Exhaust Emission Control

EMISSION CONTROL - K SERIES KV6

17-3-4

DESCRIPTION AND OPERATION

Description

General
The vehicle is fitted with the following control systems to reduce emissions released into the atmosphere:

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Crankcase emission control.

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Exhaust emission control.

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Evaporative emissions (EVAP) control.

CAUTION: In many countries it is against the law for a vehicle owner or an unauthorised dealer to modify or 
tamper with emission control equipment. In some cases, the vehicle owner and/or the dealer may even be 
liable for prosecution.

The emission control systems fitted to the vehicle are designed to keep the emissions within the legal limits, at the 
time of manufacture, provided that the engine and the fuel system components are correctly maintained and in good 
mechanical condition.

Crankcase Emission Control System
The crankcase is vented via the oil drain passages in the cylinder blocks and cylinder heads and two ports in each 
camshaft cover. Plastic pipes connect the larger ports in the camshaft covers to the intake duct, on the upstream side 
of the throttle disc. The smaller ports in the camshaft covers are connected to the inlet manifold, downstream of the 
throttle body, also by plastic pipes. Each of the smaller ports incorporate a restrictor and a gauze oil separator to 
prevent oil being drawn out of the camshaft covers with the blow-by gases. Quick release locking collars and 'O' rings 
are used for all of the pipe connections with the camshaft covers, throttle body and air intake duct.

When the engine is running with the throttle disc closed, the depression downstream of the throttle disc draws 
crankcase gases into the inlet manifold through the smaller ports in the camshaft covers. Clean air, from the upstream 
side of the throttle disc, is drawn into the crankcase through the larger ports in the camshaft covers to limit the 
depression produced in the crankcase.

When the engine is running with the throttle disc wide open, the upstream and downstream sides of the throttle disc, 
and thus the two ports in each camshaft cover, are subjected to similar, relatively weak, depression levels. Crankcase 
gases are then drawn out of both ports in each camshaft cover, with the majority being drawn out of the unrestricted 
larger ports and into the throttle body.

At interim throttle disc positions the flow of the crankcase gases varies, between those produced at the closed and 
wide open throttle disc positions, depending on the depression levels produced upstream and downstream of the 
throttle disc.

Exhaust Emission Control
The engine management systems provide accurately metered quantities of fuel to the combustion chambers to 
ensure the most efficient use of fuel and to minimise the exhaust emissions. In some markets, to reduce the carbon 
monoxide and hydrocarbons content of the exhaust gases, catalytic converters are installed in the exhaust system. 
A catalytic converter is integrated into each downpipe close to the exhaust manifolds.