A high-pitched squealing noise coming from under the hood of your car is one of the most common and annoying sounds a car owner can experience. More than likely, it only happens when you start your car or idle the engine.
Then, mysteriously, the squealing disappears the moment you start to accelerate. While a squealing belt is quite an annoying sound, this noise is usually a sign that problems can exist elsewhere, and ignoring its presence can lead to more expensive and intrusive repairs.
Let’s find out the mystery out of this sound. This article will discuss what causes a belt squeal goes away when accelerating.
Topic Summary
What Causes Belt Squeal?
A high-pitched squeak from the engine compartment of your car is typically caused by a rubber belt slipping on the pulley as it accelerates. Like your tires squealing on the road, this slip leads to a truly horrendous noise.
This may be occurring due to any number of factors, including the following:
Worn or Loose Belts
The main reason for belt squeal is that the belt is stretched or not tight enough on the pulley. Belt stretching can occur over time, making the tension between the pulleys and the belt less than optimal.
Belt wear and cracking, another common problem, can also cause tensions to become weakened. When a belt is not tight enough, it can easily slip on the pulley, creating that annoying squeal.
Contaminants on the Belt
Oil, grease, or other contaminants on the belt are very likely sources of slipping as the belt moves around the pulleys. There are usually various ways that such contaminants can find their way onto the belt. Common sources could be leaks from the engine or from somewhere else.
Misaligned Pulleys
Another common problem is a misalignment of pulleys, which can make a belt slip and squeal. Over time, bearings can wear. Improper installation can result in misalignment, or parts can be damaged.
Reasons for the Belt Squeal Goes Away When Accelerating
So when you hit the accelerator, the belt tightens, and that squeezes the slip for a while, and, bingo, the squealing stops. But, hey, listen to that belt! All this tension might make the underlying problem disappear for a while, but you’ll still have to do something about that slip.
Increased Tension
They might well tell you that, as you go faster, the belt tension goes up, which can temporarily stop the belt from slipping and squealing. That’s why motorists stop their car engines and slow cookers: it’s a short-term solution to a long-term problem.
Changes in Engine Load
Simply put, acceleration changes the load on the engine—and therefore, on those accessories tied in via the belt. This can smooth out the belt and pulley dynamics, reducing the chance of slipping and squealing.
Fixing Belt Squeal Goes Away When Accelerating
Inspect the Belts
Check the belts for cracks, fraying, and glazing. If they are compromised in any way, they should be replaced.
Inspect and Align Pulleys
Check that the pulleys are aligned. A misaligned or worn-out pulley should be repaired or replaced. Make sure that all the pulleys are arranged correctly. This will ensure that the belt does not slip on them.
Clean the Belts and Pulleys
Clean the belts and pulleys of contaminants. Vacuum or use an appropriate cleaner to remove oil, grease, or other contaminants that might be causing slippage.
Check Belt Tension
Make sure the belts are tensioned properly. A belt that’s too loose or too tight, for example, will squeal; use a belt tension gauge to take the reading and adjust according to manufacturer recommendations.
Replace Worn Components
If worn, the belts, pulleys, or tensioners should be replaced. Only with new parts will the belt drive run smoothly and quietly.
Preventing Future Belt Squeal Goes Away When Accelerating
Regular Maintenance: Make it a habit to frequently inspect and maintain your belt system to prevent squealing, especially to check the tension, alignment, and condition of your belt.
Use Quality Parts: Use high-quality belts and pulleys for better performance and durability. Good parts won’t squeal due to wear and tear.
Address Engine Leaks: Patch any engine leaks that lead to dirty belts. Just as you’ve been keeping your clutch disc clean by hosing off its friction surface (see ‘Preventing clutch slippage’ and ‘Squealing sounds’ earlier), you don’t want to contaminate your engine belts with oil or grease if you can help it.
FAQs On Belt Squeal Goes Away When Accelerating
Is it safe to drive my car if the belt is squealing?
That squealing belt might sound okay to get you somewhere quickly, but it’s a warning of a problem that will worsen if you ignore it. The longer you drive the car, the more that belt and other components will degrade, and the more you’ll end up paying to correct the damage that results.
Can a squealing belt affect my car’s performance?
Yes, a squealing belt can affect your vehicle’s performance. Because the belt drives other components like the alternator, power steering pump, and air conditioning, an irritated belt may lead to deficient operation of these components, which in turn would lead to poor vehicle performance.
How often should I inspect my car’s belts?
Check the serpentine belt on your car every 6 months or 6,000 miles – whichever comes first. That way, you won’t end up with an unexpected failure because old age has set in.
What are the signs that a belt needs to be replaced?
A common feeling towards a belt that needs to be replaced: All of these are indicators that your belt is either physically ageing or losing strength. Repeat after me: there is no shame in replacing a belt!
Can I fix a squealing belt myself, or should I see a mechanic?
If you possess some knowledge of mechanics and the proper tools, you could check the belt and correct it if it’s squealing, but if you are not sure how to do it or you feel unsettled, you should go to a mechanic to make sure your problem is concerned and resolved.
Conclusion
Belt squeal that disappears when you accelerate is also not uncommon, and the cause could be a number of things, from worn or loose belts, pulleys that are not perfectly aligned, contaminants on the belts, foreign objects that are caught in the system, etc.
The squeal may subside when you accelerate, but if the cause is not addressed, you will have extra and unnecessary wear and tear on your system. Maintenance and the use of quality parts will help avoid belt squealing.
If the problem still is not resolved and you are not the mechanically inclined type, take your car to a professional.