Air Cleaner; Checking And Adjusting Idle Speed; Lambda-Sond (Oxygen Sensor) System; Engine Crankcase Ventilation System - Volvo 240 User Manual

1987 Volvo 240

Air cleaner

Replace the air cleaner cartridge every 30,000 miles (48,000 km). The cartridge should be replaced more often when driving under dirty and/or
dusty conditions. The filter cannot be cleaned and should always be replaced with a new one.

Checking and adjusting idle speed

Your Volvo is equipped with an electronically controlled idle speed system that requires no period checking or adjustment.
Lambda-sond® (oxygen sensor) system
This is an emission control system designed to reduce emissions and improve fuel economy. An oxygen sensor monitors the composition of
the exhaust gases leaving the engine. The exhaust gas analysis is fed into an electronic unit which continuously influences the amount of fuel
injected. This adjusts the air-fuel ratio to provide optimum conditions for combustion and efficient reduction of the three major pollutants
(hydrocarbons, carbon monoxide and nitrogen oxides) through a 3-way catalytic converter.
pg. 65 Servicing
Oxygen Sensor
On the B230F engines, the oxygen sensor (Lambda-sond®) is electrically heated. The use of a PTC (Positive Temperature Coefficient)
element to heat the Lambda-sond ensures a shorter warm up time and continuous operation at its working temperature.
This type of Lambda-sond® does not require periodic replacement.
Catalytic Converter
This is a supplementary device in the exhaust system, designed to reduce exhaust emissions.
This device is mainly a container with a ceramic material insert, designed to let the exhaust gases pass through channels in the insert. The
channel walls are covered by a thin layer of platinum and rhodium. These metals act as catalysts, permitting a chemical action to occur without
actually taking part in it.
The carbon monoxide content will increase if the Catalytic Converter is damaged.
CAUTION:
Vehicles with Catalytic Converter must use unleaded fuel only. Otherwise the Catalytic Converter will become damaged and ineffective.
Torque catalytic converter mounting bolts
The Catalytic Converter mounting bolts should be re-torqued at the 600-1,200 mile (1000-2000) km inspection.
pg. 66 Servicing

Engine Crankcase Ventilation System

Crankcase ventilation
The engine is provided with positive crankcase ventilation (PCV) which prevents crankcase gases from being released into the atmosphere.
Instead, the crankcase gases are admitted to the intake manifold and cylinders.
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