Can Timing Belt Affect Gas Mileage? Let’s Find Out!

Timing belts can affect gas mileage. Worn out timing belt affects the car’s power generation and transmission efficiency, which reduces its gas mileage. The best action to take in this circumstance is to replace the worn-out belt. Moreover, if the parts are not correctly adjusted to the new timing belt during replacement, it may increase fuel usage. 

So ultimately, can timing belts affect gas mileage? Yes, but how can you identify whether a belt is actually faulty and take it off? Keep reading to find out.

Can Timing Belt Affect Gas Mileage?

Yes, the timing belt can affect gas mileage, but it depends on several things. The cambelt or timing belt is critical to your car’s performance. A good timing belt will improve power transmission efficiency and reduce noise.

If the belt is worn out, it will affect the car’s power generations and transmission efficiency. The timing belt synchronises the rotation of the crankshaft and camshaft and this synchronisation controls the intake and exhaust valves.

While replacing the timing belt, if the camshaft and crankshaft are not adequately adjusted to the new belt, it increases engine fuel consumption. Hence ultimately affecting the gas mileage.

Does the Timing Chain Affect Gas Mileage?

Similar to the timing belt, the timing chain can also affect gas mileage in some cases. A timing belt and timing chain are both used for the same reason. However, timing chains tend to be noisy. The friction loss with chains is also too much. The timing chain can sustain much longer because they are made from metal. 

Signs of A Bad Timing Belt 

Before you rule your timing belt as faulty or bad, first check whether it is showing these signs or not-

Check Engine Light: A bad timing belt will turn the Check Engine Light on. This light usually turns on if any part of the engine is malfunctioning. So, when the timing belt causes engine malfunction, this light turns on. 

Ticking sound: When the timing belt begins to wear out, it sometimes makes a ticking noise.

Engine Misfire & Rough idling: If the timing belt is worn out, the camshaft timing usually gets off. This can result in improper fuel combustion, leading  to engine misfiring. And, this misfiring eventually results in rough idling.

Engine Won’t Start: The timing belt synchronises the rotation of the crankshaft and camshaft. So, if the belt is completely broken, your engine can’t function and will not start at all.

When Should You Change the Timing Belt? 

Timing belts need to be replaced after a set number of miles, which can be between 60,000 and 100,000. Alternately, if you’re thinking about years, you should replace it between 4-6 years. 

Regardless of the number of miles driven, some manufacturers advise changing the belt as it ages. (1) Depending on the model of your car, this time may vary. 

The car’s manual will have precise timing belt replacement information for your particular vehicle. If not, ask us in the comments box, and we’ll be happy to assist you.

What Causes the Timing Belt to Wear Out Faster? 

Timing belts should last for 4-6 years or 60,000-100,000 miles. However, they can prematurely wear out due to the following reasons.

Oil Leaks

When there is an oil leak, it can get in between the teeth of the belt. Additionally, the oil in timing belts can collect dirt and debris. This can lead to belt slippage resulting in premature belt wear.;

Water Leaks

Water leaks affect your timing belt just like oil leaks. Because of the water leak, the teeth of the belt can get damaged, and the belt might slip off and damage the engine eventually. These effects can get severe with coolant leaks. 

Improper Belt Tension

Timing belt tension can sometimes be too tight or too loose. Too tight belt tension can cause the belt to stretch out faster, on the other hand, loose belts are prone to slippage. Both of these lead to premature belt wear. 


If the belt is misaligned it can easily get  in contact with the belt cover or other engine components. This contact can wear out the belt faster. Moreover, the misaligned belt can cause engine misfiring and reduce overall performance.


Improper belt tension, misaligned timing belt, water leaks, and other reasons can cause the timing belt to wear out quickly. 
what Causes the Timing Belt to Wear Out Faster Infographic

How To Change the Timing Belt?

It is recommended to replace the timing belt and water pump together. But why do you need to change the water pump while changing the timing belt?

The water pump’s location is in the belt’s drive line in new car models and many contemporary engines. The water pump may not be broken or leaking, but it could malfunction when the new belt is used. 

So, replacing the water pump simultaneously with the timing belt becomes crucial. Moreover, the labor cost for replacing the pump is negligible compared to the belt change. 

Some models, however, will require additional labor due to the longer time required to remove the pump.

Now, let’s get into the real business.

It takes some engine knowledge to replace a timing belt and water pump. If you’re not used to this, we’d suggest leaving it to the experts. However, if you love making your own restorations and know the engine well, then just follow these steps carefully.

Required Tools to Replace Timing Belt & Water Pump

To replace the timing belt, you will require the following tools.

1. Socket wrench set

2. Screw drivers

3. Rubber gloves

4. New Timing belt

5. New water pump

6. Coolant

7. Drain pan

8. Ratchet

9. Gasket & Sealant

Before starting with the following procedure make sure to first disconnect the negative battery cable from the battery terminal. This will ensure that there’s no possibility of any electrical accidents.

