squealing serpentine belt can be very irritating when you are driving down the road. This squealing belt noise may cause you to stop your progress, but it does not have to ruin your traveling.
Knowing how to deal with serpentine belt squealing noise allows you to jump in your automobile once again and to quickly get back on the road as you should!
This article covers all of the possible causes of serpentine belt noise while giving you the ability to diagnose the issue at hand. You will also receive ideas on how to fix the problem and cost implications to consider.
Finally, at the end of the guide, we will provide answers to your most frequently asked serpentine belt noise questions.
Causes of squealing serpentine belt
A bad serpentine belt, bad tensioner, or stuck or bad idler pulley can create squealing serpentine belt noise. There may also be a non-mechanical problem that can cause squealing serpentine belt noise, such as coolant exposure or cold weather.
#1. Worn Out Belt.
Serpentine belts do not last forever due to the synthetic rubber construction; you can expect it to last between 50,000 and 100,000 miles in most vehicles. As the belt wears out, the ribs, and fibers cause it to move more roughly on the pulleys.
As the belt drags a variety of noises begin to occur including squealing. The squealing may worsen as the belt continues to wear until it finally breaks.
#2. Bad Tensioner.
The serpentine belt has to be regulated by the drive belt tensioner, which is its own pulley attached with an adjustable pivoting function to guide the belt.
When the tensioner wears out, it is unable to hold the drive belt tight. With the belt becoming loose, strange noise is sure to follow as you accelerate the vehicle. If the belt becomes very loose, it is likely to come off creating damage.
#3. Faulty or Stuck Pulley.
Throughout the belt system are various pulleys that help to spin the accessories such as power steering, alternator, and AC compressor. These pulleys contain spinning grooves to keep the belt spinning smoothly.
When one of the pulleys wears or the accessories become stuck and turns with a lot of resistance, the belt will begin to slip on the pulley causing a squeaking or chirping noise. This can lead to more damage to the serpentine belt including slipping; therefore, do not wait to fix it.
#4. Misaligned Idler Pulley.
In the system, along with the other pulleys, there is an idler pulley as well as a tollkeeper for the belt to keep it on course.
If it is damaged or misaligned, the belt will not move properly. It will likely begin slipping and cause increased wear, along with additional squealing sounds.
#5. Coolant Exposure.
Mechanical failure is not the only source of problem. If you get coolant or antifreeze on the belt, you likely will also notice some squealing sounds. Even a small amount can create a maze of problems, which is the goal for mostly be cautious of during maintenance processes.
Additionally, antifreeze could drip onto the belt if there is a leak in any of the hoses. Either way, the coolant is going to make the belt slip and squeal. You could very well have to replace the belt.
#6. Cold Weather.
When the temperature drops, there are many aspects of the car that are affected, including the serpentine belt. If you are only hearing the squealing when the temperature is cold, you may not need to do anything quite yet. By the time you get the engine warm, the belt should stop making noise.
Whether or not you need to do anything, it is still a good idea to bring it to attention. In fact, cold weather can actually increase damage faster as the material becomes more brittle.
How to Diagnose Serpentine Belt Noise
#1. Listen/Pay Attention.
To begin, take note of the sound. If the squeal happens only when the car is cold and stops as soon as you get going, you may not have anything too serious.
That’s why it is good to note when the sound happens at this point. You also want to listen for which side the sound is originating from.
#2. Examine Belt.
When you are ready to diagnose the problem, the first place to start is with the belt itself. Most of the time the belt is simply old and brittle and needs to be changed. After all, this belt gets a lot of friction and constant movement.
If you see any cracks on the belt, then it is close to snapping and you can properly determine that you need to take action. Even if there is only a minimal amount of wear, it is far better to replace it soon than late before distractions or serious problems crop up.
#3. Look for coolant.
If you just recently added coolant to your system and may have gotten some on the surface of the belt or even if there are any leaks in the system, then it may also be the source of your problem.
Unfortunately, once coolant has been applied to the surface of the belt, there is no way to easily clean it off. More than likely the belt has soaked in the coolant leading to permanent damage to the belt. In order to eliminate the squealing from the belt, you must install a new belt.
#4. Tighten the Pulleys.
If the belt is loose, it will squeal. After your inspection, if you don’t find anything physically wrong with the belt, check the pulleys next.
While the belt is turning, there should be non-slack. If you find some, you will need to pull in the pulleys. This should not generally be a difficult job and does not usually require you to take off the belt to do. However, if you find, the pulley needs to be replaced, you will need to pull the belt off.
Most modern pulleys are automatic and if the tension is bad, you may have to replace the pulley tensioner.
#5. Go to the Mechanic.
If the above two steps did not uncover the problem, you are going to need some more help. You may not want to call a mechanic, but it is necessary if there is no answer to your problem.
