Why Does My Car Shake When I Accelerate?

Vibration at speed versus vibration under load

The first question to ask is when exactly the shaking happens. Vibration that starts at a specific speed — say 50 to 60 mph — and then smooths out above that speed is almost always a wheel balance or tyre issue. Vibration that appears specifically when you accelerate hard, or when the engine is under load, points toward drivetrain components.

Vibration only at low speed pulling away, particularly on front-wheel-drive cars, often points at worn CV joints or driveshafts. These components handle the combination of power delivery and steering angle — when they wear, they produce a shudder particularly noticeable at low speed on full or partial steering lock.

Wheel balance and tyres

An unbalanced wheel causes a vibration that is speed-dependent. As tyre wear progresses, small imbalances develop. Each wheel should be balanced when new tyres are fitted, and occasionally rechecked if you notice vibration appearing over time. Wheel balancing at The Car Guys is quick and inexpensive compared to the cost of tyre wear it prevents.

A damaged or buckled wheel, or a tyre with a broken internal belt, can produce vibration that appears suddenly — often after hitting a significant pothole. Inspect the tyre sidewalls for bulges and the rim for visible damage if vibration appears suddenly after a road incident.

CV joints and driveshafts

Constant velocity (CV) joints connect the driveshafts to the wheels and allow them to transmit power through the steering angles. They are protected by rubber boots filled with grease. When a CV boot splits and the grease is lost, the joint wears rapidly and develops a clicking or shuddering noise under acceleration, particularly on corners.

A clicking noise specifically when turning at slow speed is a classic sign of a worn outer CV joint. Shuddering during straight-line acceleration at low speed more often indicates an inner joint or driveshaft vibration. Both should be looked at before they deteriorate further — a full driveshaft replacement is considerably more expensive than replacing the joint and boot alone if caught early.

Engine and gearbox-related causes

Engine misfires can cause vibration that is felt through the whole car, particularly under acceleration. A misfire produces an uneven power stroke, and at moderate speeds this creates a noticeable shudder. Fault codes stored in the engine management system will often point to which cylinder is misfiring.

Worn engine or gearbox mounts allow the powertrain to move excessively under load. Normally the mounts absorb vibration; worn mounts transmit it directly to the body. Vibration under acceleration that is accompanied by a thud or clunk when selecting a gear is a common symptom of failed mounts.

Getting it diagnosed

Because vibration can have several causes, a road test followed by an inspection is the most reliable way to identify it. We test drive to reproduce the symptom, then inspect wheels, tyres, CV joints, mounts, and run a diagnostic scan to check for misfires. Contact The Car Guys on 01527 336608 or book online.