Perth Sheriff Court Dismisses Claim Against MOT Garage After Timing Belt Failure During Test

A Scottish court has dismissed a claim against an MOT testing station after a vehicle suffered catastrophic engine damage when its timing belt failed during an MOT emissions test.

The decision, handed down by Perth Sheriff Court, provides important reassurance for MOT testers and garages, confirming that they are not automatically liable when a hidden mechanical defect fails during the normal course of an MOT examination.

What happened?

The case centred on a Ford Galaxy that was presented to Halfords Autocentres in Perth for an MOT and interim service in February 2025.

During the emissions test, which requires the engine to be accelerated to prescribed speeds, the vehicle’s engine suddenly stopped.

Subsequent inspection at another garage revealed that the engine’s timing belt had snapped, causing extensive internal engine damage. Repairs totalled almost £7,800, although the owner sought the £5,000 limit available under Scotland’s Simple Procedure claims process.

The owner’s argument

The claimant argued that because the vehicle was in the custody of the MOT station, the garage should be responsible for the damage under Regulation 14 of the Motor Vehicles (Tests) Regulations 1981.

Essentially, the claim suggested that garages have strict liability for damage occurring while carrying out an MOT.

The garage’s defence

Halfords argued that:

• the MOT was carried out entirely in accordance with DVSA procedures;
• the timing belt is an internal component that cannot be inspected during an MOT;
• MOT testers are prohibited from dismantling engine covers to inspect components such as timing belts;
• the failure was due to the vehicle’s existing mechanical condition rather than anything the tester did.

The garage also stated that timing belt failures during emissions testing are exceptionally rare.

The Sheriff’s decision

Sheriff Mark Thorley dismissed the claim.

In his judgment, he concluded that:

• the MOT examiner followed normal testing procedures;
• there was no negligence by the tester;
• the timing belt was a concealed component that could not legally or practically be inspected during the MOT;
• Regulation 14 does not impose strict liability simply because damage occurs while the vehicle is at the testing station.

Instead, liability only arises where the tester actually causes damage through negligent actions or improper testing procedures.

Why this matters to MOT testers

The ruling reinforces an important principle that many MOT testers already understand.

An MOT is a visual and functional inspection, not a diagnostic examination.

Testers are required to follow the DVSA Inspection Manual and prescribed test procedures. They are not expected to identify hidden defects inside engines or dismantle components that fall outside the scope of the MOT.

Where a previously undetectable mechanical component fails during a correctly conducted test, this case confirms that liability will not automatically fall on the testing station.

A reminder for garages

Although this judgment is reassuring, garages should continue to:

• follow the DVSA MOT Inspection Manual precisely;
• ensure emissions tests are carried out correctly;
• accurately document any unusual incidents;
• explain clearly to customers that an MOT cannot detect every mechanical defect.

Good record keeping remains the strongest defence should a dispute arise.

Key takeaway

This case provides useful legal clarification for the MOT industry.

Where a hidden component such as a timing belt fails during the normal execution of an MOT test, and the tester has followed the correct procedures, the garage is unlikely to be held liable for the resulting damage.

For MOT testers, it reinforces that responsibility lies in carrying out the inspection correctly, not guaranteeing the condition of every internal engine component.