We receive a lot of questions about the timing belt. Therefore I decided to write this article to answer all your questions about a timing belt. My name is Magnus and I have been working as a car technician for several years and have seen many timing belts that broke and destroyed the engines.
In this article, I will tell you about my experiences in this field free of charge. I will answer your most frequent questions, what you need to know about timing belts and how you can avoid a very expensive visit to the garage.
Why is it so expensive to replace my timing belt?
Replacing a timing belt is often a very big job. It depends very much on the make of car and engine, but in general, it is very time consuming and many parts have to be replaced. Many people think that you only have to replace the belt itself and not the surrounding parts. I can tell you that in almost all cases of belt failure, it is not the belt that breaks. It is either the water pump or a tensioner that is worn and causes the belt to break.
When changing the belt, always make sure that your mechanic replaces all tensioners and the water pump. Many small workshops will not give you a price for the replacement of all necessary parts because they want to offer you the lowest possible price. As I mentioned before, it is usually not the belt itself that breaks. So what happens if you only replace the belt and the tensioner and the water pump is still not replaced? Yes, that’s right, your timing belt will probably break anyway and you will probably have to replace the whole engine.
So in this case it would be worth paying a little more to replace all the parts necessary for correct timing belt operation.
In many cars, you will also want to replace the generator/AC/fan belts at the same time, because they are often difficult to reach and you have to remove them anyway while changing the timing belt.
Here are some examples of parts that usually should be replaced in a timing belt job:
- Timing belt
- Tension wheel
- Idler pulleys (usually 1-4 pieces)
- Water pump
- Serpentine belt & idler pulleys & tensioners to that.
As you can see, there are many parts that should be replaced, not just the timing belt. Replacing these parts is not free, so your mechanic may give you a price without these parts to make it sound cheaper, and you will probably choose their garage because they have given you the best price. It is very common for customers to come to me and say they got a price from another mechanic who does the same work for half the price. It is impossible that this garage will do it for half the price and replace the same parts.
Cost of parts $300.
Cost of work $100 per 2 hours.
I give the customer a price of $500 for the work. The other one will do the same work for $250. Either he works for free and buys cheaper parts or he just doesn’t replace all the necessary parts. There is no way he can buy the same parts for half the price I pay unless he buys really cheap porcelain parts, which I do not want on my car for these critical parts related to the timing belt. It could be much more expensive if it fails.
I hope you see how impossible this is and why you should always check his offer carefully and really check which parts are really being replaced and what quality you get for the parts. Don’t just check the price of the order, because in the end, it may cost you a lot more.
Here is an example of an Audi where it is very difficult to replace the timing belt.
As you can see, you have to remove the entire front of the car and you don’t want your mechanic to do this work several times. Therefore I recommend replacing all the necessary parts the first time. Normally you don’t have to remove that much, but you have to loosen the front part to get between the front and the engine. As you can see, you have to remove the serpentine belt, which you should, therefore, replace at the same time, because you don’t want to do the same work again if you didn’t replace it the first time. Not all cars are that extreme, but it should give you just a hint as to why I mention this.
When Do I Have To Replace My Timing Belt?
This is a very difficult question to answer. The best answer to this question is to call your authorized car dealer.
I give you this advice because in many cases the original vehicle information is not updated. If the manufacturer of the car engine has many reports of many broken camshaft belts, the car manufacturer will issue new information and reduce the number of kilometres between belt changes. It will take some time for this information to be released to all car service information platforms, and if you are unlucky you will get wrong information and your timing belt may break and your garage visit will be very expensive.
Many garages claim that they can check your timing belt and tell you whether it is time to replace it or not. Sure, you can check if the belt has cracks or not, but I don’t think that will help you much, because I have almost never seen a timing belt crack; it is almost always a water pump or a tensioner that causes the timing belt to fail. You cannot see the condition of the water pump, tensioner, and pulleys by just checking the timing belt – at least, I can’t do that.
Therefore I always recommend changing the belt within the mileage interval.
If you don’t have any documentation about when the timing belt has been changed before, you should consider that it has not been changed at all. Because what happens if you think it has been changed and it has not been changed? Yes, your belt will most likely fail because the belt does not listen to whether you think it has been changed before.
Sure, there could always be falsified documents that it has been replaced. But in this case, you could hire a mechanic to check the belt and probably sue the person who wrote the documentation. This is because in most cases when a good garage has made the replacement, they will have a stamp for their garage in your service documentation.
Do I have to replace the belt within the exact mileage?
You should never drive beyond the mileage specified by the manufacturer. The mileage they specify is often calculated very high to reduce the service costs they spend when selling the car.
