Whilst you are waiting to be called forward for the MOT test, use this time to check the following:
familiarise yourself with the vehicle controls, all light switches, boot, bonnet, fuel cap operation and so on
ensure any headlamp levelling device is set in the correct position for a vehicle without a load (usually a small wheel control on the dash which is numbered. In most cases the correct position will be at 0)
please have the vehicle registration certificate, appointment card and previous MOT certificate (if applicable) readily available for examination
The smoke emitted from compression ignition (diesel) engined vehicles is assessed for its density. It is carried out by the use of an approved and calibrated smoke meter.
The engine will be accelerated up to governed speed and the density of the smoke measured.
After the third acceleration the average reading is recorded. If the reading is below 2.5m-1 for non-turbocharged engines or 3.0m-1 for turbocharged engines the vehicle will pass.
However if the average is higher, a further acceleration is carried out and the average of the last three readings are used, this will continue until a maximum of six accelerations have been carried out.
If the average of the fourth, fifth and sixth acceleration is higher than the appropriate level the vehicle will not pass the test.
In addition to the smoke meter readings, any of the following will result in the vehicle being refused a certificate:
emissions cannot be measured because a tail pipe is damaged or an accessory is fitted which prevents the insertion of the smoke meter probe
insufficient oil in the engine or low oil pressure which could cause engine damage if engine is accelerated
obvious signs of an engine defect such as an unusual noise or emission of smoke
obvious signs that the governors have been tampered with or not operating
This test applies to all cars, taxis, minibuses and ambulances with up to 12 passenger seats, and other vehicles up to and including 3,500 kg design gross weight (DGW), which are spark ignition (petrol) engined with four or more wheels.
Any of the following points will result in the vehicle being refused a certificate:
the engine emits dense blue or clearly visible black smoke for a continuous period of five seconds at idle
the engine emits dense blue or clearly visible black smoke during acceleration, which would obscure the view of other road users
the emissions cannot be measured because the tailpipe is damaged or an accessory is fitted which prevents insertion of the analyser probe
the exhaust gas contains one or more gases in excess of the required limits for the associated test
Vehicles first used prior to 1 August 1975 are exempt from a metered emission test.
Vehicles first used on or after 1 August 1975 and before 1 August 1986:
hydrocarbons (HC) 1,200ppm (parts per million)
hydrocarbons (HC) 1,200ppm
While specific limits are too numerous to list the following is for guidance only:
carbon monoxide (CO) 0.5 per cent at idle
carbon monoxide (CO) 0.3 per cent at fast idle
lambda: 0.97 - 1.03 Lambda (value of 1 for the optimum air/fuel ratio setting)
Vehicles must be presented for test with the engine at normal working temperature. Therefore engine should be kept running on arrival at the test centre.
Under bonnet inspection
An under bonnet inspection is carried out at this stage (please be ready to release the bonnet catch when requested).
Also checked at this stage:
power assisted steering
engine transmission mounts
mechanical brake components
hydraulic, air and vacuum brake systems
brake and steering fluids
general condition of the vehicle
vehicle structural integrity and construction
European Directive 2007/38/EC requires trucks over 3.5 tonnes and first registered on or after 1 January 2000 to be fitted with a wide angle mirror and a close proximity mirror - both mirrors are to be fitted on the nearside of the vehicle.
These additional mirrors are required to help drivers detect other road users in the areas immediately around their vehicles, thus reducing the potential for collisions.