What Causes a Clicking or Knocking Noise in the Dashboard?

“What causes a clicking or knocking noise in the dashboard, especially when starting the car?” is a popular query among new car owners.

It can result from several issues originating from your AC system, battery, or even your starter. In this article, our car team will reveal the causes of dashboard noises and the best solutions to fix this issue.

Why Is There a Clicking or Knocking Noise in the Dashboard?

There is a knocking or clicking noise in the dashboard because of a damaged relay, bad battery, malfunctioning heater fan, failed actuator, bad AC system, defective starter, or a broken dash cover. The intensity and frequency of the noise will depend on its cause.

Take note that it is safe to drive with clicking sounds coming from your dashboard. Most times, these clicking sounds arise from small issues that are easy to fix. However, it’s still advisable to troubleshoot the problem and fix it as soon as possible.

– Faulty/Damaged Relay

A faulty or damaged relay will cause clicking noises in your car. The relay (also called starter relay) is a small switch that transmits power from the battery to the starter. If the relay is bad or faulty, it will trigger a single loud clicking sound, especially when starting your car.

A damaged or faulty relay will also make your car have a hard start. Sometimes, a blown fuse, corroded terminals, or wrong connection can make a relay malfunction or fail.

– Blend Door Actuator Problems

A faulty blend door actuator can cause knocking/clicking sounds in your car. The blend door (also called vent door or air-mix door) mixes cool and warm air together before sending them to your vents. The blend door regulator/actuator is the electric device that controls the blend/vent doors.

Sometimes, the actuator of the vent door can get stuck. When this happens, you may notice a clicking sound coming from your dash as the actuator tries to move the doors. Sometimes, it can even break down completely.

– Rod Knock

A rod knock can also cause your car dashboard to produce clicking sounds. A rod knock is a sound that you hear when any of the connecting rods of your vehicle knocks against the crank in the crankcase. This situation usually arises when the bearing connected to the rod has worn out or become damaged.

– Compressor Cycling/Fluctuating

A cycling/fluctuating compressor can also cause clicking noises in your car. Sometimes, this process (called short cycling) can go unnoticed, but you will often hear noises as the compressor cycles on and off. This situation often happens when your AC system overheats (due to low or no refrigerant), but it can also occur when there is a leak in the compressor.

– AC System Issues

AC system issues can also cause knocking/clicking sounds in your car. If you find your car making clicking/ticking noises whenever you turn on the AC, then your AC is likely the cause. The issue could be a worn-out clutch, low refrigerant level, or clogged condensate drain pipes.

Other times (especially when there’s a knocking sound), it’s loose mounts that are responsible.Generally, if your car AC unit struggles to function as it should, it’ll cause annoying clicking sounds.

– Problems With HVAC Controller Settings

If there are problems with the controller settings of your car’s HVAC system, you may hear clicking sounds coming from your dashboard. The HVAC, also known as the heating, ventilation, and air conditioning system, controls the temperature and air quality inside your car.

If this system isn’t calibrated, strange noises will come from your dashboard. An uncalibrated HVAC system will give false readings of various mechanical parts (like the blower motor), and this will cause clicking in the dashboard.

– Loose/Broken Dash Cover

A loose or broken dash cover can also be the cause of noises coming from your dashboard. As you drive your car, any loose or broken parts of your dashboard will begin to rub against other components in your dash, causing annoying sounds.

– Bad/Faulty Starter

A bad/faulty starter can also cause knocking/clicking sounds to come from your vehicle. A starter is a unique car component that delivers power to your engine to start your vehicle. When your starter is bad or faulty, you’ll most likely hear a single loud click (not multiple clicks) anytime you attempt to start your car. A bad starter will also cause your car to have a hard time starting.
Usually, starters wear out after 40,000 – 200,000 miles of driving. You may begin to experience clicking sounds and starting problems after crossing this threshold.

– Faulty Fan or Blower Motor

A faulty fan or blower motor (commonly called a heater motor) can also cause the clicking/ticking noise issue in your car. The blower motor is an important component that works with AC units. The blower motor powers the fan, which then pushes hot or cold air through the dashboard vents to control the climate in your car.

The blower motor has lots of moving parts. If any of the parts get worn out or damaged, they cause loud knocking noises. Also, a broken or loose-hanging fan can make noises. If you only hear noises while adjusting the fan settings of your car, then you should check your fan and blower motor.

– Dead/Faulty Battery

A damaged or faulty battery will cause clicking sounds in your car. Usually, when the battery is to blame, you’ll hear rapid clicking sounds when starting your car. This could be a sign that your car battery is old or dead.
Sometimes the fault may not be a dead battery, but corroded connection terminals or burnt wires.

