timing belt VOLVO 240 1990 Owners Manual

Volvo 1990 240 Model
EMISSIONS
SYSTEM
MAINTENANCE
Engine oil and oil
filter R
R R R R R R R R R R R R
Cooling system
hoses and
connections I
Engine drive belts A I I
Torque manifold
nuts A
Valve clearance I I
Timing belt A R (3)
Vacuum fittings,
hoses and
connections I
Air cleaner filter R R
Idle RPM I
Fuel system cap,
tank, lines and
connections I
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Volvo 1990 240 Model
pg. 64 Service requirements
Engine Mechanical Components

Torque manifold nuts

The manifold nuts should be torqued at the 600-1,200 mile (1,000-2,000 \
km) inspection. A loose
manifold could alter air/fuel ratio and cause an increase in emission an\
d/or poor driveability.

Valves

The valve clearance should be checked every 30,000 miles (48,000 km). \

Vacuum fittings, hoses and connections

Unstable idle, misfiring or poor emission control is often caused by lea\
king vacuum hoses or
connections. Check hoses and connections on distributor vacuum unit, EGR\
valve (where applicable)
and connections on heater control servo systems and hydraulic brake serv\
o.

Exhaust Gas Recirculation (EGR)

This system operates by returning some of the exhaust gases to the engin\
e 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 the 60,000 mile inspection and therea\
fter cleaned every 25,000
miles (40,000 km).

Timing belt

The timing belt tensioner should be adjusted at the 600-1,200 mile (1,0\
00-2,000 km) inspection.
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