What causes a serpentine belt to come off?

Belt coming off: Pulley misalignment, belt misalignment on pulley, defective tensioner, or bearing wear in tensioner, idler or driven accessories Belt noise can be hard to isolate, as the sound may seem to be coming from an accessory drive, such as the alternator or air conditioning compressor.

When is it time to replace your serpentine drive belt?

Check for cracks, chunks missing, abrasions, rib separation, uneven rib wear, and damaged ribs. If you notice any of these, it is time to replace your serpentine/drive belt. As soon as you notice a squealing noise, loss of power steering, the engine overheating, or the belt looks bad,…

What causes glazing at the edges of a serpentine belt?

Glazing at the edges of a serpentine belt, or on its ridges or in the grooves, results from the belt slipping. It indicates that friction between the belt and the accessory drive pulley (s) created by slipping has overheated the belt. Fraying at the edge of a belt indicates pulley misalignment.

Why does the belt not come off right away?

The belt does not come off right away either, because I have my friend turn off the truck while im watching the belt, and it turns off fine, and the tensioner does its job. The belt is tight and everything, then I come back 2 hours later and its off. This doesnt make sense.

Why does the serpentine belt keep coming off?

Serpentine Belt Keeps Coming Off. The most common reason is that the serpentine belt is just worn out and needs to be replaced. Another common cause is that the belt tensioner is froze / stuck and not functioning. The tensioner does exactly what it’s name says- keeps tension on the belt. Without tension the belt will come right off.

How do you replace a serpentine belt pulley?

Using the breaker bar or serpentine belt tool, move the tensioner arm against the spring as far as it will move, to its stop. The tensioner arm should move smoothly throughout its range of travel, with firm spring pressure and without binding. Most tensioner pulleys can be replaced independently of the tensioner itself.

When to call a mechanic for a bad serpentine drive belt?

As soon as you notice a squealing noise, loss of power steering, the engine overheating, or the belt looks bad, call a mechanic immediately to diagnose the problem further. YourMechanic makes getting repairs to your serpentine/drive belt easy by coming to your location to diagnose or fix issues.

Is the AC compressor capable of breaking the serpentine belt?

Thank David. Hi there, yes, the air conditioning compressor is capable of breaking the serpentine belt a couple of ways. If the AC compressors seizes while operating, the shock load can snap the serpentine belt. If the AC clutch bearing seizes while the AC compressor is not operating, the belt can snap then as well.

Is the water pump driven by the serpentine belt?

Another important device driven by the serpentine belt is the water pump. This is not always the case as on a lot of cars the water pump is driven by the timing belt. You should have this in mind so you don’t falsely “accuse” the serpentine belt for overheating.

Can a broken AC compressor cause the serpentine belt to snap?

If the AC clutch bearing seizes while the AC compressor is not operating, the belt can snap then as well. Replacing the serpentine belt tensioner and idler pulley at the same time as the belt is always a good idea. They wear out too!

Why is my AC belt no longer working?

In some cases, this may be attributed to a loose belt, or perhaps water or oil contamination. However, in other cases this may be attributed to a severely worn belt that can no longer properly grip the pulleys.

Can a car run without a serpentine belt?

However, these devices cannot function properly without the help of a serpentine belt. This one long continuous belt is the force that drives many of the engine’s peripheral devices. There is usually a belt tensioner or idler pulley to guide the belt as it moves. What is a Serpentine Belt? What is a Serpentine Belt?

When to test a worn serpentine belt tensioner?

A worn automatic serpentine belt tensioner can cause belt squeal, misalignment and belt chirp, and alterantor bearing damage. Automatic tensioners tend to wear out at around 100K miles. If you have a belt noise or vibration and you’ve changed the belt, it’s time to test your belt tensioner.

What happens when a belt is worn out on a car?

What happens is that the bearing for any of these pulleys the belt rides on is worn out, so the pulley either wobbles or does not sit flat and gives the belt a chance to “walk” off the pulley. A worn out pulley will usually be accompanied by a growl or whining noise when the engine is running.

Why is my power steering belt not working?

