7 Easy ways to get rid of engine noise in car stereo?

Written by: Miles Walker
Last Updated on:
How to get rid of engine noise in car stereo

Engine noise in your car stereo typically sounds like a whining that increases with engine RPM.

How to get rid of engine noise in car stereo

1. Check Connections and Grounding:

  • Loose or faulty ground connections are a common culprit. Ensure the stereo ground cable is securely fastened to bare metal on the car chassis, not just any painted surface. Clean the contact point for a better connection.
  • Inspect all other wiring connections for tightness and damage.

2. Isolate the Amplifier (if you have one):

  • With the engine running and volume low, disconnect the RCA cables from the amplifier. If the noise disappears, the issue likely lies with the RCA cables or the amplifier itself.

3. Test the RCA Cables:

  • Try high-quality RCA cables and ensure they’re not routed near power cables.
  • You can temporarily run them outside the car to see if interference improves.

4. Check your car stereo ground wire

If your stereo’s ground wire is not properly connected to your car’s chassis, it can pick up interference from the engine.

First, disconnect your stereo’s ground wire from the chassis to check your ground connection. Then turn on your car stereo and see if the noise goes away. If it does, your ground wire is not properly connected, and you’ll need to fix it.

There are a few different ways to do this. One is to use a self-tapping screw to make a new hole in the metal of your car’s chassis. Then, use a wire brush to clean off any paint or rust around the hole. Finally, screw the ground wire into the hole.

Another option is to use a grounding block. This is a small piece of metal that you can attach to your car’s chassis using screws or bolts. The ground wire then attaches to the grounding block.

If you’re not sure how to do this yourself, you can always take your car to a professional stereo installer, and they’ll be able to help you out.

5. Use a sound deadening mat

If you still can’t get rid of the engine noise, you might want to try using a sound deadening mat. You can place these special mats under your car stereo speakers. They help to absorb vibrations and reduce noise.

You can find sound deadening mats at most auto parts stores. Just make sure to get those specifically designed for use in cars.

Installing a sound deadening mat is usually pretty simple. Just peel off the backing and stick the mat in place. But if you’re not sure how to do it, you can always ask a salesperson for help.

Engine noise in car stereos can be extremely frustrating. But by following these steps, you should be able to reduce or eliminate it.

6. Pulling Out the Stereo

The most effective way to reduce engine noise in your car stereo is to physically remove the stereo unit from the car. This will allow you to access the back of the stereo and disconnect the ground wire. Once the ground wire is disconnected, the engine noise should be significantly reduced.

If you cannot remove the stereo unit from the car, you can try to disconnect the ground wire at the back of the stereo. This may not be as effective as removing the stereo unit, but it will still help to reduce engine noise.

7. Turning off all functions of the sound system and unplugging the speakers

The last way to get rid of engine noise in your car stereo is to turn off all functions of the sound system and unplug the speakers. This will allow the sound system to reset and the engine noise should be gone. If you want to completely disable your sound system, you’ll need to unplug the speakers and disconnect the speaker wires. Applying Mu-metal shielding around the wires will ensure that no sound gets through.

8. Other Checks:

  • If you have an amplifier, ensure the gain isn’t set too high. This can amplify electrical noise.
  • A faulty head unit or alternator can also cause noise. If the above steps don’t solve it, consider seeking help from a car audio professional.

Diagnose the Culprit with RCA Cable Testing

Engine noise can be a major buzzkill for your car audio experience. But before you rip apart your dash, here’s a simple guide to identify if your RCA cables are the problem.

Warning: This process requires the engine to be running, so ensure it’s performed in a well-ventilated area.

Step 1: Silence the System

With the engine on, completely mute the volume on your head unit.

Step 2: Crank Up the Amplifier (Temporarily)

Increase the gain on your amplifier until you hear a faint alternator whine. This is normal engine noise being amplified.

Step 3: Isolate the Amplifier

Disconnect all RCA cables from the amplifier. If the whine disappears, the issue lies before the amp, potentially with the RCA cables or head unit (proceed to Step 4). If the whine persists, the problem is likely with the amplifier or power cables (skip to Step 8).

Step 4: Narrowing Down the Source

Reconnect the RCA cables to the amplifier. Now, unplug them from the head unit. If the whine is gone, the culprit is the RCA cables (Step 6). If the whine remains, the head unit might be faulty (Step 7).

Step 5: Cable Placement?

If your RCA cables are suspected, remove them from the car entirely. With the engine running, reconnect them to the head unit, run them loosely across the carpeted floor, and then plug them back into the amplifier. Does the whine vanish? If so, the placement of the RCA cables is likely to blame.

RCA Cable Rerouting

Engine noise can be induced into RCA cables if they run too close to power wires or the vehicle’s body. To fix this:

  • Reroute the RCA cables on the opposite side of the car from the power wires.
  • Maintain a safe distance from any antennas or antenna cables.
  • Avoid running the cables directly on the car’s metal frame. Instead, position them between the carpet and padding for better shielding.

If the whine persists after rerouting, consider using a new set of RCA cables in Step 6.

Step 6: Upgrading Your RCA Cables

Repeat Step 5 with a different, preferably higher quality set of RCA cables. Higher quality cables often have better shielding to reduce noise interference and can also improve overall sound quality.

Step 7: Head Unit Woes

If even new cables don’t eliminate the whine, your head unit might be malfunctioning. Consult a car audio professional for further diagnosis and repair options.

Step 8: Beyond the RCA Cables

If disconnecting the RCA cables in Step 3 didn’t solve the issue, the problem likely lies with your amplifier or power cables. This troubleshooting requires further investigation by a car audio expert.

