Aside from the pulley for the drive belt tensioner, the idler pulley can also be a catalyst to the serpentine belt noises due to the misalignment. ... This problem is usually discovered after a new belt still squeals, wears down fast, or makes loud serpentine belt noise.

Why is my brand new belt squealing?

A new belt is recommended once the accessory drive has been realigned. “Squeal” is a high pitched noise, typically lasting several seconds in duration. This type of noise will typically increase in volume as the engine speed increases, and is caused by relative slip between the belt and pulleys.

Is it normal for a new serpentine belt to squeal when cold?

The noise you are hearing is that new serpentine belt sliding and skipping on the pulleys they are driving. This is typically caused by the belt being loose, or a pulley refusing to turn freely. Your vehicle is equipped with one pulley who's only job is to keep the belt tight.

Why won't my serpentine belt stop squeaking?

In most cases, removing the moisture will stop the squeal. Allow the engine to run for a few minutes, then spray rubber dressing, also known as belt dressing, onto the belt in the same manner employed above. This will treat the belt and remove any further contaminants from the ribbed surface.

Why is my car making a high-pitched squealing noise?

1. A high-pitched squeal when accelerating. If you notice a loud squeal when accelerating, especially if your car is just warming up, it could be that you have a loose or worn fan belt. Usually if your fan belts are worn, it could mean your timing belt needs to be replaced as well.

How to Fix a Squeaky Belt (figure out where the squeak is coming from)

15 related questions found

What is the squealing noise from car when starting?

What Makes Your Vehicle Squeal when Starting. Most of the time, the squealing is do to something called a serpentine belt. When you open your hood, it's the incredibly long belt that winds around multiple pulleys. It connects the crankshaft to other systems like the alternator, power steering, AC, and water pump.

What does it mean when your belt squeals?

Your engine belts make a screech or squeal noise usually because the rubber belt is slipping on the metal pulley and just like your tires spinning on the road, this causes noise. The belt may be slipping due to improper tension or because it simply has gotten old and the surface has become glazed, cracked or brittle.

Why do belts squeal accelerating?

A squealing noise, often heard at engine startup, sudden acceleration, air conditioning turn-on, or during a U-turn is typically caused by belt slippage due to improper tension and/or a badly glazed belt. Serpentine belt systems typically employ a spring loaded belt tensioning pulley and sometimes these can go soft.

What belt squeals when I accelerate?

If you hear a chirping or squealing noise when you accelerate, it usually means a belt is loose and slipping or the drive pulley for an accessory has become misaligned.

Can a belt tensioner making noise?

When the tensioner or tensioner pulley fails, the loss of tension can cause the belt and pulleys to make high-pitched rattling or chirping noises. If the pulley bearing completely fails, it can also cause a squealing or even a grinding noise.

Will belt dressing stop squeal?

Belt dressing, or belt conditioner, is a spray for the rubber belts that are used in cars, trucks, lawn mowers, and tractors. Spraying belt dressing on a belt softens the rubber and keeps it from drying out and slipping. ... It can also prevent and stop squeaks caused by a slipping belt.

Why does my serpentine belt squeal when it rains?

The rain can cause the belts to slip (similar to tires slipping on a wet road) and make a high-pitched noise for a few moments. In most cases after the engine runs and warms up, the squealing will dissipate. If the belt isn't properly tensioned, it may be cracked and in need of replacement.

What causes squealing noise while driving?

The most common reason your vehicle may make a squeaking noise when driving is due to worn brake pads. ... As your pads clamp down on the rotors, the bits of dust caught between them can cause the brakes to produce a high-pitched hum. Washing your car and spraying the wheel wells should silence them.

Can a bad alternator cause belt squeal?

A squealing alternator pulley is not only annoying, it indicates a problem with the car's belts or alternator. Left unattended, the problem that causes a pulley squeal will likely become worse and lead to expensive alternator or engine repairs.

How tight should a serpentine belt be?

In many applications, the serpentine belt needs only to be reasonably tight. ... The belt should have about a half an inch of play when at the appropriate tightness. If there is less than a half an inch, the belt will need to be loosened, if there is more, it will need to be tightened.

Will soap stop a squeaky belt?

Sometimes a belt will squeal upon starting a vehicle and will disappear shortly thereafter. ... That's right, ordinary bar soap can usually stop the squealing when rubbed on a fan belt. Just a few rubs on the belt with bar soap can solve the bar squealing problem for quite some time and save money in the process.

What does a loose serpentine belt sound like?

The symptoms of a loose belt include serpentine belt noise when the engine is started or when you turn the steering wheel all the way to the left or the right. ... Your serpentine belt could come loose and cause serpentine belt noises, resulting in the louder sounds when you accelerate.

What causes the tensioner pulley to squeak?

If the tension is too low, the belt will wobble and won't have enough friction to drive the pulleys it's running on. If this is the case, the engine belt will slip on the pulley causing the annoying squealing noise you hate. ... The auto belt tensioner is a spring loaded arm with a pulley on the end.

What sound does a bad tensioner pulley make?

When the tensioner or tensioner pulley fails, the loss of tension can cause the belt and pulleys to make high-pitched rattling or chirping noises. If the pulley bearing completely fails, it can also cause a squealing or even a grinding noise.

What are the signs of a bad belt tensioner?

• Rust bleed and cracks. Appearance: Rust is bleeding between arm and base or dripping from the tensioner. ...
• Pulley bearing wear. ...
• Pulley wear. ...
• Tensioner assembly misalignment. ...
• Tensioner noise. ...
• Tensioner arm misalignment. ...
• Excessive tensioner arm oscillation. ...
• Binding or grinding tensioner arm movement.

Can a bad serpentine belt cause rough idle?

Poor Driving Experience

Vehicle performance issues can also indicate a problem with your vehicle's serpentine belt because bad serpentine belt causes loss of power. ... So if you have searched for answers to the question, can a bad serpentine belt cause rough idle? The answer is yes.