Anything other than a quiet, smooth ride from your car can often be cause for alarm. The reality is that there are many different causes for juddering, from engine faults to brake and suspension issues. 

In this article I cover some of the most common causes of cars' juddering and how they are usually remedied, as well as how severe of a problem they can become. 

Why Does My Car Judder When Driving?

Juddering when driving can be a symptom of a few different problems, but regardless of the cause, it can be disconcerting, to say the least, especially as some causes can get worse with speed. These are the two most common reasons:

1. Engine Misfiring

If your engine isn’t running smoothly, it can translate to a juddering or shaky ride, whether whilst accelerating or cruising at a constant speed. Engine misfires, often caused by old spark plugs, a clogged mass air flow sensor or a failing coil pack can cause this.

Misfiring can also lead to engines sounding lumpy at idle, or stalling and cutting out when slowing and stopping, such as approaching a junction.

2. Wheel Imbalance

When tyres are fitted, the technician will use a balancing machine to add lead weights to counteract irregularities in the tyre and the weight of the valve, making them perfectly balanced. However, the weights are usually only stuck on and can fall off.

At 70mph your wheels rotate around 16 times per second, this means any imbalance in them can transfer directly to the car via the suspension, the vibration will get worse at speed and may even cause your steering wheel to wobble slightly.

Why Does My Car Judder When Braking?

Any unusual noises or vibrations are even more concerning if they happen whilst braking, as they may indicate an issue specifically with your brakes, these are some possible causes.

1. Warped Brake Discs

All modern cars have disc brakes on the front wheels, these use a flat disc and two pads to absorb energy and slow down the vehicle. If your brake discs are particularly old or have been used heavily - such as during a long downhill stretch - they can warp. 

Once warped, the discs will cause a vibration that transmits through the car's suspension and will be easily felt by any passengers in the car, even more so through the brake pedal itself.

Juddering or vibration from warped brake discs will feel more harsh, with a higher frequency at higher speeds, and vice versa. 

2. Worn Track Rod Ends

As an integral part of a car's suspension and steering system, the track rod ends connect the steering rack to the wheel hubs, allowing steering input to be transmitted to the wheels. 

Track rod ends use a ball and socket type joint to allow for movement in the suspension, these wear out over time. This can cause both a knocking noise when going over bumps, and vibration under heavy braking.

Why Does My Car Judder When Idling?

1. Broken Dual-Mass Flywheel (DMF)

The flywheel is a key component that smoothes out the power delivery of an engine, a dual mass flywheel is in effect a more complex flywheel with multiple moving parts, that helps even further to reduce the level of vibration transmitted to the gearbox and therefore the car. 

Through normal use the springs and mechanisms in the DMF become worn, and reduce the effectiveness of the overall assembly. This leads to a significant increase in vibration felt in the car and through the clutch pedal.

2. Worn Engine Mounts

All engines create vibrations, these are isolated from the body of the car via rubber-cored engine mounts, which absorb and dampen the vibrations. Over time, the heat and vibration from the engine can deteriorate these mounts, reducing their effectiveness. 

If your engine mounts are really bad, they can cause noticeable juddering or shaking of the car, this will be most noticeable when idling, changing gear or pulling away from a standstill.

How To Repair Car Juddering Issues

The issues listed above can seem daunting, but most can be fixed with the replacement of a few parts, though some will require more labour costs than others. 

Fixing Juddering Whilst Driving or Accelerating

If your engine seems to be stuttering, misfiring or ‘breaking up’, then the replacement of the following components should be the first port of call:

• Spark plugs
• Air filter
• HT leads
• Coil packs
• Mass airflow meter

If your juddering issue seems to get worse as you speed up, it might be caused by imbalanced wheels, many tyre shops offer a free balance check, but even so it can be done fairly cheaply.

One other cause that may feel similar to an imbalanced wheel is if your tyre has a bulge, check all around the tyre's tread and sidewall for a protruding lump. If found, organise a replacement to be fitted as soon as possible. 

Spread out the cost of new tyres with Bumpers zero-percent interest tyre financing. 

How to Fix Juddering Whilst Braking

If the juddering only happens when braking, it is likely that something in the braking or suspension is awry, the first thing to check would be your track rod ends, many garages offer a free suspension check-up, where they can feel for play. 

If nothing is reported with the suspension, have a mechanic take the car for a test drive, warped brake discs are usually resolved simply by fitting a new set of discs and pads.

Fixing Juddering Whilst Idling on Your Car

Worn engine mounts can be diagnosed relatively easily, simply have someone open the bonnet and watch the engine as you give it a few revs, if it moves significantly - more than a few centimetres back and forth - then there’s a good chance you need new engine mounts. 

Dual mass flywheels are a little harder to diagnose at home, but any mechanic should be able to tell you if that is the problem after a short test drive. Unfortunately, a new DMF is likely to cost upwards of £1,000, so be sure to check out Bumper’s zero-percent financing for DMFs.

When To Consult a Mechanic

If you notice any new noise or vibration from your car, and you’re unsure what it is, it’s probably worth getting a mechanic to take a look. This is both from a safety point of view and to prevent the problem from getting worse and causing other faults to occur. 

Some of the issues mentioned above can be felt or heard inside the car before they are a safety issue, but problems involving brakes, suspension or the engine itself should be addressed immediately by a qualified professional.

Fix Any Issues With Your Car Through Bumper

Bumper offers zero-per cent interest financing through one of the thousands of approved partners across the country, this gives you the opportunity to get your car sorted now, but pay for it over a period of time, at no extra cost.