Volvo 940 - Manual (Page 186)

1993 Volvo 940
charcoal canister with built-in vacuum valve under the left-front wheel housing. The components are
interconnected by hoses which channel fuel vapor from the gas tank to the charcoal filter, where it is
stored until the engine is started and then drawn into the engine's fuel-induction system.
Crankcase ventilation
The engine is equipped with positive crankcase ventilation which prevents crankcase gases from being
released into the atmosphere. Instead, the crankcase gases are admitted to the intake manifold and
cylinders.
PCV system
The PCV nipple in the intake manifold should be removed and inspected every 60,000 miles (96,000
km).
Check/replace hoses at the same time.
Exhaust Gas Recirculation (EGR)
This system operates by returning some of the exhaust gases to the engine to be recombusted: since this
lowers the combustion temperature the amount of nitrogen oxides released into the atmosphere is
reduced.
The EGR valve should be cleaned at 100,000 miles (160,000 km) and thereafter cleaned every 20,000
miles (32,000 km).
* B 230 FD only: clean at 100,000 miles (160,000 km).
pg. 8:11 Servicing
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