This is the part that you must adjust or release the tension to install the belt. Another possible cause is that one of the components with a pulley that the belt rides on is worn out and not sitting perfectly straight. This could be the water pump, power steering pump, A/C compressor or what is called the idler pulley.

What causes a belt to come off without tension?

Another common cause is that the belt tensioner is froze / stuck and not functioning. The tensioner does exactly what it’s name says- keeps tension on the belt. Without tension the belt will come right off. This is the part that you must adjust or release the tension to install the belt.

Why is my belt tensioner not working properly?

Another common cause is that the belt tensioner is froze / stuck and not functioning. The tensioner does exactly what it’s name says- keeps tension on the belt.

What causes a belt to fail on a pulley?

A malfunctioning belt tensioner is likely, as well as other component along the belt drive system, to cause failure with the belt. Have a technician remove the belt and make sure all of the other components spin freely at the pulley. The technician will be able to determine if the belt is shredding due to misalignment.

When does the serpentine belt come off on a 2006 Ford Fusion?

Today is the4th time that the serpentine belt has come off on my 2006 Ford Fusion with a 4Cyl engine. Have had the valve cover gasket replaced due to excess oil on belt and the cover was leaking. Have had all the pulleys cleaned and the belt replaced twice since then. any ideas?

Why does my car make a slipping belt noise?

Belt noise can be hard to isolate, as the sound may seem to be coming from an accessory drive, such as the alternator or air conditioning compressor. A noise that occurs only when the vehicle accelerates is likely to be a slipping belt, as is a noise that occurs only when the car is started cold.

How is the tension set on a serpentine belt?

Depending on the application, your serpentine belt will either have tension placed on it using a movable bracket or an auto tensioner pulley. This pulley uses an internal spring to apply consistent pressure to the belt at all times. If your vehicle does not have a tensioner pulley, the alternator bracket is likely how tension is set on the belt.

Why does my serpentine belt make a squeaking noise when I start the car?

A squeaky belt can indicate several different issues. If the noise only occurs when turning, starting the engine, or accelerating, it probably is a worn or loose belt. A constant squeal may mean the tensioner system or a pulley is damaged. Diagnosing the sound is the first step in how to make a serpentine belt stop squealing.

Do you need to spay the serpentine belt?

While keeping the engine in running state, spay the belt dressing onto serpentine belt and back of the fan belt. You don’t need to move the spray around the belt; the running engine will spin it, and allow to spread the belt dressing to the entire belt.

What are the symptoms of a bad serpentine belt?

Symptoms of a Bad or Failing Serpentine/ Drive Belt . Common signs include a squealing noise from the front of the vehicle, power steering and AC not working, engine overheating, and cracks on the belt.

What is the average life span of a serpentine belt?

The lifespan of the serpentine belt will depend mostly on the type of material it’s made of. Older style belts generally last about 50,000 miles, while those made from EPDM can last up to 100,000 miles.

What causes a serpentine belt to crack?

Excessive cracking is usually caused by old age. Serpentine belts stretch with age and use; as time goes on, the rubber becomes dryer and less pliable making cracking more prevalent. However, cracking can also be caused by a defective tensioner. The tensioner is spring-loaded to keep the belt tight on the pulleys.

How can I test my idler pulley for wobble?

There should be no wobble and no lateral play. Idler pulleys are checked the same way. Next, test the tensioner spring and arm operation. Using the breaker bar or serpentine belt tool, move the tensioner arm against the spring as far as it will move, to its stop.

Do you need serpentine belts or drive belts?

It depends. Most modern cars just have one, a serpentine belt. This belt winds around multiple pulleys throughout the engine compartment so that you only need one. Older vehicles have multiple V belts, to turn each of the pulleys on the various components.

How often should you replace your drive belt?

While a drive belt can last between 50,000 and 100,000 miles, the only true way to know when one needs replacement is by visual inspection. They are made from durable rubber compounds, but all rubber warps over time. Signs of wear like abrasions, cracks, and damaged ribs are sure indicators that your belt is on its way out.

What are the signs of worn out belts?

Signs of wear like abrasions, cracks, and damaged ribs are sure indicators that your belt is on its way out. When driving, this kind of damage can cause squealing noise from the front of the vehicle or engine overheating.

What causes a serpentine belt to come off?