Exhaust Diagnosis - Dodge D150 1990 Service Manual

EXHAUST SYSTEM AND INTAKE MANIFOLD 1 1 - 3
E X H A U S T DIAGNOSIS
CONDITION P O S S I B L E C A U S E
CORRECTION
EXCESSIVE EXHAUST
NOISE
(a) Leaks at pipe joints.
(b) Burned or blown out muffler.
(c) Burned or rusted out exhaust pipe.
(d) Exhaust pipe leaking at manifold flange.
(e) Exhaust manifold cracked or broken.
(f) Leak between manifold and cylinder head.
(g) Restriction in muffler or tail pipe.
(a) Tighten clamps at leaking joints.
(b) Replace muffler assembly.
(c) Replace exhaust pipe.
(d) On all engines, tighten bail joint connection
attaching bolt nuts to 33 N*m (24 ft. lbs.)
alternate tightening.
(e) Replace manifold.
(f) Tighten manifold to cylinder head stud nuts
or bolts to specifications.
(g) Remove restriction, if possible, or replace
as necessary.
LEAKING EXHAUST GASES (a) Leaks at pipe joints.
(b) Damaged or improperly installed gaskets.
(a) Tighten U-bolts at leaking joints to
17 N-m (150 in. lbs.)
(b) Replace gaskets as necessary.
ENGINE HARD TO WARM
UP OR WILL NOT RETURN
TO NORMAL IDLE
(a) Heat control valve frozen in the open
position.
(b) Blocked crossover passage in intake
manifold.
(a) Free up manifold heat control valve using a
suitable solvent.
(b) Remove restriction or replace intake manifold.
HEAT CONTROL VALVE
NOISY
(a) Thermostat broken.
(b) Broken, weak or missing anti-rattle spring.
(a) Replace thermostat.
(b) Replace spring.
J9011-33
S E R V I C E P R O C E D U R E S
INDEX
Page Page
Exhaust Manifold
. . . . . . . . . . . . . . . . . . . . . . . . . 12
Manifold Heat Control Valve
. 13
Exhaust Pipe, Mufflers, Converters and Tailpipe . . . 3 Torque Specifications 14
Intake Manifold 10
EXHAUST PIPE, MUFFLERS, CONVERTERS AND
TAILPIPE
REMOVAL (GENERAL)
(1) Raise vehicle on hoist a n d apply p e n e t r a t i n g o i l
to clamp bolts and nuts of component being removed.
(2) Remove clamps and supports f r o m exhaust sys-
t e m to p e r m i t a l i g n m e n t of p a r t s d u r i n g assembly.
(3) Clean ends of pipes and/or muffler to assure
m a t i n g of a l l parts. Discard b r o k e n or w o r n insula-
tors, rusted clamps, supports a n d a t t a c h i n g parts.
W h e n replacement is r e q u i r e d on any component o f
the exhaust system, i t is most i m p o r t a n t t h a t o r i g i -
n a l equipment parts (or t h e i r equivalent) be used to
assure proper a l i g n m e n t w i t h other parts i n the sys-
t e m and provide acceptable exhaust noise levels.
INSTALLATION (GENERAL)
(1) Assemble pipes, muffler, supports and clamps
loosely to p e r m i t proper alignment of a l l parts.
(2) B e g i n n i n g a t f r o n t of system, a l i g n and clamp
each component t o m a i n t a i n position a n d proper
clearance w i t h underbody parts.
(3) O n models u s i n g ball-type connections, alter-
n a t e l y t i g h t e n bolts t o assure flanges are even and
p a r a l l e l .
(4) T i g h t e n a l l clamps and supports to the proper
torques (Figs. 1 t h r u 6).