Exhaust Manifold Replacement - Jeep J-10 Series 1982 Technical & Service Manual

1K-4 EXHAUST SYSTEMS
SEAL
/^ REAR EXHAUST
J PIPE (TRUCK ONLY)
MUFFLER
81047B
Fig. 1K-4 Eight-Cylinder Engine Exhaust System—Cherokee-Wagoneer-Truck
EXHAUST MANIFOLD REPLACEMENT
Four-Cylinder Engine
The exhaust manifold is located on the left hand side
of the engine (fig. 1K-5). Refer to Chapter IB—Engines
for replacement procedure.
Six-Cylinder Engine
The intake and exhaust manifolds are attached with
common bolts and nuts to the cylinder head on the left
side of the engine. A gasket is used between the intake
manifold and the cylinder head. No gasket is used be
tween the exhaust manifold and cylinder head or be
tween exhaust manifold and exhaust pipe (fig. 1K-6).
Refer to Chapter IB—Engines for replacement
procedure.
Eight-Cylinder Engine
Refer to Chapter IB—Engines for replacement
procedure.
EXHAUST MANIFOLD HEAT VALVE
Four- and six-cylinder engines are not equipped with
heat valves.
Eight-Cylinder Engine
A thermostatically controlled heat valve mounted be
tween the right exhaust manifold and exhaust pipe di
rects exhaust heat to the intake manifold for rapid fuel
vaporization during engine warmup. When the counter
weight is in the horizontal position, the valve is in the
heat On position, directing exhaust heat through the
intake manifold crossover passage (fig. 1K-7). The ex
haust heat crosses through the intake manifold and dis
charges into the left exhaust manifold until the engine
attains normal operating temperature. At this time, the
heated bimetallic spring loses its tension, the counter
weight moves downward and the valve moves to the
heat Off position. This allows the exhaust heat to dis
charge completely through the right exhaust pipe.
Examine the manifold heat valve for freedom of
movement and lubricate every 30,000 miles (48 000 km)
with Jeep Heat Valve Lubricant, or equivalent.