4 Causes of a Screeching Noise When Accelerating
A strange noise can quickly ruin a trip. One of the most common, yet most annoying, irregular vehicle noises is a whistling or whistling noise when accelerating. In fact, there are many possible causes for strange noises when accelerating, and they usually require careful diagnosis. Read on to find out more.
Common Causes of a Screeching Noise When Accelerating
There are quite a few possible causes for a squealing car noise, many of which are heard by countless drivers every year. Here are some of the most common reasons why your vehicle may squeal when accelerating:
1. Internal gear problems
2. Worn alternator bearings
3. Damaged water pump bearings
4. Low power steering fluid level
5. A/C compressor failure
6. Tension/flex pulley issues
7. Dry, cracked, or slipping V-belt
8. Worn wheel bearings
Below we’ll take a closer look at each of the causes of vehicle squeals listed above. For convenience, we have grouped these causes into four categories:
#1 – Transmission Issues
Your vehicle’s transmission serves a very important function, being the key to distributing engine power to the drive axles in your car, truck, or SUV. Unfortunately, as transmissions age, they become more susceptible to internal failures.
In some cases, such a failure can result in an audible whistling noise. This type of noise is often difficult to pinpoint, especially when it comes from the vehicle’s transmission tunnel. A whining noise coming from your car’s transmission usually indicates that there is a problem with the fluid. It is very common to hear this kind of noise when the transmission fluid level drops beyond capacity or when the transmission oil pump starts to fail.
In addition, a torque converter failure can also cause a whining noise. Worn internal bearings can cause a buzzing sound when driving at high speeds that can be mistaken for a growling sound.
Severity
In most cases, the occurrence of a whining noise coming from your vehicle’s gearbox is considered very serious. If the torque converter is defective, the transmission must be removed for replacement.
The cost of such a repair is often expensive, usually exceeding $1,000. If a defective bottom bracket is causing the transmission to make noise, the associated repair costs are exponentially higher.
#2 – Worn bearings in belt-driven components
Vehicle engines are equipped with many belt-driven accessories. Each of these accessories uses a drive pulley and one or more sets of bearings. The V-belt transmits the rotational force of the crankshaft pulley to the pulleys of various belt-driven accessories. These accessories include the engine water pump, power steering pump, air conditioning compressor, and generators. In addition, this type of system also has tension and deflection rollers.
When the bearings of the above components start to fail, a squealing sound is often heard. Perhaps the most obvious example of this situation is a generator with a defective bearing. When these bearings fail, you may hear a loud whining or screeching noise in addition to the normal engine operating sounds.
Power steering pumps also tend to become very loud as they wear out. You can also expect such noises to occur if the power steering pump is low on fluid.
Severity
Failed power take-off components should also be diagnosed and replaced immediately. If such issues are not addressed, bearings can seize, belts can break, and you can ultimately be stranded on the road. Most modern vehicles rely on one belt to drive all associated accessories, so if one component is blocked, the rest of the vehicle’s belt-driven accessories can be inoperable.
#3 – The belt is dry, cracked, or slipping
As mentioned earlier, your vehicle’s V-belt drives numerous components that are essential to your vehicle’s operation. However, the belt can only drive these accessories if the belt is in optimal condition.
Over time, V-belts can dry out and develop cracks. As a result, the belt can no longer grip the pulleys of the various accessories it drives as efficiently as expected. This will inevitably result in belt slippage, which will increase in severity over time.
As the V-belt slides along the outside diameter of the various pulleys, the friction can create significant noise pollution. These noises are perhaps best described as a squealing noise that tends to increase with acceleration. This additional friction can cause further damage to an already worn V-belt, ultimately leading to failure.
Severity
In many cases, fan belt squeals and squeaks are more of a nuisance than anything else, with little risk of causing further problems if not addressed immediately. However, if the belt becomes badly worn or damaged, it can break or come off the pulley it runs on. When this happens, the functionality of all belt-driven accessories is affected and eventually rendered ineffective.
#4 – Wheel Bearing Wear
Wheel bearings ensure that the wheels of your vehicle rotate freely while you are driving. These bearings are often housed within a one-piece hub and will need to be replaced when the bearings inside start to wear out.
Also, many older vehicles were equipped with separate wheel bearings that could be removed and filled with grease as needed. Unfortunately, wheel bearings, regardless of type, tend to wear out over time.
In most cases, when wheel bearings are badly worn, they will cause a droning noise while the driver is traveling down the road. This noise usually changes pitch as the vehicle accelerates. At high speeds, this noise is often reminiscent of a whistling or whistling sound.
One can often pinpoint a faulty wheel bearing when cornering. If the sound in question changes pitch or ceases entirely in the middle of a turn, a vehicle’s wheel bearings become suspect.
Severity
Excessively worn, or damaged wheel bearings should be replaced as soon as possible. A failure to do so will only lead to increased wear, further exacerbating the issue at hand.
Upon reaching a point of total failure, the rollers found within a wheel bearing’s cage can unseat and dislodge, creating a dangerous amount of free-play within a vehicle’s hub.
In the most extreme of cases, an exceedingly worn wheel bearing can cause a hub to rest free upon its spindle. This presents a dangerous situation, which can ultimately cause a wreck or severely damaged wheel-end components.
