Home Diagnosis and TroubleshootingEngine Problems Timing Belt – All The Ways To Diagnose A Bad Belt

Timing Belt – All The Ways To Diagnose A Bad Belt

by Jordan Harris
Timing Belt

Have you experienced some weird noises from behind the timing belt cover and you are asking yourself if you are suffering from timing belt symptoms and you want to learn the timing belt replacement cost? If this is the case, then you are at the right place because there will be a lot to cover on this topic where we will dive deep into this problem.

Having a problem like this is a dangerous thing. You just don’t want to have issues with this belt. Why I’m saying this? Well, this is the case because this is a really important piece of your engine. Meaning that without this important belt, your engine will potentially fail completely and you will end up with scrap metal (at least you can learn the Scion TC catalytic converter scrap price).

This is the case because the damage will be created inside of the engine. The valves and pistons will collide and this will cause some really bad damage to your engine. A really expensive nightmare is these types of failures. That’s why the health of this component is key if you don’t want to end up with something really broken. And here we are going to help you out.

First, we will learn what is a timing belt in general. Then we will cover the serpentine vs timing belt and the timing belt symptoms. We will list all of them. Then we will learn more about the replacement and the timing belt replacement cost. So, if you want to learn more about this. Follow along till the end.

What Is A Timing Belt

Now before we dive deeper into this topic of timing belt replacement cost, let’s first cover some of the basics and that is what is a timing belt in general terms? Many beginners who are just starting with cars have no clue about this stuff, so if you feel like you have a better grasp of the matter you can move on to the following chapters. If not, keep up with us for a bit while we explain this.

The timing belt in general is a simple belt that connects the crankshaft at the bottom and the camshaft or camshafts at the top of the engine.

These belts are only used in engines that are called overhead camshaft engines or OHC. This is an interference engine design where camshafts are located at the top of the engine. Meaning that they are located above the engine head.

This is why these engines are called interference engines. Meaning that the engine valves and pistons interfere with each other. If there is no proper timing of the engine. They could collide with each other.

And that’s why the timing belt is there for. This belt basically keeps the top of the engine and the bottom with the right timing. When the valves open, the piston is rolled down. And when the valves close, the piston goes up. If the timing is off, these components will collide and there will be damage. So, you can understand how important this belt really is.

Usually, in the shops, these belts are dealt with by the most experienced mechanics. Since the risk of engine damage is too big to leave this job for a beginner. But what does the timing belt replacement cost? More on that in a bit.

Timing Belt Tensioner

Now before we dive deeper into this topic, let’s discuss the timing belt tensioner. This tensioner is a crucial component when it comes to the proper operation of this belt. But what does this component really do?

Well, this tensioner has a simple role and that is to keep the tension on the belt. Meaning that the tensioner needs to keep the belt very tight. But not too tight since you could damage it.

This tensioner basically resembles an idler pulley but with a little twist. Unlike idler pulleys that are fixed, the tensioner is basically an adjuster. Meaning that you are able to adjust the tightness of the belt per your liking.

In order to perform this task, the tensioner has a mechanism that allows it to do this. In fact, there are two basic tensioner designs.

The first type of tensioner is a spring-driven tensioner. Meaning that inside of the tensioner there is a spring that is loaded and this spring basically keeps the tension.

The second design is hydraulic. Meaning that the timing belt tensioner works with the aid of hydraulic fluid. In this tensioner, there is a piston inside and this piston works with the help of hydraulic fluid. Some of these tensioners can leak when they fail.

So, you better be aware of what type of tensioner you have in your car. I’m telling this because not all of them work on any application. Now before we cover the timing belt replacement cost. Let’s learn more about the serpentine belt vs timing belt.

Serpentine Belt VS Timing Belt

Now let’s discuss another topic and that is the serpentine belt vs timing belt. A lot of people confuse these two types of belts and think they are actually the same. Which in reality is not the case. It is quite the opposite, they are really different and they implement different tasks.

The timing belt as we said is basically keeping the engine timing in check. It makes sure that the camshaft and the crankshaft are perfectly timed and no interference is between them.

If they are not timed properly, there will be a lot of damage to the internals of the engine. Meaning that the engine valves will hit the pistons and the valves will get bent. This is something that you don’t really want to happen on your vehicle.

The serpentine belt is also known as a drive belt is a different type of belt. This belt doesn’t have anything with the timing of the engine but has a lot to do with powering up the different accessories that are mounted on the engine.

This belt is basically transferring the energy that is created from the crankshaft with the help of the crankshaft pulley. From there, the belt is routed to different accessories around the engine.

What is also interesting about this one is that it does not have teeth as the timing belt has. This is the case because there is no need for such a design since the serpentine doesn’t have always to follow the same timing.