Step 1: Remove Serpentine Belt

The serpentine belt is mounted on top of the timing belt cover. So you need to remove the serpentine belt first. Then you can move on to the timing belt cover.

Remove the serpentine tensioner screw using a socket wrench. Then, pull out the serpentine belt slowly. Finally, check if there are any other pulleys on the belt cover. This varies depending on the car model. Remove them as well before you move on to the belt cover.

Step 2: Remove Timing Cover

The timing cover protects the timing belt and water pump. Use a socket wrench to remove the screws that are holding the cover. Use a marker to mark these screws and their respective places so it gets easier to put them back.

Step 3: Loose Belt Tension & Remove Old Timing Belt

With the timing belt now accessible, you need to loosen its tension first before you can remove it. Use a ratchet on the tensioner pulley and turn it counterclockwise. This will loosen the timing belt. Now slowly remove the timing belt. 

Step 4: Remove Water Pump

The next step is to remove the water pump. First, put a drain pan underneath the water pump. Remove the mounting bolts using a wrench that holds the water pump. You also need to remove the clamps from the hose. This hose circulates the coolant through the water pump.

Step 5: Install a New Water Pump & Refill Coolant  Reservoir

You need to replace the old gasket before installing the new water pump. Because it gets damaged when the water pump is removed. Scrape out the old gasket using a flat-head screwdriver and replace it with a new one.

Before putting the water pump on, apply an even bead of sealant on the edge. Next, tighten the screws to the manufacturer’s specified torque. Don’t forget to reattach the hose before filling the reservoir tank with fresh coolant.

Step 6:Install New Timing Belt 

Next, you need to install the timing belt with the crankshaft and camshaft. Look for the timing marks on the crankshaft and camshaft and align them accordingly while installing the belt.

Ensure the pulley alignment is maintained while doing this. Follow the picture above to clearly understand the placement.

For longevity, you must clean and maintain the timing belt after installing it. Speaking of cleaning it, note that you shouldn’t clean the timing belt with brake cleaner and here’s why.

Step 7: Adjust Timing Belt Tension

After installing the timing belt you need to adjust the belt tension according to your car’s manufacturer’s recommendation.

Rotate the spring-loaded tensioner pulley bolt clockwise to tighten the belt. Keep rotating till the belt is tightened according to the manufacturer’s recommended tension. To check the tension using a tension gauge or a sonic tensioner, you can follow the video below:

Step 8: Re-check the Tension and Coolant Level

Now, reconnect the negative battery cable and run the engine for 5 to 10 minutes with the coolant reservoir cap off. This will eliminate any air in the cooling system. After shutting the engine off, check the coolant level and top it off if necessary.

Also, check the belt tension again. If you find any mismatch in the tension, follow step 7 and adjust accordingly.

Step 9: Reinstall the Belt Cover &  the Serpentine Belt

Now, replace the timing belt cover and other accessories in their respective places. Follow the marks you made in step 2 to put these accessories in their places

Please keep in mind that this is only a guideline. It’s always better to contact a mechanic if there’s any difficulty while doing this.

What’s the Probable Cost of Changing the Timing Belt and Water pump?

The price to replace a water pump and timing belt can vary depending on your car. You should budget between $360 and $730 for the work if you take it to a garage. If you do the job yourself, you can get a timing belt and water pump set for roughly $50 to $180.


What’s the Difference Between Cambelt and Timing Belt?

There’s no difference between a cambelt and a timing belt. Despite having different names, they are the same belt made of nylon and butyl.  Depending on the vehicle, they come in different sizes and shapes. To avoid wear and tear, you must inspect your timing belt periodically, just like any other car part.

Can You Drive Without A Timing Belt?

No, you cannot drive without a timing belt at all. The car will immediately stall if the belt snaps while you are driving. Moreover, you risk severe damage to your engine if you intend to drive with a worn-out timing belt. Most manufacturers advise replacing the timing belt every 60,000 to 100,000 miles to prevent unwanted accidents.

What Happens if the Timing Belt Snaps While the Engine is Running?

The valve springs will force all the valves shut if the belt snaps. No matter how fast the car goes, the crankshaft will keep driving the pistons up and down for a while. It will soon hit the valves due to sheer inertia in the interference engine. A non-interference engine, however, avoids this effect due to the space between the valves and the pistons. 


Well, you now have the answer to can timing belt affect gas mileage question. Although changing the timing belt is easy with the steps we have mentioned, we recommend consulting with a mechanic before starting the process. 

Always check for any oil or water leaks before going on a drive to ensure the utmost safety of you and your car. If there are any warning signs of a broken timing belt, don’t drive the car without fixing the problem.

Until next time, good luck!

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Aaron Byrne

Hi, Aaron Byrne here. I'm an expert automotive mechanic with 10 years of experience. I work on engine parts especially timing belts for their repair, maintenance, and replacement.

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Talha Atta

Talha Atta, a Mechanical Engineer and experienced technical content writer and editor at with a passion for the automotive industry.