How do I know if my Honda Civic motor mount is bad?

If your Honda Civic is experiencing unusual vibrations, shaking, or noises while driving, it may be a sign of a bad motor mount. Motor mounts are essential components that secure the engine to the vehicle's frame, and when they wear out, it can lead to various issues. In this article, we'll explore the signs of a bad motor mount in a Honda Civic and provide steps to diagnose and address the problem.

Signs of a Bad Motor Mount

Here are some common indicators that your Honda Civic's motor mount may be failing:

• Excessive Vibrations: If you notice increased vibrations or shaking while the engine is running, especially at idle or during acceleration, it could be a sign of a worn-out motor mount.


• Clunking or Banging Noises: When the motor mount is failing, you may hear clunking or banging sounds, particularly when accelerating or decelerating.


• Engine Movement: If you observe the engine moving excessively or shifting position, it's a clear indication that the motor mount is no longer effectively securing the engine in place.


• Uneven Tire Wear: A bad motor mount can cause the engine to shift, leading to uneven tire wear, especially on the front tires.

If you notice any of these symptoms, it's essential to have your Honda Civic's motor mounts inspected and replaced if necessary.

Diagnosing a Bad Motor Mount

To diagnose a bad motor mount, you can follow these steps:

• Visual Inspection: Carefully inspect the motor mounts for any signs of cracking, splitting, or deterioration. Look for any visible damage or excessive wear.


• Engine Movement Test: With the engine running, try to manually move the engine by pushing or pulling on it. If the engine moves excessively, it's a sign of a bad motor mount.


• Bounce Test: Turn off the engine and apply pressure to the front of the vehicle, then release it. If the vehicle bounces excessively, it could indicate a problem with the motor mounts.


• Listen for Noises: Start the engine and listen for any unusual noises, such as clunking or banging, that may indicate a failing motor mount.

If the motor mounts are found to be faulty, it's essential to replace them as soon as possible to prevent further damage to the engine or other components.

Replacing the Motor Mounts

Replacing the motor mounts on a Honda Civic is a relatively straightforward process, but it's recommended to have a professional mechanic perform the work to ensure it's done correctly. The cost of replacing the motor mounts can vary depending on the specific model and labor costs, but it's generally an affordable repair.

By being aware of the signs of a bad motor mount and taking the necessary steps to diagnose and address the issue, you can help maintain the overall health and performance of your Honda Civic.

What are the symptoms of a bad motor mount?

Symptoms of bad motor mounts include excessive vibrations and shaking, especially at idle or when shifting gears, as well as clunking, thudding, or banging noises from the engine bay when the vehicle is started, stopped, or accelerated. Other signs are noticeable engine movement when shifting into drive or reverse and a bumpy ride, where the engine can be seen to visibly rock or move more than usual.
 
Vibration and shaking 

• Excessive vibration: You will feel excessive shaking, especially at idle, in the steering wheel, or through the vehicle's floorboards. 
• Vibration when shifting: A noticeable jolt, thud, or vibration when shifting into reverse or drive is a classic sign. 
• Jerking: The car may feel like it jerks or lurches when starting, shutting down, or accelerating, particularly from torque changes. 

Noise

• Clunking or banging: You might hear a loud clunk or bang, especially when putting the transmission into gear or when accelerating from a stop. 
• Thudding: A thud from the engine bay, particularly on startup or shutdown, can indicate a problem. 

Engine movement

• Visible engine movement: The engine can be seen to move, rock, or sway more than normal, particularly when accelerating or shifting gears. 
• Unsafe cornering: In severe cases, a broken mount can allow the engine to swing excessively during turns, creating a wobbling sensation and unsafe cornering. 

Other symptoms

• Fluid leaks: Some fluid-filled mounts may leak, indicating they have failed. 
• Loose parts: The excessive vibration can cause other components like hoses and fasteners to loosen over time. 

Will bad motor mounts throw a code?

Yes, bad engine mounts can throw a code, especially in modern vehicles with electronic or hydraulic mounts that communicate with the car's computer. They can also cause a code indirectly if excessive engine vibration triggers other sensors, such as a knock sensor. 
This video explains how engine mounts can trigger a code: 58sMotorCarNutYouTube · Apr 17, 2025
Direct causes

• Electronic/hydraulic mounts: Many modern cars use mounts that have a sensor and are controlled by the car's computer to adjust stiffness for different driving conditions. A failure in this system will trigger a code. 
• Specific designs: Some vehicles, like certain Volvos, have vacuum-controlled mounts that can cause a check engine light if they fail. 

Indirect causes

• Vibration triggering other sensors: If a mount fails, the engine can vibrate excessively against the subframe. This vibration can be so severe that it falsely triggers other sensors, most commonly a knock sensor, leading to a code. 
• Damage to nearby components: Extreme movement from a failed mount could cause stress on nearby wiring or sensors, leading to a malfunction and a code. 

This video explains how a bad engine mount can cause a knock sensor code: 49sNiX FiXYouTube · Oct 6, 2023
What to do

• Don't ignore the code: If you get a code related to your engine mounts, it's a real issue that needs to be addressed. 
• Scan for codes: Have the codes scanned to determine the exact issue. The scan tool will provide specific codes related to the mounts or other sensors. 
• Inspect the mounts: Check the mounts for physical signs of damage like cracking, leaks (for hydraulic mounts), or separation. 
• Consult a mechanic: A professional can properly diagnose the problem and replace the mounts or address any other related issues. 

How to tell if mounts are causing engine movement?

With a decently running vehicle you should only feel slight vibration. If it's vibrating really hard when you crank it up, especially cold, it's likely a bad motor mount. The mount should be easily visible on the passenger side, it might be under a coolant reservoir but you should inspect the rubber.

How do you know if your motor mounts are bad Honda Civic?

A bad motor mount may show no immediate noise or vibration but can cause engine movement during acceleration. Inspect mounts for cracks, tears, or excessive play by visually checking and gently rocking the engine. If mounts appear intact and engine remains stable when revved, replacement may be unnecessary.