Symptoms of Bad or Failing Timing Belt: How to Check and Changes?

A timing belt is an essential internal engine component that links the crankshaft and the camshaft to ensure adequate sync rotation and enable the cylinders to fire appropriately. Timing belts are made of strong rubber nylon-reinforced cords that can stand the taste of time. Despite the material utilized in manufacturing the timing belt, it is subject to wear out or break due to the incredible force that it links together and will eventually need to be replaced. Your engine will not run properly without a fully functioning timing belt. Hence, you should know the symptoms of the bad timing belt.

Not all cars utilize a timing belt. The timing belts are commonly seen on most small cars and trucks that have a small engine compartment. Timing belts have predetermined dates to replace them, but there are signs you need a new timing belt.

Common Symptoms of a Bad Timing Belt

A few timing belt warning signs indicate you have a worn-out or broken timing belt, which will require you to replace or contact a professional mechanic to replace it and diagnose other internal components.

loose timing belt symptoms

Engine Misfires: A worn-out timing belt can affect your engine firing order. As the timing belt drives the cam and the crankshaft in sync rotation, a worn-out tooth can cause the timing belt to jump a tooth on the cam or crankshaft sprocket and cause the cylinders to open randomly. If this happens, you can lead to engine blow-by if not replaced on time.

Ticking sound from the engine: As indicated above, the timing belt is attached to sprockets that drive the cam and crankshaft in an engine. When the timing belt worn-out or is aging, it’s honestly going to malfunction. You might hear a ticking sound from the engine. Now, be aware that if your car has a low engine oil, you’re going to hear a ticking sound as well, because you’re going to hear those lifters lifting.

So, it’s not like you’re going to take a new timing belt and put it once you hear a ticking sound, no. It means that you should look into it a little bit further. Be aware of your timing belt while inspecting it, and you don’t want to get too close to it if it’s moving. The timing belt is a moving component of your car, so keep a distance while looking into it when you hear ticking from the engine.

Engine won’t start: Another bad timing belt symptom is that your engine won’t start. A timing belt plays a significant role in your engine starting. If your timing belt is wholly gone, missed some teeth due to slippage, or has broken, your engine won’t start. You might hear the starter kicking. You might hear the starter trying to start the engine, but the engine won’t start.

However, there are so many things that could cause your engine not to start. So, if your engine doesn’t start, you might need a new battery, a new alternator, a new fuel pump, or a new starter. There are so many other things that could cause your engine not to start.

The actual timing belt looks worn out: you could look at the timing belt. There are good visual indicators in most engines. Just look through the indicators when the engine is off. You will get a visual indication of whether the timing belt is worn out or not.

Timing belts are made of strong rubber materials, but they are made to wear out and get replaced. If it looks worn out, chances are the belt is long gone. You have to replace it because you don’t want to be stranded on the side of the road.

You have exceeded the recommended mileage: Last but not least, the fifth symptom or sign is that you have exceeded the recommended mileage to replace your timing belt. Check your owner’s booklet,

and see the recommended date to change your timing belt. If you have exceeded the recommended date, just get the cash and replace it. Depending on your car’s make and model, you can replace the timing belt yourself or contact a professional mechanic to replace it.

How to Check Timing Belt

The timing belt is the most crucial replacement component in your car. As we all know, timing is everything! Let’s see how to know when to replace the timing belt. A good rule of a term is to check it every 10,000 miles and replace it strictly as the manufacturers recommend in your service booklet, usually somewhere between 60,000 to 90,000 miles.  There are two ways to check the timing belt. They are as follows:

how to know when to replace timing belt

Visual inspection: In some vehicles that utilize timing belts, there are built-in inspection ports. It means there is usually a small cover on the timing cover that you can easily remove without removing the entire timing cover when carrying out a visual inspection. These covers are typically tightened with two 100mm bolts.

To inspect your timing belt, lose the two bolts and take off the cover. Take a close look at the timing belt, check for any crack, and check for any missing tooth. A single missing tooth can cause catastrophic engine damage, and that could cost you up to 750 dollars of repair. So, it’s a good idea to check your timing belt every 10,000 miles. You will also rotate the timing belt a little bit and see if it is too loose. Because if it is loose, it will cause a bad timing belt noise.

Using a Timing Gun/light: It will be a total waste of time if you take off your engine to check your timing belt and find out that it is still good. So, the best way to avoid this is by checking your timing belt with a timing gun. You can also use the gun to check your timing chain as well.

To inspect your timing belt with a timing gun, you will have to connect your timing gun terminals to your battery terminals. You want to connect it positive to positive and negative to negative. Then, take the inductor sensor, put it on the number one plug wire, and start your car.

Now, as a mechanic or a DIY, take white paint and paint the timing mark on the pulley so it could be easy to read when you flash the light on it. Flash the light on the pulley while the engine is running and rev the engine. If the mark stays in one place, it means your timing belt or timing chain is still okay. But if it’s jumping as you’re flashing the light, it indicates the timing belt is bad. For a visual clarification on how to use the timing gun, watch this video.

