Whining Noise When Revving Engine In Neutral: Causes, Diagnosis, And Solutions!

It can be concerning when you rev your car’s engine in neutral, and an unexpected, whining noise pierces the air. Engine noises can be an ominous sign, indicating underlying issues that demand immediate attention.

So, what causes whining noise when revving the engine in neutral?

Various things, including worn-out or loose belts, a broken power steering system, alternator issues, and a broken water pump, can cause this strange noise.

Identifying the specific cause is crucial for implementing the right solution and preventing further damage to your vehicle. Continue reading to understand why your engine whines when you crank it in neutral. I will also examine how to diagnose these causes and outline detailed solutions to help you eliminate this problem.

Potential Causes & Solution of Whining Noise When Revving Engine in Neutral

Here are the potential causes and step-by-step fixes for each problem discussed below.

1. Worn-out or Loose Belts

The alternator, power steering pump, and water pump are just a few of the many engine parts powered by belts. Belts tend to wear out, crack, or stretch over time, which reduces their performance and increases their noise level.

Solution:

Carefully inspect all the belts in the engine compartment, including the serpentine and timing belts. Look for signs of wear, cracks, or looseness.

• If the belt is too loose, tighten it using a wrench or socket to change the tensioner pulley.
• If your vehicle has a belt tensioner, use a belt tensioner tool to release tension on the old belt.
• Compare the new belt with the old one to ensure they have the same length and width. Also, ensure the grooves on the new belt match the pulley configuration.
• Tighten the belt to the recommended tension measurement according to your car’s specifications.
• Start the engine and allow it to idle for a few minutes. Observe the new belt for proper alignment, tension, and unusual noise or movement.
• Turn off the engine and inspect the belt to remain properly positioned on the pulleys.

Cost:

Tightening or replacing a belt ranges from $20-$100, including parts and labor.

2. Faulty Power Steering System

The power steering system uses hydraulic pressure to assist with steering. Problems with the system can cause noise and make it difficult to maneuver the car. Problems like low power steering fluid or a failing pump may cause the whining noise.

Solution:

• Locate the power steering fluid reservoir in the engine compartment. It is usually marked with a cap labeled “Power Steering.”
• If the fluid level is below the minimum mark or appears dirty and contaminated, it may indicate a problem within the power steering system.
• Also, examine other parts, such as the hoses and power steering pump, for signs of leaks.
• Add the appropriate type of power steering fluid recommended by your vehicle’s manufacturer.
• If the fluid appears dirty or contaminated, it is advisable to have the entire system flushed and replaced with fresh fluid.
• Also, replace the hoses and the pump if damaged.

Cost:

The cost of replacing power steering fluid is relatively inexpensive, typically ranging from $20 to $50. However, if the system requires flushing or repairs, costs can range up to $200 or more, depending on the extent of the problem and parts/labor costs.

3. Faulty Alternator

Alternators have bearings that enable the smooth rotation of their internal parts. These bearings may deteriorate or break down over time, increasing friction and vibration.

When the alternator spins, worn-out bearings can produce resistance and an audible whining sound. You may also notice that the EPC light goes off when engine starts.

Solution:

It is advised to replace the entire alternator if worn bearings cause a whining sound. This is because the bearings are a crucial component of the alternator’s internal parts and are difficult to replace separately.

• Open the hood and disconnect the battery’s negative terminal to prevent electrical shock.
• Locate the drive belt that connects the alternator to the engine. Use a wrench or socket set to loosen the tensioner pulley, release the tension, and remove the drive belt.
• Identify and disconnect the electrical connections attached to the alternator, such as the main power cable and the voltage regulator plug.
• Locate the mounting bolts securing the alternator to the engine or mounting bracket.
• Use a wrench or socket set to remove these mounting bolts, taking care not to damage any surrounding components.
• Once the alternator is out, position the new alternator in place, aligning it with the mounting holes.
• Insert and tighten the mounting bolts by hand to secure the alternator in position.
• Reconnect the electrical connections to the appropriate terminals, ensuring they are securely attached. Also, reinstall the drive belt.
• Start the engine and listen for any unusual noises.

Cost:

The cost of a replacement alternator range from $750 to $845, including parts and labor. These costs depend on the complexity of the procedure and labor rates in your area.

4. Faulty Water Pump

The water pump is responsible for circulating coolant throughout the engine to maintain proper temperature regulation. When the water pump malfunctions, it can result in a whining noise and various cooling system problems.

Look for any additional indications of a bad water pump, including engine overheating, coolant leaks, or steam coming from the engine.

Solution:

• Locate the coolant drain plug or radiator drain valve at the bottom of the radiator. Place a drain pan underneath to catch the coolant.
• Open the drain plug or valve and let the coolant flow into the drain pan until the radiator is fully drained.
• Identify the drive belt or belts connected to the water pump and remove them from the engine compartment.
• Locate the water pump and its mounting bolts and remove them. Disconnect any hoses or coolant lines attached to the water pump.
• Position the new water pump in place, aligning it with the mounting holes. Reconnect the hoses, coolant lines, and drive belts to the appropriate fittings on the new pump, ensuring they are securely attached.
• Follow the manufacturer’s instructions to refill the cooling system with the recommended coolant. Fill it properly and bleed any air from the system as necessary.

Costs:

Depending on the model of your car, a replacement water pump may cost $100 to $200. Depending on the difficulty of the procedure and local labor costs, the labor cost for replacing a water pump range from $200 to $500.

5. Transmission Issues

Transmission is essential in transferring power from the engine to the wheels to enable seamless gear changes and effective vehicle operation.

When issues with the transmission arise, they may be audible as strange noises, such as a whining sound. These issues include low transmission fluid or a clogged fluid line/filter.

Solution:

Locate the transmission fluid dipstick and remove it to inspect its level and condition. Wipe the dipstick thoroughly and insert the dipstick back into the tube to see the fluid level.

The fluid level should fall within the designated “full” or “proper” range. You must add more if the level is below the “proper” range. You may wonder, “Does a broken dipstick do damage to an engine?” no, it does not cause engine damage. However, you won’t measure the fluid level accurately.

Also, inspect the transmission’s fluid lines that connect to the radiator or transmission cooler. Keep an eye out for any signs of damage or leakage. Do the same for the fluid filter.

• Slowly pour the recommended transmission fluid into the funnel as specified in your vehicle’s owner’s manual.
• Check the fluid level periodically using the dipstick to prevent overfilling. Add fluid gradually until it reaches the proper range.
• If the transmission filter or fluid line is damaged, I recommend letting a professional do this repair. It is not a difficult task, but it can get messy if you do not have enough experience.

People Also Ask

The following are questions I found most people asking about this topic.

Conclusion

Whining noise when revving the engine in neutral is a concerning symptom that indicates an underlying issue within the vehicle. By understanding the noise characteristics and conducting proper diagnostic procedures, vehicle owners can determine the source and decide on the appropriate action.

Preventive measures like regular engine maintenance and timely inspections and repairs can help vehicle owners avoid the whining noise. By taking proactive steps, vehicle owners can maintain the performance of their engines, ensuring a smooth and quiet driving experience.