diesel emissions testing.
Discussion
Smoke tests are about to be introduced here as part of the MOT. I think they did try this a few years ago, but after a lot of engines blew up, and some legal action ensued, they stopped.
The new test involves holding the engine on the limiter for 5 secs, and monitoring smoke emissions.
I assume this is what is done on the mainland ??
Why have they chosen a test that is so abusive towards the engine, and such a scenario would NEVER be repeated during normal usage ?
What comeback to you have, if an engine fails whilst undergoing the test ??
Must check owners handbooks, but I'm sure I read somewhere, never to hold a diesel engine flat out, with no load on it ?
The new test involves holding the engine on the limiter for 5 secs, and monitoring smoke emissions.
I assume this is what is done on the mainland ??
Why have they chosen a test that is so abusive towards the engine, and such a scenario would NEVER be repeated during normal usage ?
What comeback to you have, if an engine fails whilst undergoing the test ??
Must check owners handbooks, but I'm sure I read somewhere, never to hold a diesel engine flat out, with no load on it ?
Info sheet supplied from DVTA.
The metered smoke test has been carried out in EU countries for many years. During this test a calibrated smoke meter is used to assess the density of smoke fromm compression ignition engined vehicles.
the engine will be accelerated up to teh governed speed and the smoke density measured. Engines that emit very little smoke will achieve a meter reading of 1.5m^-1 or less and will pass he test after the first acceleration, however if the test is not passed on the first acceleration, then a further two tests will be required.
The average of the three acceleration readings will be calculated and if the reaidng is at or below 2.5m^-1 for non-turbocharged engines, or 3.0m^-1 for turbocharged engines, the vehicle will pass this element of the test.
However, if the average is higher, a further acceleration will be carried out, and the averageof the last three readings will be calculated. This will continue up to a maximum of six accelerations. If teh average of the fourth, fifth, and sixth accelerations is higher than the appropriate level, the vehicle will not pass the test.
In addition, vehicles may be refused a certificate if the exhaust emits excessive smoke or vapour, to an extent likely to obscure vision.
A metered smoke tst will not be carried out if:
* The exhaust tailpipe is damaged or an accessory fitted which prevents insertion of the smoke meter probe.
* The exhaust system is extensively fractured or holed.
* There is obvious signs of an engine defect, such as unusual noise or emission of excessive smoke.
* There is insufficient or excessive amounts of oil in the engine, or low engine oil pressure, which could cause engine damage if teh engine is accelerated.
* There is obvious signs that the governors have been tampered with, or are not operating.
* The vehicle owner/presentor cannot confirm that the vehicle has been properly maintained, the camshaft drive belt has been replaced at the reccomended intervals and the engine is in a suitable condition for testing.
In the above circumstances where a metered smoke test is not carried out the vehicle will be refused a certificate.
NOTE:
It is important that vehicles are properly maintained prioer to testing ( including changing of the camshaft drive belts in accordance with the manufacturer's recommendation ) and presented for tst at normal working temperature. this may require the engine to be kept running prior to the start of the test.
Jeeeez, such amount of typing !!!!
The metered smoke test has been carried out in EU countries for many years. During this test a calibrated smoke meter is used to assess the density of smoke fromm compression ignition engined vehicles.
the engine will be accelerated up to teh governed speed and the smoke density measured. Engines that emit very little smoke will achieve a meter reading of 1.5m^-1 or less and will pass he test after the first acceleration, however if the test is not passed on the first acceleration, then a further two tests will be required.
The average of the three acceleration readings will be calculated and if the reaidng is at or below 2.5m^-1 for non-turbocharged engines, or 3.0m^-1 for turbocharged engines, the vehicle will pass this element of the test.
However, if the average is higher, a further acceleration will be carried out, and the averageof the last three readings will be calculated. This will continue up to a maximum of six accelerations. If teh average of the fourth, fifth, and sixth accelerations is higher than the appropriate level, the vehicle will not pass the test.
In addition, vehicles may be refused a certificate if the exhaust emits excessive smoke or vapour, to an extent likely to obscure vision.
A metered smoke tst will not be carried out if:
* The exhaust tailpipe is damaged or an accessory fitted which prevents insertion of the smoke meter probe.
* The exhaust system is extensively fractured or holed.
* There is obvious signs of an engine defect, such as unusual noise or emission of excessive smoke.
* There is insufficient or excessive amounts of oil in the engine, or low engine oil pressure, which could cause engine damage if teh engine is accelerated.
* There is obvious signs that the governors have been tampered with, or are not operating.
* The vehicle owner/presentor cannot confirm that the vehicle has been properly maintained, the camshaft drive belt has been replaced at the reccomended intervals and the engine is in a suitable condition for testing.
In the above circumstances where a metered smoke test is not carried out the vehicle will be refused a certificate.
NOTE:
It is important that vehicles are properly maintained prioer to testing ( including changing of the camshaft drive belts in accordance with the manufacturer's recommendation ) and presented for tst at normal working temperature. this may require the engine to be kept running prior to the start of the test.
Jeeeez, such amount of typing !!!!
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