3237837 - 1080A20 smokiness at exhaust - check with opacimeter

Start the engine and warm up until the radiator cooling fan comes on for the second time.

Leave as little time as possible between the engine preheating stage and the moment the test begins and avoid a prolonged idling period.

Check that sensor diameter is at least 0.22 times exhaust pipe diameter.

Ensure that the exhaust gas uptake fitting joints are effective enough to prevent leaks.

Position the fume measurement device sensor in the exhaust tail-pipe. Take care that the end is placed in a pipe section where the gas flow is uniformly distributed.If necessary, to meet the above requirements, fit an exhaust pipe extension so that the exhaust pipe coupling is sealed and the sensor end is located in a straight section at least six times as long as the exhaust tail-pipe diameter toward the engine and at least three times the tail-pipe diameter downstream.

Check that the sensor uptake pipe from the exhaust tail-pipe to the fume measurement device is on an upward slope and does not include acute angled kinks.

Ensure that the counter-pressure to the sensor is as specified and does not exceed 7.5 mbars during the test.

With the engine on and idling, place the gearbox in neutral and release the clutch pedal.Position the fume measurement meter to allow the uptake of exhaust gas.Record the reading shown on the fume meter gauge.As the engine is idling, rapidly and gently pump the accelerator pedal until the engine is turning at maximum speed and the governor cuts in.Record and note the maximum fume value marked on the fume meter during the acceleration without considering values during the release stage.As soon as the maximum rotation speed is reached, release the accelerator pedal until the engine is idling again.Check that the fume meter point returns to the position corresponding to the idling reading.Repeat the above operations at least six times until the fume readings entered have stabilised.

The readings are considered to have stabilised when four consecutive readings are within a 0.25 m -1 range and are not in decreasing order.

The fume values to be considered are the arithmetic mean of the four stabilised values. Check that the calculated fume value complies with the specified value printed on the vehicle marking summary plate located in the engine bay and indicated in the table below.

	Measurement		Value
-	Exhaust fumes (m¯ 1)		1.15