This makes this belt a lot cheaper to purchase and simple to install since there is nothing that you could really mess up and destroy the engine if you do something wrong. Overall, that’s all when it comes to serpentine belt vs timing belt.

Timing Belt Symptoms

Now as we covered the basics of this belt that serves the purpose of keeping the timing of the engine in check. Let’s now learn more about the timing belt symptoms. What symptoms this does belt develop when it starts to fail?

We will cover all of them in the following chapters and after we will discuss more on the timing belt replacement cost. As well as the process that is involved in replacing this belt. So, if you want to learn more, follow along.

1. Check Engine Light

The first in our list of timing belt symptoms is the check engine light. The check engine light will appear if your belt has skipped timing. If the timing is off by a few degrees, the check engine light will be shown. But why does this happen?

Well, this happens because your engine has a camshaft position sensor and a crankshaft position sensor. These sensors are basically monitoring the positions of these two components and determine if the engine has the proper timing.

Timing Belt

If the timing is off, let’s say because your timing belt is loose or it is missing a few teeth, then the ECM will be alerted by warnings from these two sensors. Resulting in a check engine light.

What is good in this situation is that you have good information. The only thing you will need is to get an OBD2 scanner and scan the car for codes. After learning the codes, you will be able to diagnose the problem with this belt. Now let’s move to the next symptoms.

2. Engine Misfires

The second on our list of bad timing belt symptoms are the symptoms when you experience engine misfires. These misfires as you probably know are the situations when you notice some ticks from the engine.

You will hear this noise coming from the valve cover and these sounds will be all over the cylinders. Meaning that not only one cylinder will be the one that is affected and misfiring. But this problem is going to affect all of them.

Since the timing is off for a few degrees, they will all open and close with the wrong timing. The worse the timing, the worse the performance of the engine will be.

You will also experience some pops from the exhaust. You will notice how the exhaust gases that flow from the exhaust are not ideal and that there are some instances when these gases escape the tailpipe more violently.

All, this relates to engine misfires. The thing you need to do is to see if the timing of the engine is good. If it’s not, then you need to replace the timing belt and adjust the timing. But more on that later after we cover all of the symptoms.

3. Rough Engine Idle

Another in our list of bad timing belt symptoms is the rough engine idle. The engine will be idling quite poorly when the timing is off. This rough idle will be attributed to these annoying misfires that we covered previously.

Meaning that the rough idle is closely related to engine misfires. In addition to this, the engine will be also down on power quite significantly and will not perform as it did before when the component was in good condition. Now let’s move to the next in our list of symptoms.

4. Oil Leaks From The Timing Cover

Another in our list of very common bad timing belt symptoms is the oil leaks on the cover. This situation happens on almost any car out there.

This is the case because there is an oil gasket nearby. And this gasket really tends to leak oil from the engine. And this oil drips on the timing belt.

So, as the belt spins, the oil splashes all over the cover. Happened to my dad once in his car. We had to replace the component as well as these seals that keep the oil in check.

What is the downside of this problem is that the oil will splash on the timing belt and will potentially cause it to jump. Since the oil is a lubricant.

Or will heat up the belt and will deteriorate much quicker than previously anticipated. Either way, a bad situation that you probably want to avoid. Now let’s move to the next symptoms.

5. Visible Cracks And Missing Teeth

Another in our list of bad timing belt symptoms is the situation where you can visually see what is going on with the belt. This will be only possible if you decide to open and remove the timing cover.

Removing the timing cover is a smart thing to do. I’m telling this because if the timing belt is nearing the end of its lifetime it will start to show its downsides. And these downsides include developing cracks as well as some of the teeth will be missing.

If you open the cover and see how some of the teeth are missing on the belt, then this is a clear sign that it needs to be replaced along with all of the different pulleys installed in the timing system.

You should not ignore these visual signs like cracks. The more you ignore them, the bigger the chance for damage to be created. Now let’s move to the last in our list of symptoms.

6. Engine Damage

And the last symptom in our list of timing belt symptoms is the engine damage that will eventually occur if your engine skips a few degrees of timing.

What will happen if the belt jumps is the valves and pistons will collide, in this situation you will get bent valves and also damaged pistons.

If the valves are too protruded, then they could also damage the cylinder walls as well. Meaning that the engine will be totaled in this situation. This is an extreme case of timing belt failure and often happens when the timing belt fails catastrophically.

Referring to the situation when the belt snaps completely and the engine gets totaled. This often costs thousands of dollars to fix. So, you probably don’t want this ever happening to you.

In this case, you need to learn how to diagnose a bad timing belt based on the bad timing belt symptoms that we have covered. And that we are going to discuss next.

