Does your car experience unwelcome shudders or judders when you accelerate, pull away, or even idle at traffic lights?  While these tremors can be disconcerting, the good news is they’re often indicators of common issues with relatively simple solutions.  This guide delves into the most frequent causes of car juddering and provides tips on how to address them.

Under the Bonnet – Why Cars Jerk When Accelerating

If your car exhibits jerky movements when you press the accelerator, the culprit could be a lack of essential ingredients for the combustion process: fuel, air, or spark.  One of the most common reasons for this is worn-out spark plugs or faulty spark plug leads.  A malfunctioning spark plug disrupts the engine’s ability to ignite the fuel properly, leading to misfires and that telltale jerking sensation.  Additionally, a clogged catalytic converter can impede airflow within the exhaust system, causing a similar hesitation and jerk when accelerating.  You might also notice a pungent egg-like odour emanating from the exhaust.

DIY or Seek Help? Fixing Acceleration Judders

If the problem stems from something straightforward like faulty spark plugs, some car owners with a bit of mechanical know-how might feel comfortable replacing them themselves.  For minor blockages, a good quality catalytic converter cleaner might do the trick.  However, if you’re unfamiliar with the inner workings of your car or suspect a more significant blockage, seeking professional help is the wisest course of action.  Consulting a reliable mechanic ensures the issue is diagnosed and addressed accurately.

Clutch Control – Why Cars Shudder When Pulling Away

If the juddering occurs specifically when pulling away in first gear, the clutch might be the source of the problem.  This could be due to worn-out friction material on the clutch plate, a faulty pressure plate, or even oil contamination on the clutch.

Clutch Repairs – Best Left to the Professionals

Diagnosing a clutch issue requires determining whether it’s a mechanical problem or simply clutch facing contamination.  This is a task best entrusted to a qualified mechanic.  Replacing a clutch is a specialised repair, so take your car to a reputable garage to ensure the work is carried out correctly.

The Low-Rev Problem – Understanding Shudders at Low Speeds

Car juddering at low revs can be particularly frustrating.  This often manifests at low speeds but disappears as you shift into higher gears.  Moisture accumulating in the distributor cap can cause these juddering episodes, especially when accelerating at low speeds or revs.  If your car is parked overnight in cold weather, condensation can form inside the distributor cap, hindering proper spark delivery and causing engine misfires.  Another possibility is worn engine mounts, the components responsible for keeping the engine securely fastened to the chassis.  Loose, worn, or broken mounts can lead to vibrations at low revs.

Combating Low-Rev Judders – Prevention and Solutions

Parking your car in a garage or covered space helps prevent moisture build-up in the distributor cap.  If on-street parking is unavoidable, a thermal cover can help minimise condensation risk.  Replacing worn engine mounts is a job best left to a qualified mechanic, as the engine needs to be securely supported during the repair process.

Engine Jitters at Idle – Why Cars Shudder While Stationary

Does your car’s engine shudder and seem like it might stall when idling at traffic lights?  This could be caused by faulty spark plugs or a build-up of grime and dirt within the system.  Clogged filters or a malfunctioning fuel injection system can also starve the engine of the fuel or oxygen it needs, resulting in juddering and shaking.  Over time, as a car accumulates mileage, the engine valves can become clogged with sludge.  If the engine doesn’t receive a consistent and clean fuel supply, it can begin to judder or shudder while idling.  Alternatively, if the juddering only occurs at idle, it could be a small leak on the vacuum side of the engine or a worn-out electrical component like the crankshaft sensor.

Keeping Idling Smooth – Solutions and Preventative Measures

Unless you’re a seasoned mechanic, tackling component replacements yourself is best avoided.  A trusted garage can examine your car and conduct diagnostic tests to pinpoint the root cause of the idling judder.  As a preventative measure, regularly inspect your engine for signs of dirt and dust build-up, and ensure you get your car serviced annually or every 10,000-12,000 miles.  Having the right breakdown cover in place provides peace of mind in case of unexpected issues on the road.

High-Speed Shudders – When Cars Tremble at Cruising Speeds

If you experience shaking and juddering while travelling at higher speeds on motorways or A roads, there could be several culprits.  Dirty fuel injectors, a damaged fuel pump or a blocked catalytic converter can all contribute to this issue.  A faulty mass airflow sensor, worn spark plugs, or even accumulated moisture can also be at play.  These problems disrupt the engine’s ability to function smoothly at higher speeds, resulting in the juddering sensation.

Dealing With High-Speed Judders – Diagnosis and Repair

If the cause is simply minor dirt or moisture build-up, cleaning the affected components and applying appropriate lubricants might be sufficient.  However, for more serious issues, consulting a mechanic is essential.  Regular maintenance plays a crucial role in preventing these problems.  Scheduled servicing allows qualified professionals to identify and address potential issues before they escalate into high-speed judders.  Over time, certain car parts inevitably require replacement, and a trusted garage can ensure these replacements are carried out correctly, keeping your car running smoothly at all speeds.

The Jitters When Braking – Understanding Brake Disc Issues

Juddering during braking often stems from uneven brake disc thickness or deformation.  For effective braking, the discs require a uniform thickness to ensure smooth contact with the brake pads.  Unevenness creates friction imbalances, causing the juddering sensation in the steering wheel.

Fixing Brake Judder – Solutions and Safety Precautions

If caught early, cleaning both the brake discs and the surrounding areas might temporarily alleviate the juddering.  However, this is a temporary fix, and replacements will likely be necessary in the near future.  Driving with damaged brake discs is highly dangerous and can significantly compromise your braking ability.  If you suspect warped brake discs, get them replaced as soon as possible.

Diesel Dilemmas – Why Diesel Cars Shudder

Diesel engines are prone to a specific set of potential problems, and juddering while driving is a common one.  The most frequent culprit is clogged fuel injectors.  These injectors deliver fuel into the engine cylinders, and blockages prevent a proper fuel spray, leading to juddering and hesitation.

Fixing Diesel Shudders – A Simple Solution

Fortunately, cleaning clogged fuel injectors is a relatively straightforward process.  A mechanic can remove the injectors, clean them thoroughly, reinstall them, and then restart the vehicle.  This relatively simple fix can restore smooth operation to your diesel car.

Tyres – The Cause and the Solution

Throughout your car’s ownership, you’ll likely encounter various tyre-related issues.  One consequence of these problems can be juddering and stuttering while driving.  Uneven tyre wear, damaged tyres, incorrect tyre pressure, or unbalanced wheels can all contribute to this juddering sensation.  Over time, loose lug nuts can also develop, adding to the problem.

Keeping Tyres in Top Shape – Prevention and Solutions

Maintaining proper tyre pressure and wheel alignment is crucial for preventing juddering caused by tyre and wheel issues.  Regularly checking your tyre pressure and scheduling tyre rotations and balancing helps ensure smooth operation.  If you experience juddering, getting a wheel alignment or replacing worn tyres can often resolve the problem.  For all your tyre needs, RAC Tyres offers a convenient and reliable solution.


By understanding the common causes of car juddering and taking appropriate action, you can ensure a smoother and safer driving experience.  Regular maintenance, including servicing and tyre checks, plays a vital role in preventing these issues from arising.  However, if you do encounter juddering, don’t hesitate to consult a qualified mechanic for a proper diagnosis and repair.  Remember, a car judder is often a warning sign of a potential problem, and addressing it promptly can save you money and hassle in the long run.  Drive safe!