Pro Tip: Browse through our RCA cable catalog: insert link here to find high-quality cables with superior shielding to optimize your car audio system’s performance.

Fixing Engine noise in Car Stereo using Using an inline Power filter

An inline power filter can definitely help reduce engine noise in your car stereo, specifically the type of noise called alternator whine. Here’s how to install one:

Things you’ll need:

  • Inline noise filter with a current rating that matches your stereo’s fuse (usually 15-30 amps)
  • Wire strippers/cutters
  • Electrical tape (optional)
  • Basic socket wrench set (depending on how you access your stereo’s power wires)

Step 1: Locate the power wire

Identify the constant 12v power wire (usually red) going to your car stereo. This might be behind the dash, connected to the stereo itself, or near the fuse box depending on your car. Consult your car’s wiring diagram if needed.

Step 2: Disconnect the battery

Safety first! Disconnect the negative terminal of your car battery to avoid electrical shorts.

Step 3: Prepare the power wire

Carefully strip about 1/2 inch of insulation from the constant power wire.

Step 4: Install the noise filter

Most inline filters have two terminals, labelled “Input” and “Output”. Connect the stripped end of the power wire to the “Input” terminal of the filter using the appropriate connector (usually a crimp connector). Tighten the screw securely with a small wrench.

Step 5: Connect the output to the stereo

The filter will have another wire coming out, labelled “Output”. Attach this wire (using another connector) to the remaining un-cut section of the constant power wire going to your stereo.

Step 6: Ground the filter (optional)

Some filters recommend grounding the metal casing to the chassis for additional noise reduction. You can do this by finding a clean, bare metal spot on the car’s chassis and screwing the filter’s ground wire there using a grounding lug (purchased separately).

Step 7: Double-check and insulate

Make sure all connections are tight and secure. Optionally, you can wrap the connections with electrical tape for additional insulation.

Step 8: Reconnect the battery

Reconnect the negative terminal of your car battery.

Step 9: Test the system

Turn on your car stereo and see if the engine noise has been reduced.

Additional tips:

  • Running the power cable and RCA cables on opposite sides of the car can also help reduce noise interference.
  • If the noise filter doesn’t completely eliminate the engine noise, consult a car audio professional for further troubleshooting. They might recommend checking the ground connection of your head unit or other solutions.


Why does my radio whine when I accelerate?

The whine you hear is likely caused by electrical interference from your car’s alternator. This alternator whine is most common with aftermarket radios or sound systems, but it can happen with factory setups too.

Here’s a quick rundown of why it happens:

  • Alternator generates electrical current for your car.
  • Imperfect grounding or wiring issues can cause alternator’s electrical noise to leak into the audio system.
  • This noise is then amplified by the radio and played through the speakers as a whine.

The whine usually gets louder or higher-pitched as you accelerate because the alternator spins faster to meet the car’s electrical demands.

How do I turn off the ignition noise in my radio?

You can’t completely turn off ignition noise, but here are some ways to reduce it:

  • Grounding: Make sure your radio has a good ground connection. This is usually a black wire on the radio harness. You can try cleaning the contact point and re-grounding to bare metal on the chassis.
  • Noise Filter: Install an ignition noise filter on the power cable going to your radio. This small device filters out the electrical noise before it reaches the radio.
  • Check Antenna: Ensure your antenna is properly connected and free of corrosion. A loose or damaged antenna can pick up more electrical interference.

How do you get rid of the alternator whine on the radio?

If your car’s alternator is whining, it’s not charging the battery properly. You might be able to fix the problem by cleaning the battery terminals and replacing the spark plugs. If that doesn’t work, you might need to replace the alternator.

How do I stop my alternator from making noise in my stereo?

The noise you’re hearing is likely alternator whine, caused by electrical interference from your alternator entering your stereo system. Here are two ways to tackle it:

  1. Noise Filter: Install a noise filter between your alternator and the battery, or inline on the power cable to your head unit. This filter blocks the electrical noise.
  2. Grounding: Check and improve grounding connections. Ensure the stereo unit has a good ground to the car chassis, separate from the battery ground.

What are the causes of engine noise in car stereos?

There are a few different reasons you might hear engine noise in your car stereo. It could be that the ground wire is loose, the head unit isn’t properly secured, or there’s interference from other electronic devices.

If the ground wire is loose, it can cause a buzzing sound that will be amplified through the speakers. To fix this, check the ground wire and make sure it’s tight.

If the head unit isn’t properly secured, it can also cause buzzing or rattling sounds. Ensure that the unit is tightly screwed in place and that there’s no movement.

Lastly, interference from other electronic devices can also cause engine noise. If you have a phone or other device plugged into the head unit, try unplugging it and see if that makes a difference.

How to maintain your car stereo and continue to run quietly without any engine noise?

You can do a few things to maintain your car stereo and keep it running quietly without any engine noise. First, make sure to keep the ground wire tight and secure. You should also regularly check that the head unit is tightly screwed.

If you have a phone or other device plugged into the head unit, unplug it when you’re not using it. Interference from other electronic devices can cause engine noise, so it’s best to avoid this.

Finally, if you’re still having trouble with engine noise, you can try using noise-canceling headphones while you’re driving. This way, you’ll be able to enjoy your music without any interference.

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I'm Miles Walker and I'm the founder of autoaudiolab.com I've been in the car audio industry for over 20 years and have a wealth of knowledge to offer on all things related to car audio. I graduated from UC Berkeley with an electrical engineering degree, so you can rely on me for top-notch expertise and advice when it comes to upgrading your sound system.

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