I always recommend replacing the timing belt well in advance, usually 10000km (6200 miles) ahead of time. I have seen many cars that have driven many miles over the “recommended distance” indicated, and if you are lucky it might work, but why take the risk? It is much cheaper to change the belt than the whole engine if it fails.
You make your own decision here, is it worth it?
What happens if my timing belt fails?
Your timing belt is driven by the crankshaft; it turns the camshafts at half the crankshaft speed. It makes sure that the camshafts open the valves inside the car at the right time. These words probably don’t make any sense to you at all. But don’t worry, I will answer your question now!
If your timing belt fails, in most cases it will be a very expensive workshop visit. There are some older cars where the valves don’t hit the pistons if the belt breaks, and in this case, you could simply insert a new timing belt into your engine. But in most cars, if the belt tears, your valves will hit the pistons and probably destroy valves, pistons, crankshaft, etc., depending on the RPM at which it happened.
In most cases, if your belt has failed at a high RPM, it is easiest and cheapest to replace the entire engine.
If you are more interested in how the belt or motor works and what happens in detail when your belt breaks, I recommend this detailed video:
Can I replace the timing belt myself at home?
You can change the timing belt yourself at home if you feel that you have good knowledge and take the risk if something goes wrong. It is not an easy job: I know many car mechanics who do not want to change the timing belt because they do not feel comfortable taking the risk if something goes wrong.
If you want to replace the timing belt yourself, you should find a good repair manual to do the job correctly. To find a repair manual for your engine, you must know your engine code. If you know your engine code, you can either search for a repair manual on the Internet or you can buy an e-book. Just use the search function, there is a lot of good information available if you just know how to find it.
As you can see in this picture, replacing a timing belt is not always that easy, because there is often not enough space to reach the screws easily.
If you have decided that you want to try to change the belt yourself, I can recommend this video. It is a general video, and it does not give you exact instructions on how to do it in your car. But it might give you a good idea of how to do it.
My tip: If you want to replace it yourself, always mark all gears before removing the belt. After you have replaced the belt, turn the crankshaft 2 full revolutions. The marks you made should be in exactly the same places as before.
NOTE: On some cars, you can loosen the large screw on the crankshaft belt pulley. The crankshaft sprocket is a “floating” sprocket; if you mark the sprocket and mount the belts according to these marks, you will probably destroy your engine.
In this case, you will have to use a special tool to lock the crankshaft.
Therefore I always recommend reading a repair service manual on how to do this carefully at every step.
NOTE 2: Some engines also have the high-pressure fuel pump gear on the timing belt. In this case, you must install it in the same way even after replacement. If not, the car will probably not start or it will run roughly. The new belts are often shorter than the old ones, and your pump mark will not be in the same place as before, so your engine will probably not run well. In this case, you will need to find a repair manual that describes how to adjust the timing of the fuel pump.
You may also see that your engine has a differential gear; you must make sure that you also align this gear, otherwise, your engine may vibrate.
After you have removed the timing belt, never turn any gears. You could damage your engine.
How do I know if I have a belt or chain?
You could find your engine code on the Engine Code Finder website then search the Internet to see if you can find information about it. But the best and most reliable thing you can do to be really sure is to call your authorized car dealer. You can give him your license plate number and he will see in his database whether you have a chain or a belt.
Another thing you can do is open your hood and check the front of your engine. If there is a plastic cover, there is a good chance that you have a timing belt. If there is no plastic cover, you probably have a timing chain. But do not trust this method, I recommend you always call your car dealer to be 100% sure.
What is the best, timing belt or chain?
This is a question that is difficult to answer. I like to have a timing belt because you can change the belt and then know that the engine will run to the next scheduled timing belt change.
Timing chains also fail and are a very common problem with many newer engines. With timing chains, there is no recommended change interval in most cases and you never know how long it will take. Replacing a timing chain is often much more difficult than replacing a timing belt.
So ask yourself if you want to drive around without replacing the chain in the knowledge that the parts are old and can fail at any time?
If you change your timing belt in time within the recommended time, it will probably not fail, and knowing that could be reassuring.
I always choose a timing belt when I buy a car.
- Always replace your timing belt within the recommended time period.
- Make sure your mechanic changes all the necessary parts.
- If your timing belt fails, you probably have to replace the whole engine.
- The replacement of a timing belt is often a very large job.
- If you are going to do it yourself at home, get the right documentation and repair service manuals for the job.
I hope you like this guide and that you now have a little more knowledge. If you want us to add or change anything in this article, you can contact us or make a comment below. If you have a question that is not answered in this article, you are welcome to contact us on our homepage.
See you at the next guide!