Whirring Noise When Starting Car: Why It Happens and How to Solve It?

What Makes the Whirring Noise When Starting a Car? 7 Reasons and Fixes

Let me tell you the detailed reasons and their solutions, one at a time.

1. Cracked Belts

Different engine components are connected via belts. For example, there are fan belts, timing belts, etc., in your car. These serpentine belts are made of rubber. Over time, they may become brittle due to excessive heat. Belt wear is also common in cars.

When the belts get brittle, they will develop cracks. The cracked part of the belt will make this whirring noise when spinning. As the spinning starts when you turn the car on, you will hear the whirring noise when starting the car. It may continue till you drive the car.

How to Solve This?

1. You need to visually inspect the belts for signs of cracks. If there are cracks, cut the belts loose and throw them out.
2. Install new belts in place, and the whirring noise should be gone.

2. Worn Camshaft or Crankshaft Bearings

A camshaft or crankshaft uses bearings to move freely. When the bearings are properly lubricated, there is no unusual noise from these components. But as the lubrications dry out over time, the bearings face more friction than usual.

As a result, the bearings start to wear. If this goes unchecked for a long time, the bearings will be worn. You will get a whirring noise from the camshaft or crankshaft when starting the car.

How to Fix This?

Crankshaft or camshaft bearings aren’t visible until the engine is opened. So, this is not a DIY task. You should take the car to a repair shop and get the worn bearings replaced.

It will cost about $200-$300 for the bearing replacement, including parts and labor.

3. Broken Radiator Fan

When the heated coolant reaches the radiator, the cool air from the radiator fan lowers the temperature. As a result, the coolant is able to absorb the heat from the engine again. Sometimes, the blades of the radiator fan can crack or break.

If this happens, the fan will lose its balance. It will create a whirring noise from the front of the engine.

How to Fix This?

Replacing the broken fan is the only solution here.

1. Use a screwdriver to remove the fan mount.
2. Then, take the broken fan out of the mount.
3. Install a new radiator fan into the mount. Then, assemble the mount into place.
4. Radiator fans can cost about $200-$400, depending on your vehicle brand or model.

4. Stuck Engine Valves:

Engine valves ensure air-fuel mixtures can enter the engine and the burnt gas can leave the combustion chamber. Over time, engine valves can get heavy with accumulated particles. As a result, the valves might open or close properly during every engine cycle.

It will create a whirring noise from the engine. The problem is you may not be able to identify the source of the noise unless you are familiar with the noise.

How to Fix This?

I suggest taking the car to a repair shop. They need to open the engine head to check the condition of the engine valves. If the valves are dirty and stuck, mechanics will clean them. It should cost about $300.

After cleaning the valves, you should use fuel additives to prevent the particle deposit. These additives are available at local car shops for under $50.

5. Low Transmission Fluid

After you start the car and engage the transmission, a whirring noise can appear. If this happens, the problem is probably with the transmission system. And the main reason here is low transmission fluid.

If you don’t check the level regularly, transmission components will face more friction and wear prematurely. As a result, you will hear the whirring noise from the car after starting.

How to Fix This?

1. Remove the fluid reservoir cap and take the dipstick out. Wipe off the remaining fluid from the dipstick, and then again insert it into the reservoir. 
2. Now again, take off the dipstick and check the fluid level. The dipstick might have Min and Max markings on it. Make sure the fluid level is close to the maximum mark.
3. If the fluid level is too low, top it off with new fluid. Turn the car on and engage the transmission. Wait for some time so that the fluid distributes evenly.

6. Faulty Power Steering Pump

Modern cars come with the power steering feature. The pump responsible for controlling the steering can be faulty sometimes. In that case, it won’t be able to steer the vehicle well. And you will get a whirring noise from the front of the car.

How to Fix This?

Take the car to a repair shop and get the power steering pump checked. Replace the pump if necessary. It will cost about $100 to $200, including parts and labor.

7. Worn Wheel Bearings

Bearings inside the wheel hub ensure the wheel can rotate smoothly. They are lubricated with grease to reduce friction. But as the lubrication dries out, metal balls inside the bearing wear due to friction.

Over time, the bearings start to create a whirring noise. This mostly happens after you start the car and drive it.

How to Fix This?

You need to remove the wheels first. Then, take the bearing out from the hub. Check the metal balls for signs of wear. If the balls are worn out, you need to replace the bearings. It will cost about $300 for one wheel.