is the case, the crankshaft will end up turning on its own and not be in sync with the motion of the camshaft.
Once this happens, the piston will come in contact with the valves as they open. This could end up bending the valves or damaging the piston.
NOTE: It’s often recommended to replace the water pump at the same time while in there since it’s in the same area. It may cost a bit more for a new water pump but you’ll save a lot of money on labor costs if you were to do it later on.