How To Diagnose?

Now as we know the bad timing belt symptoms, let’s learn something more about diagnosing this issue. How you can tell if you need to replace a timing belt on your vehicle?

Well, you don’t, timing belts are replaced at specific intervals of about 60,000 miles or so. And this should be done regularly if you don’t want to experience some of the symptoms that we covered above.

The moment you start to experience weird symptoms means that something is going down pretty fast. And by this, we mean the misfires, oil splashes on the timing cover, and poor engine work.

The only way to make sure that the component is bad is to remove the cover. Remove this cover and see the condition of the belt.

See if it’s tightened up to spec and if it’s in good condition. By good condition, we mean that the belt is not missing some teeth and does not have cracks. If it does, then you should look into the timing belt replacement cost.

Timing Belt Replacement

When it comes to timing belt replacement, it is often advised not to do this work by yourself. If you do, you are risking creating engine damage.

And even if you do, you need to have the right repair manual for your vehicle. In this manual, there is everything you need to know when it comes to a timing belt replacement. There are markings on the block and the cams that need to be followed properly if you don’t want to ruin your engine. Now let’s cover the timing belt replacement cost.

Timing Belt Replacement Cost

When it comes to timing belt replacement cost, it is worth noting that it is not as cheap as you probably think it is. It cost more to replace than your regular serpentine belt. This is the case because it requires some skill for this job to be performed in the right manner and not a lot of people know how to do it.

Timing Belt

The minimum cost is about $300 for the labor and parts. Just take a note that this cost can even go higher and reach up to $8,00 or more in some cases. Depending much on the make and model.

Timing Belt: Signs Your Car Needs a Repair – Facts

  1. The timing belt rotates the engine’s cam and crankshaft in sync, ensuring each cylinder fires at the appropriate time.
  2. The timing belt is an internal engine component located under a timing cover near the front of the engine.
  3. The timing belt is likely manufactured from high-quality rubber and will need to be replaced from time to time.
  4. Ticking noise coming from your car’s engine could be an indication of a worn-out timing belt.
  5. A broken or irreplaceable timing belt will cause your car’s engine to not turn over or ignite properly.
  6. An oil leak around your engine could indicate a problem with your timing belt.
  7. Timing belt issues can lead to excess smoke from your car’s exhaust.
  8. A worn-out or broken timing belt can cause strange RPM readings.
  9. Highly-rated auto mechanics recommend replacing your timing belt every 60,000 to 100,000 miles.
  10. You can check your owner’s manual for the manufacturer’s recommendation on when to replace your timing belt.


In this article, we have covered quite a bit when it comes to the timing belt. First, we learned what this belt is and how does it work. Then we discussed the timing belt vs serpentine belt and learned the differences between the two.

Then we covered the symptoms of a bad belt and what you should expect when it comes to a problem like this. After we covered the diagnosing and the timing belt replacement cost

Timing Belt F.A.Q

Now let’s answer some frequently asked questions on this topic.

What Is A Timing Belt

This is a special belt that is there to synchronize the rotation of the camshaft and crankshaft. Meaning that it adjust the timing accordingly so the components inside of the engine like the valves and pistons do not collide with each other. Thus the name timing belt. This is a crucial component and it should always be in proper working order if you want to avoid a possible catastrophic failure of this belt.

How Much Is A Timing Belt

The cost of the kit varies from manufacturer to manufacturer. Some of them are more expensive while some of them are cheaper. But the average cost for a timing kit is between $150 to $350. We are talking only about the parts here and there are other parts included in this kit like the pulleys, water pump, etc.

How Much To Replace Timing Belt

The cheapest to replace it is about $300. But this price can go up depending on the make and model. The cost to replace this belt can climb up to $1,000 in some cases on cars that are too difficult to work on.

When To Replace Timing Belt

The average mileage for replacing this belt is between 60,000 and 100,000 miles or every 5 years. Your best bet would be to replace the belt at the 60,000 miles mark if you want to avoid this belt snapping and creating damage inside of the engine.

How To Check Timing Belt

In order to check the component, you will need to remove the cover and inspect its condition. Make sure that the condition of the belt is good and that there are no teeth missing from it. Also, inspect it for cracks and see if it’s tightened up to spec. If it’s loose, make sure that you tighten the tensioner of the belt.

What Happens When Timing Belt Breaks

When this belt breaks, there will be engine damage if this is an interference engine. Meaning that the pistons and valves will collide with each other. When these components collide, there will be internal damage and the engine will need to be opened and the bent valves replaced. If there is too much damage and the cylinder walls are destroyed, then you will need a completely new engine. This is why the replacement of this component is such important for you as a car owner.

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