leave you fuming!
As part of the MOT test your vehicle will be checked for smoke emissions. This helps the environment by minimising pollution and testing the fuel efficiency of vehicles. It also helps you by checking that the engine is working correctly and reducing waste. So...
How diesel emissions are tested
The test has been developed so that it should not damage your engine. The tester will
check the maintenance history of your vehicle by asking you some questions. The
tester must refuse to test your vehicle if he thinks that the smoke test may damage
your engine.
Please tell the tester if you think the smoke test may damage your engine
To reduce the possibility of damage and increase the chances of passing you should:
• keep your vehicle maintained at all times
• have the camshaft drive belt replaced at the recommended intervals
• go for the test with a fully warmed up engine - it will produce less smoke and is safer
to test
• do not tamper with the governor settings. They are set to help ensure the engine runs efficiently.
The test station is not permitted to ask you to sign a disclaimer. However, you may sign this card to say that you have read the contents.
The test
After checking the oil temperature to ensure the engine is warm the tester will accelerate the engine from idle until the governor cuts in a maximum of 6 times. your
engine will not be held at full speed for any length of time. If your engine has been
maintained, the test should not cause damage to your engine.
MOTCompl/1126/Jan 05
