What Is Timing Belt And When Should You Replace it?

What is a Timing belt?

A vehicle’s timing belt (or cambelt), are extremely important for keeping internal combustion engines running. The job of the timing belt is to harmonize crankshaft and camshaft rotation, and if both are synced up properly, then your vehicle’s pistons and valves will operate correctly.

This is important because, as fuel is being ignited in the combustion chamber, your vehicle’s valves control fuel/air mixture intake and exhaust gas and push your pistons down. So, no matter if you’re driving a brand-new car or a pre-owned vehicle that’s years old, you’ll want to be certain you have a working timing belt.

The timing belt is located in front of your vehicle’s engine. It is made of a strong rubber material which includes cords that are nylon-reinforced. That way, the timing belt’s lifespan can be preserved.

While the timing belt is moving inside the motor, it is placed under a lot of stress and tends to wear out quickly for this reason. As a result, you will have to replace the timing belt on a regular basis determined by the car manufacturer.

If you let your timing belt get worn out and you don’t replace it, you can cause a lot of expensive damage to your engine.

Serpentine Belt Vs Timing Belt

If the timing belt breaks, the pistons, valves, and cylinder heads will be very damaged – even requiring a new engine in some cases. Whereas, in the event your serpentine belt breaks, you will be able to simply replace the belt in most instances, without major damage to the engine.

Serpentine BeltTiming Belt
Serpentine Belt is a thin, rubber belt that winds around several components in your engine, like a snake.Timing Belt is made of strong materials like neoprene or molded polyurethane, timing belts feature little teeth that grip components of the crankshaft.
The serpentine belt is located on the exterior of the engine block.The timing belt is located inside of your engine.
The serpentine belt is not connected directly to the engine.The timing belt is connected directly to the engine and is driven by the crankshaft.
The serpentine belt is friction drive or friction oriented.The timing belt is a direct drive. That means this belt is directly connected to the pulley of the crankshaft, which turns the camshaft.
The grooves of the serpentine belt are V-shaped. They run vertically along the inside diameter of the belt.Timing belts have horizontal grooves that are designed to fit the cogs or teeth of the crankshaft.

Symptoms of a Bad Timing Belt

When you have a bad or worn timing belt, the following symptoms can occur. If you experience any of these symptoms, have a certified auto technician or mechanic check the timing belt and replace it if necessary.

The timing belt links the camshaft to the crankshaft, which manages the pistons of the engine. As for the camshaft, it is responsible for opening and closing the valves.
Car engine with a timing belt.

1. Rough Idling of the Engine

Timing belts have teeth that grip the gears as they turn various engine parts and components. If these teeth ever fall off or become brittle, the timing belt will slip off the gears.

As soon as this happens, the teeth fall directly onto the gears and create a jolt in the motor. Worst of all, the engine stalls because the camshaft timing is incorrect.

2. Misfire of the Engine

The engine’s rate of fire could be jeopardized by the worn timing belt. If the timing belt slips off the gears and falls onto the camshaft, one of the cylinders opens and closes too early.

If this happens, the engine may misfire and the belt must be replaced immediately. Failure to replace the belt soon can cause permanent damage to the motor.

3. Smoke from the Engine

When it’s winter and cold outside, it can be difficult to tell whether the huge amounts of smoke coming out of your exhaust are actually harmless steam or water vapor. However, if you see too much smoke, which looks unusual even for the winter, it may have something to do with a timing belt problem.

The top of each cylinder has two holes that are responsible for venting the exhaust gas and letting in air. The opening and closing of these holes are synchronized with the movement of the cylinders and the rotation of the camshaft.

If you have a worn timing belt it will no longer sync, which means exhaust and air will be deflated at inappropriate times. The result is a lot of smoke coming out of your exhaust system.

4. Oil Pressure Decline

The timing belt spins the gears of the camshaft. If the timing of the belt is wrong, it can skip parts of the camshaft and break off. Some of these parts could fall into the vehicle’s oil pan, which could cause the oil pressure in the bottom of the engine to drop.

This leads to the engine failing completely. The only way to recover from this is to rebuild the entire engine.

5. Pistons or Valves That Are Broken

The worst symptom that can occur is that the timing belt is cut off or completely broken. In this case, the crankshaft rotates by itself and is not synchronized with the movement of the camshaft.

In this case, the piston comes into contact with the valves when they open. Doing so could bend the valves or damage the piston.

If you want to prevent further damage to your engine, stop the engine immediately as soon as this symptom occurs, and there is a chance that you will avoid major engine damage.

Timing Belt Safety

We hope you take your car to a timing belt service store, but even if you just look around under the hood, you need to be sure.

  • Do not begin to grab random parts under the hood, especially after you have just finished driving. Engines and engine components can get extremely hot.
  • Do not wear loose clothing or dangling jewelry when working under a hood. In addition to damaging your jewelry, they can get caught in a rotating belt or equipment and cause serious injury.
  • It is a good idea to wear gloves and eye protection, especially when working on older cars. You never know when something will break and splinters fly.

How Much Does it Cost for Timing Belt Replacement?