– Bad/Faulty Alternator

A bad or faulty alternator can also be responsible for the clicking/knocking sounds you hear in your car. The role of the alternator is to generate electric power for your vehicle and to charge your battery. If your alternator is faulty, it will fail to charge the battery, and you’ll hear clicking sounds when trying to start your car. Another common sign of a bad alternator is engine misfiring.

– Stepper Motor Problems

A faulty stepper motor (also called a stepping motor) can cause clicking sounds to come from your dash. Stepper/stepping motors perform several functions in vehicles, and they’re usually attached to air-mix doors. If any of the stepping motors in a car fail to work, they’ll cause clicking sounds.

– Low or No Oil

Having low or no oil in your car can cause clicking or ticking noises. This noise happens due to a lack of lubrication. It can also occur when you use dirty oil. If you discover that your oil gets used up quickly, it’s possible you may have a leak somewhere.

What Are the Ways To Fix Clicking or Knocking Noise in the Dashboard?

You can fix a clicking or knocking noise in the dashboard by first identifying the source of the noise. Then, you can replace your dashboard, change bad relays, turn off the air conditioner or heater, replace the starter, top up or change your oil, or replace the battery.

– Check the Vent Doors

Check your blend door actuators for any damages. If you find any damage, replace them and test drive your car to see if the noises continue. Sometimes, the vent doors may only be stuck, not damaged. If so, free them.

– Check Oil

Check if your car oil level is low or if the oil is dirty. If the oil level is low, top your engine with oil, and if it’s dirty, change the oil. Also, check your oil filter to see if it needs changing or cleaning. If the noises in your car are indirectly caused by oil problems, carrying out these steps will solve the issue.

– Calibrate the Blower Motor

Recalibrating your blower motor can stop the clicking sounds coming from your dash. To do this, you need a bidirectional scan tool. If you don’t have one or you don’t know how to use it, see a mechanic to help you.

– Check for Bad Relays

Checking and replacing bad relays will solve your clicking/ticking noise issue. Most times, the fault with relays is a bad fuse. You can always test or replace your relays yourself (for most cars, relays are located in the fuse box under the hood).

However, the testing process is a bit complicated, so you may need to have a mechanic do it for you. It is advisable to replace your car starter relays after driving for 100 miles.

– Replace the Dashboard

Replace the dashboard of your car if it’s old/worn out. Doing this will stop any clicking/rattling noises that your dashboard may be causing. However, if your dashboard is simply unhinged, you may not have to replace it. Tightening a few loose screws will fix the issue.

– Turn off the AC Unit

If your AC system causes the clicking sound, switching off your air conditioning will solve the problem. However, this is only a temporary solution. You will need to see a mechanic to get your AC system properly checked and serviced.

– Check and Change the Battery

Test your battery to see if it still holds a charge. Look for any signs of corrosion at the terminals, and use a suitable tool to remove any rust that you find. If the damage is too severe or if your battery appears to be dead, replace it.

– Check Alternator

If your battery is okay and the terminals are not corroded, then your alternator may be to blame. Check if the alternator of your car is worn out and replace it. See a mechanic if you can’t replace the alternator yourself.

– Check Starter and Replace if Necessary

Replacing the starter will stop your car’s clicking noises and also stop hard starting. However, sometimes if your car makes clicking noises while refusing to start, tap the starter a few times and try starting the car again. It should start nicely. If it does not start, replace the starter.

– Check the Stepper Motor

Remove your dash and check if any object is obstructing the stepper/stepping motor. If it is, remove the object. However, if nothing is obstructing it, you may have to replace it.
Most stepping motors are located at the near end of the dashboard. If you can’t locate yours, see a mechanic.

Conclusion

Now you know what causes a clicking or knocking noise in the dashboard of your car and how to fix it, so let’s go over the major points one more time:

• The main causes of clicking noises are a faulty AC system, a bad relay, and battery/alternator problems.
• Other things like a broken dashboard, faulty car starters, faulty fans, and bad stepper motors can equally cause this issue.
• Stopping the clicking noise in your car involves locating the component that is responsible and fixing or replacing it as necessary.
• If you can’t trace the source of the sound, hire a mechanic to help you out.

You can follow the guide in this article and troubleshoot the cause of your clicking noise to fix it accordingly. If the problem seems to be from the engine (for instance, a rod knock issue), see a mechanic to get a repair done. It is best for a mechanic to check delicate issues like fixing rod knocks and testing batteries and relays.