Engine Vibration When Decelerating: Know The Causes And Solutions

In-depth Discussion on Reasons for Engine Vibration When Decelerating

Now, let’s know the causes in detail and the step-by-step process of their fixes:

1.     Damaged Rotors And Brake Pads

Sometimes, extreme heat can cause damage to the rotors. As a result, when the brake pads touch the rotors, you will feel the vibration in your car. Moreover, wearing the brake pads will cause inefficient braking action. 

Besides, the insufficient connections between the engine and braking components will cause vibration in the engine. These issues may also arise when the brake pads get clogged with soil or dirt.

This will even cause shaking in the steering wheel and pulsation in the brake pedals. Also, the car will take more time to stop.

Solution:

If you find damaged rotors or brake pads, you need to replace the damaged ones.

Here are the steps:

• Step 1: Check if the brake pads or rotors have scratches or bents.
• Step 2: Remove the wheel to access the brake pads and rotors.
• Step 3: Detach the calipers, retaining clips, or pins, also removing the old brake pad and then the rotors.
• Step 4: Clean the hub surface and clogged rotors.
• Step 5: Install the clean rotor or new rotor and brake pad.

Replacement of brake pads and rotors will take around $250-$500 for each axle in professional shops.

To visualize this whole process, check this YouTube video:

2.     Defective Engine Mounts

Generally, the engine is connected to various parts of your car through mountings. Those mountings help to eliminate or reduce the vibration and shaking.

Hence, any damage or defects in those mountings will result in the engine vibration of your vehicle. Besides, you may experience unpleasant rattling noises while decelerating. Also, the engine will move excessively when you decelerate.

Solution:

To fix this issue, you must replace the defective engine mounts. With the engine off, look for visible damage, tears, or cracks on the engine mounts. Besides, examine if there are any leakages in the hydraulic engine mounts.

If found damaged, replace the defective engine mount by removing the old one.

Generally, you may need to spend around $446-$498 for replacing an engine mount. A simple rubber or steel mount costs up to $10-$150.

3.     Wear Or Unbalance In Tires

Unbalance in tires can cause premature aging, uneven tear, wear, and friction in the tires. Also, wearing tires will cause imbalance when you brake or slow down your vehicle. Generally, you may feel the vibrations through the steering wheel.

Solution:

To diagnose this issue, check the treads, and visible wear and tear on the tires. In this case, you need to replace the worn tire or balance the tires.

To replace the tires, first, jack up the car. Now, you need to remove the tires using lug nuts. Then, you have to install a tire. Generally, a set of 4 tires cost approximately $800-$1200.

To balance the tires, you will need a tire balancer. You may need to spend around $30-$100 to balance all four tires.

4.     Bad Joints

Generally, constant velocity joints(CV joints) are the connections between the wheel and transmission. The tie rod end joints attach the car’s wheels and steering wheel.

Moreover, axle joints are important for connecting the wheels with the car’s body. Hence, the higher the speed, the higher the vibration will be due to bad joints.

You can also notice greases inside of the wheels.  The steering will also get slippier if the reason for engine vibration is defective joints.

Solution

You need to detect the problematic joint and need to repair or replace it.

Since replacing the CV joint is a highly professional task, I would suggest you hire a professional mechanic.

Replacing a CV axle will cost $60-$150 for an axle shaft, and the labor cost will be around $150-$350. The average replacement cost to replace tie rod ends, along with the labor cost, will be $100-$400.

Check this video to understand the process better:

5.     Damaged Rims

If the rims get damaged, it will hamper the alignment of tires on the wheels. This will lead to wobbling if your car slows down. Besides, damaged rims may cause wear to the tires.

With this issue, you will have difficulty handling your car. Also, the fuel efficiency will decrease. Moreover, you can also hear thumping noises in the cabin of your car.

Solutions

If you find any symptoms of damaged rims, you can repair your bent rims or even replace them. In the case of steel rims, you can hammer back the rims into their right shape.