How to Change the Timing Belt

Suppose you noticed any of the outlined symptoms above and found out that the timing belt needs replacement after an inspection or exceeded the manufacturer’s replacement date. In that case, you have to follow the steps below and replace the belt. You will need proper mechanical tools to carry out this maintenance.

Tools and Other things needed:

  • Underwood work light
  • Ratchet and standard sockets
  • Torque wrench
  • A timing belt (you can get this complete timing kit if you’re doing a complete job)

Step 1. Park your car: park your car on the firm and level ground. Engage your hand brake.

Step 2. Remove the battery terminals: Remove the battery terminals to avoid any spark during this maintenance.

Step 3. Remove the drive belt: you have to remove the drive belt out of the way.

Step 4. Remove engine accessories: The alternator, the power steering pump, AC compressor may be blocking the timing cover.

Step 5. Remove any engine mount that may be blocking your way: you have to uninstall any engine mount on the way, you will have to support your car with a jack stands.

Step 6. Remove the crankshaft pulley:  This is very important you unbolt the crankshaft pulley bolt and get it out of the way. If you’re working on a manual transmission car, you have to break-free the crankshaft pulley bolt before removing the drive belt. The pulley might prove stubborn to pull off. You can get a pulley removal tool for few bucks and get the job done without much stress.

Step 7. Unbolt the timing cover bolts: Grab your wrench and the right socket size and break-free the bolts. Unscrew them with your hand.

Step 8. Mark the timing marks: you want to mark the cam and valve cover, the crank, and the oil pan, so you don’t forget the timing. But if you have to turn the engine after removing the timing belt, you have to turn your engine to TDC, learn and mark the timing marks.

Step 9. Release the timing belt tensioner: Release the timing belt tensioner so you can easily take off the timing belt.

Step 10. Remove the old timing belt: Get the old timing belt out of the way.

Step 11. Install the new timing belt: Install the new timing belt and ensure that it is well-aligned with the pulleys. You can a complete timing kit so you can replace any other components that need replacement.

Step 12. Reinstall the timing cover: Fix the timing cover in place and torque down the bolts.

Step 13. Reinstall the crankshaft pulley: Reinstall the crankshaft pulley and torque it according to the manufacturer’s spec. Then, reinstall any other accessories that you removed earlier.

Step 14. Reinstall the Drive belt: Reinstall the drive belt the same way you removed it. Ensure the belt is well-aligned on the appropriate pulleys.

Step 15. Start your engine and confirm your work: well-done if you get this right. You can start your engine and allow it to idle before hitting the road.

For a visual clarification on how to replace your timing belt, watch this YouTube video.

Frequently Asked Questions (FAQs)

What does a bad timing belt sound like?

A failing bad timing belt sounds like a ticking noise in front of your car when it starts wearing out. If the belt eventually breaks, it will give a whining noise when trying to start the engine. A whining noise sounds like no compression in the engine.

How do I know when my timing needs replacement?

A few signs or symptoms will indicate when you have to replace your timing belt. So, when you notice these signs, you should inspect and change your timing belt.

  • Engine misfires. Note that a lot of things will cause your engine to misfire.
  • Ticking sound in front of your car. When your timing belt starts going bad, you may hear ticking sounds.
  • The engine won’t start. If your timing belt break, your engine will not start. Note that several things can cause your engine not to start.
  • The actual timing belt is worn out. When you notice that your timing belt is worn out, it is the right time to replace it.
  • You have exceeded the recommended replacement date. If you have reached the manufacturer’s recommended date for replacement, you have to replace the belt.

Can I replace the timing belt myself?

Timing belt replacement needs a professional mechanic to handle. But if you’re a good DIY, you can replace the timing belt yourself by following the step by step guides above.

How long timing belt can last?

Well, this solely depends on the timing belt you used the last time you replaced your timing belt. However, on average, all timing belts should be replaced between 60,000 to 90,000 miles or 7 to 10 years, whether it covers the mileage or not. All the same, I recommend you check your service booklet to know when to replace your timing belt.

Final words

At this point, you must have known jumped timing belt symptoms, symptoms of bad timing bad, and how to replace it.

However, you should note that replacing a timing belt can be a professional service and can cause catastrophic engine damages if not carried out correctly. You should carefully follow this guide to replace your timing belt. But if you’re not coming with this guide, you can contact a professional mechanic to replace your timing belt.

Osuagwu Solomon

Osuagwu Solomon is a seasoned automotive technician for the past 9 years, and a technical writer. He loves writing about auto professional repair guides, DIY repair guides, and buyer’s guide. After spending six years in the automotive workshop, he decided to impact his knowledge to people aside his domain, and he has achieved this by centering his Automotive writing skills on REPAIRS.

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