Do some research on local auto repair shops to see who gets good reviews in your area. You should only expect to pay, maybe, an hour of labor to figure out what is wrong with your vehicle.
How to Fix Serpentine Belt Noise
#1. Diagram of serpentine belt.
All serpentine belts tend to snake around multiple accessories and pulleys in a funny form – is there any reason why these serpentine belts are called serpentine belts? The unique design of how the belt snakes around is unique to your vehicle. Before you remove the belt, you should think about what the belt’s path is.
You could take a picture of how the belt was installed. There should also be a diagram under the hood of the car. If it is not under the hood, you want to get a copy of your service manual. If you incorrectly place the belt, you could be in trouble!
#2. Release tensioner.
Before you take the belt off, you need to release the tensioner. The tensioner is going to keep the belt snug and tight, so you do not want to take it off until it has been released properly. Most designs have one of two different ways to release them.
It may have a ½- square cast to the tensioner arm and you will need a belt tensioner tool or breaker bar. Other designs may have a socket to release tension using the pulley, so be aware of the design to release the tension properly and use caution when removing the belt.
#3. Remove belt.
After you have released the tension, you are now ready to take the belt off. Use caution with this step because you do not want to damage any of the pulleys or any additional equipment related to the belt’s route.
When removing the belt you will be able to further inspect it. If the belt was wearing due to alignment, you will want to fix this issue now before you put the belt back on as a new belt will not fix it.
#4. Inspect/Fix Pulleys.
You can align the pulleys with a straightedge. You also want to clean off the pulleys so there is no grime on them.
Take the time to spin all of the pulleys, even the idler pulley and tensioner pulleys. They should spin freely, without any noise.
You should also turn the pulleys for the power steering, alternator, and AC compressor, to ensure they spin freely and do not have any side-to-side play. If you have issues, replace the pulleys since the belt is already off.
#5. Install New Belt.
With your new serpentine belt, you can put it back into position. Snake it through the same routing you set aside earlier. Once in position, release the tensioner to tighten the belt.
Recheck that the belt is centered on the pulleys, and not slipping off anywhere. Once you are satisfied, you can start the car.
#6. Test Drive.
Start the car engine, and let it idle for a minute. You can observe the serpentine belt to ensure it is turning in the proper direction, but do not put your hand in its way while moving.
Once you think everything is okay, take the car for a drive. Listen to ensure that all of the squealing noise has gone away.
Cost to Replace Serpentine Belt
Expect to pay close to $50 for a new serpentine belt as an average price. If you’re able to do the belt installation yourself, labor costs would be zero. Hiring a mechanic will cost you an additional $50 to $150 for labor.
The labor cost is determined by the make and model of the vehicle. Some vehicles are more difficult to install a serpentine belt than others.
What does a failing serpentine belt sound like?
The belt will make a squealing noise, but it can also make a clunking, chirping and squeaking noise. The noise will often replicate what you expect in a bad accessory bearing, which is where the confusion comes with diagnosis.
Can I drive with a squealing serpentine belt?
No. It is recommended to put a new serpentine belt on a vehicle at the first indication of failing. The serpentine belt drives many systems in the vehicle, including all powered steering, air conditioning and alternator if your vehicle has one.
It could lead to serious damage and in a lot of cases, these systems will simply stop working.
How expensive are serpentine belt repairs?
With almost all vehicles, serpentine belt repairs are inexpensive. The cost of a serpentine belt can be around $50 in parts, and the cost for labor would be an additional $50 to $150 or so.
In problematic cases, some vehicles are harder to install a serpentine belt and you will pay more in labor cost.
What Happens if the Serpentine Belt Breaks While Driving?
The serpentine belt runs many important accessories. If your serpentine belt gets damaged or breaks, you could lose steering wheel assist, lose air conditioning or the alternator could stop working.
The worst case scenario is that if the serpentine belt also runs your water pump, the belt could cause the water pump to stop circulating coolant, and cause your engine to overheat.
How long does a squeaky serpentine belt last?
Generally, you could expect a serpentine belt that is in good condition to last up to 50,000 to 100,000 miles (the finish of the serpentine belt is largely dependent on the compound of the rubber material the belt is made from), however, if it is squealing, that greatly reduces the expectancy and longevity of the belt.
Friction and heat reduce the life expectancy of the belt as it will wear away due to the added stress of friction and heat. The best course of action, if you hear any squealing from under your hood, is to investigate it right away.
There are a number of different causes of the serpentine belt squealing and they should all be addressed sooner rather than later. Make sure to not ignore and just put off fixing the squealing, it will only end up getting worse and worse, possibly resulting in an even more expensive repair.
Simply follow along with our guide so that you can address your issue and ensure your car works as intended, and most importantly get rid of unwelcomed noise. If you’re not sure how to investigate and fix the issue, you can always take it to a mechanic and they will be able to diagnose and problem solve your issue without much trouble.