To replace the rims, follow these steps:

• Step 1: Remove the lug nuts from the wheel.
• Step 2: Break the seal between the tire and rim by slipping a screwdriver in between them. You need to push the screwdriver outward for this.
• Step 3: Detach the rims and tire from each other using a pry bar.
• Step 4: Install a new rim and tighten it onto the car’s wheel.

Replacing the rims will cost around $200-$500 for each wheel.

6.     Damaged Wheel Suspension

Wheel suspensions are for connecting the wheel with the vehicle. Hence, worn springs or damaged suspension will affect the car’s stability while decelerating.

That’s why the car may pull on one side when you slow down your car. Even the steering may act stuck in this case. The shock absorbers will also become excessively greasy or oily.

Solution

To replace the damaged wheel suspension, follow these steps:

• Step 1: Check which side of the car is sitting lower. The side has a broken suspension. Lift the vehicle on that side and remove the wheel.
• Step 2: Compress the spring using spring compression.
• Step 3: Remove the bolts at the bottom and above the shock or strut. Then, pull out the damaged rim.
• Step 4: Install the new rim and fasten the bolts, following the reverse process of removing them.

To understand the whole process better, check this YouTube video:

Generally, you need to spend around $1300 for the parts. Then, the labor cost for the replacement will be about $230-$300.

7.     Engine Misfires

Sometimes, the engine can misfire, which may cause engine vibration issues while decelerating. Generally, clogged air filters and spark plugs, improper fuel pressure, and leakage can cause this issue.

If the engine vibration occurs due to engine misfires, the engine will use more fuel. Also, sometimes, the engine may lose power when you slow down your car.

Solution

Here are the fixes for the engine misfiring:

• Step 1: Open the car’s hood and locate the air filter. Then, take out the air filter from its housing and clean it using a brush. After cleaning, reinstall the air filter in its position.
• Step 2: Detach the plug wire that goes to the spark plug. Using a socket, pull out the spark plug also.
• Step 3: If the spark plug is damaged, install a new spark plug. Then,  secure it in its position by fastening the nuts and pins. This will cost you around $66-$250.
• Step 4: To replace the fuel pressure regulator, you need to disconnect the battery first. Then, open the engine cover and disconnect the vacuum lines attached to the regulators. Now, pull out the defective regulator and install a new one. For this replacement, you may need to spend around $250-$500.
• Step 5: Fuel pressure can drop due to leakages in vacuum hoses. You need to repair or change those broken hoses.

FAQs

In this FAQs section, we will answer a few common questions about the wobbling of cars during deceleration.

Why Does My Car Vibrate Only While Decelerating From High Speed?

An unbalanced tire is the main reason for the vibration of your vehicle while slowing down from 50-60mph. Typically, faster tires cause extra friction, and the vibrations will also be intense. Thus, the unbalanced tires may not create vibration issues at low speeds.

What Is The Fix For Clunking And Harsh Vibration While Decelerating?

When there is a clunking noise with hash vibration, most transmission mounts are the reason. To fix this, you need to change the transmission motor mounts. Besides, you can try replacing the flywheel and clutch.

Why Does My Car Vibrate While Decelerating When Going Downhill?

This primarily occurs if your vehicle’s driveshaft has free play. When there is no free play, the problem can be the clogged EGR valve. Otherwise, a damaged driveshaft is responsible for causing the vibration issue.

Conclusion

Generally, defective engine mounts, joints, brake pads, rotors, wheel suspensions, and rims cause engine vibration when decelerating. Besides, engine misfires and worn-out or imbalanced tires can also cause this issue.

Sometimes, you may experience rattling noises with harsh vibrations when you try to slow down the vehicle. To fix the vibration issue, you need to fix or replace the damaged components of your car. If you don’t have the proper skills to perform these complex tasks, you better seek professional help.