Car Shakes When Accelerating But Not When Coasting

If you maintain your car properly and stick to the service schedules, there’s no reason that it should cause you trouble. But as it is a piece of machinery, anything can go wrong over the …

car shakes when accelerating

If you maintain your car properly and stick to the service schedules, there’s no reason that it should cause you trouble. But as it is a piece of machinery, anything can go wrong over the years and miles of service.

The majority of the drivers complain that their car shakes when accelerating but not when coasting. This is a very common concern, particularly among the owners of cars that have put on some mileage, and are used on rough terrains.

Before you start to worry or panic, we have shortlisted all the possible causes of a car shaking when accelerating but not when coasting, so go through this article and we’ll guide you how to get rid of this problem and get back to comfortable ways. 

Why does my car shake when Accelerating but not when Coasting?

There could be a plethora of reasons that could be causing you this problem, so let’s jump right into it;

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1 – Faulty CV Joints

CV joints are those parts that connect the transmission to the axle, it means these are necessary for your car to move. Apart from that, they also permit the shaft to rotate but not move along its axis.

If your car also shakes when accelerating but not when coasting, then most probably your car has bad CV joints, and it is the most common culprit behind this issue.

2 – Worn Out Engine Mounts

Engine mounts keep the engine secured in its place, while isolating it from the other parts. These mounts also ensure that the excessive vibrations don’t pass on to the car’s frame.

Over time and excessive usage, these mounts lose their integrity and start to wear off, causing the car to vibrate a lot during acceleration but not so much while coasting.

3 – Worn Out Tires

Another common reason behind your car shaking when accelerating could be those bad, worn out tires. Tires are the only parts of the car that come into contact with the road, and if they are worn out, not balanced properly, or have uneven tread wear, the car would not be stable and vibrate a lot, especially at high speeds. 

4 – Loose Wheel Bearing

Wheel bearings are supposed to secure the wheels in place, while allowing their friction-free movement at the same time. If the wheel bearings have gone loose or damaged due to cracks, the wheels would move freely deviating from their axis. 

This is also a very common reason behind a car shaking when accelerating, and a difficult one to diagnose.

5 – Leaky Vacuum

A faulty intake hose, or a cracked intake manifold gasket can cause a vacuum leak in the engine of your car. If you accelerate your car, it will have strong vibrations in the front of the frame, and especially you’d feel in the steering wheel. 

6 – Loose Lug Nuts

Lug nuts might not be on the top of your mind, but these are very crucial parts of your car’s suspension system and connect the hub of the wheel to the axle. If the lug nuts are not tightened with a torque screw or are too loose, the tires will vibrate, causing the car to shake when accelerating but not when coasting.

7 – Faulty Clutch Parts

A damaged or worn out pressure plate is a common culprit behind this complaint, and if you cannot find any other obvious problem in your car, suspect your clutch assembly.

If it’s a bad pressure plate, you will have to rev up harder than usual when accelerating because a worn-out pressure plate won’t send optimal torque to the flywheel and the car would shake a lot. 

8 – Bent Axle

If the axle of your car is bent, it would shake a lot when you try to accelerate and gain speed but not when coasting. It is a very common issue and occurs due to rough usage and wear & tear over time. 

9 – Damaged Suspension

If any part of your car’s suspension is damaged or has become faulty, your car would shake when accelerating but not when coasting. Most probably, bad status or shock absorbers cause this problem as they become saggy and fail to provide enough stability to the car at high speeds.

10 – Steering Assembly Issues

You control your car via the steering assembly and if any component becomes faulty, such as the U-joint or the rod, the car would shake at high speeds and tend to sway from the straight. If your car shakes when accelerating but not when coasting and also becomes unstable, the steering is most likely the culprit.

How to Fix It

This is what you can do to get rid of your car shaking at high speeds, remember that these are technical jobs and you’d require professional help for them; 

  1. Replace the CV joints – as these are the most common culprits and getting this problem fixed will get rid of vibrations at high speeds.
  2. Get your Engine Checked – it could be those faulty engine mounts or a vacuum leak causing your car to shake when accelerating but not when coasting.
  3. Fix the Wheel Bearings and Lug Nuts – replacing the wheel bearings is usually the permanent solution and gives you relief for a few years to come. Tightening the lug nuts could also fix the issue and save you from hefty monetary damage.
  4. Suspension and Steering Column Repairs – two of the most common components that can be the culprits behind your car shaking at high speeds. Replacing the shock absorbers or U-Joint can get rid of this issue.
  5. Replace old tires – It could simply be your old tires and getting new ones for your car could solve this problem, apart from improving the fuel economy and ride stability. 

Final Thoughts 

If your car shakes when accelerating but not when coasting, suspect a serious issue and don’t take it for granted. Apart from killing your ride comfort, it could cause a potential hazard on the road.

There could be many possible reasons behind that, as discussed, so it is advisable to not drive your car daily in that condition and head over to a workshop to get an expert opinion from a professional mechanic.