If your timing belt is in need of replacement, you can expect that service to cost anywhere from $300 up to $500. Because the timing belt is not easily reachable on many vehicles there is a good bit of disassembly and reassembly needed to get to the belt. Economy cars with smaller engines require less labor.

The replacement cost of a timing belt depends on the number of hours that have been spent on the replacement order. After all, in some cars, it is much more difficult to get access to some components like the timing belt.

For economical cars with small engines, the work involved should be cheaper because they are easier to disassemble. However, if you drive an SUV or truck, they have bigger engines, which means you are paying more money.

The average cost of replacing a timing belt is anywhere from $300 to $500 (more for larger cars, trucks, and SUVs). The timing belt itself typically costs less than $50, but the bulk of a timing belt job is spent on labor.

Labor costs range from $250 to $450 or more. Taxes and fees are likely to be added to these prices.

NOTE: It is often recommended to replace the water pump at the same time as it is in the same area. While a new water pump will cost a little more, you will save a lot of money on labor costs if you do it later.

When Should a Timing Belt Be Replaced?

A timing belt is one of those things that absolutely must be replaced according to the automaker’s schedule. Most often this value is between 75,000 and 100,000 miles. Please refer to the owner’s manual for the exact schedule for your vehicle.

Replacing your timing belt isn’t one of those things that you can just put off indefinitely. Eventually, the belt will tear and you can have thousands of dollars in engine damage. It’s just not worth the risk.


What is Timing Belt?

A timing belt, timing chain, or cambelt is a part of an internal combustion engine that synchronizes the rotation of the crankshaft and the camshaft so that the engine’s valves open and close at the proper times during each cylinder’s intake and exhaust strokes.

What are the Symptoms of a Bad Timing Belt?

Symptoms of a Bad Timing Belt:

  1. Rough Idling of the Engine
  2. Misfire of the Engine
  3. Smoke from the Engine
  4. Oil Pressure Decline
  5. Pistons or Valves That Are Broken

How much does it cost to replace a timing belt?

If your timing belt is in need of replacement, you can expect that service to cost anywhere from $300 up to $500. Because the timing belt is not easily reachable on many vehicles there is a good bit of disassembly and reassembly needed to get to the belt. Economy cars with smaller engines require less labor.

How do I know when my timing belt needs changing?

The most common signs that your timing belt needs to be replaced include:

  • Ticking noise from under the hood when the engine is running.
  • The engine doesn’t start.
  • The engine misfiring while driving.
  • Oil leaking from the front-side of where the motor is under the hood.
  • Hydroplaning while driving in wet weather conditions.

How long do timing belts really last?

Depending on what schedule you may read, including information distributed by the manufacturers themselves, the average life span of a timing belt is between 60,000 and 105,000 miles or after 7 to 10 years regardless of mileage.

What does a timing belt do?

The timing belt is there to make sure that the movement of the camshaft or camshafts is synchronized with the movement of the crankshaft.

Is it worth fixing a timing belt?

Although timing belts are critical, there’s no need to replace them regularly –unless explicitly recommended in your owner’s manual. Some automakers recommend changing a timing belt between 60,000 and 100,000, others don’t. Many of today’s timing belts can go 100,000 miles or more without needing to be replaced.

What happens if you don’t replace your timing belt?

If you don’t replace the timing belt at the recommended time, you could end up with total engine failure, broken or bent valves, cylinder head or camshaft damage, and piston and cylinder wall damage.

What does a worn timing belt sound like?

A failing timing belt can produce a well-known “ticking” noise that will emanate from your engine. This ticking noise can also be a sign of low oil pressure within your engine, if you check your oil and your level is within a normal range, consult your mechanic to inspect your timing belt.

Can I change timing belt myself?

But if you are and you enjoy doing your own repairs or restorations then it’s something you can do yourself, and save on some big repair bills in the process. We’ll walk you through the process of replacing a timing belt and water pump step by step, starting with the tools you’ll need.

What happens if timing belt breaks while driving?

When the timing belt breaks, the crankshaft will continue to spin at 1000 rotations per minute, while the camshaft will stop turning. As a result, the pistons will continue to rise and fall in their cylinders, but they will strike closed valves.

Why Is a Timing Belt Change Such an Expensive Service?

The timing belt itself isn’t an expensive part. The time and labor are what make it so expensive. To get to the timing belt, the engine needs to be disassembled.

What causes timing belt to break?

With the heat and friction inside the engine, the rubber material will become worn with age and miles. Rubber teeth may wear down and no longer be able to grip the gears. This often results in a slip of the timing belt and potential damage to the engine. The timing belt may also begin to crack under stress.

Can A Bad Timing Belt Affect Shifting?

Misfires or Runs Roughly When your timing belt wears out, it can cause engine misfires. As the timing belt controls the movement of the pistons within the engine, if it is worn or lost, they will move erratically.

How do you check timing belt?

Look for any contaminants that could eat away at the belt or cause it to slip. Also, look for cracks in the belt. If the belt has many cracks in it, this can indicate that the belt is old or has dried out. Next, inspect the underside of the belt and verify that all the teeth are in good condition.