Dodge ram truck 3500 1996 Service Manual page 992

9 - 2 ENGINE
GENERAL INFORMATION (Continued)
GASKET APPLICATION
Assembling parts using a form-in-place gasket
requires care.
Mopar® Silicone Rubber Adhesive Sealant should
be applied in a continuous bead approximately 3 mm
(0.12 inch) in diameter. All mounting holes must be
circled. For corner sealing, a 3 or 6 mm (1/8 or 1/4
inch) drop is placed in the center of the gasket con­
tact area. Uncured sealant may be removed with a
shop towel. Components should be torqued in place
while the sealant is still wet to the touch (within ten
minutes). The use of a locating dowel is recom­
mended during assembly to prevent smearing the
material off location.
Mopar® Gasket Maker should be applied sparingly
to one gasket surface. The sealant diameter should
be 1.00 mm (0.04 inch) or less. Be certain the mate­
rial surrounds each mounting hole. Excess material
can be easily wiped off. Components should be
torqued in place within 15 minutes. The use of a
locating dowel is recommended during assembly to
prevent smearing the material off location.
ENGINE PERFORMANCE—GASOLINE ENGINES
To provide best vehicle performance and lowest
vehicle emissions, i t is most important that the
tune-up be done accurately.. Use the specifications
listed on the Vehicle Emissions Control Information
label found on the engine compartment hood.
(1) Test cranking amperage draw. Refer to Group
8B, Battery/Starter/Generator Service, for the proper
procedures.
(2) Tighten the intake manifold bolts. Refer to
Group 11, Exhaust System and Intake Manifold, for
the proper procedure and torque specifications.
CAUTION: DO NOT overspeed the engine.
(3) Perform cylinder compression test:
(a) Check engine oil level and add oil, i f neces­
sary.
(b) Drive the vehicle until engine reaches nor­
mal operating temperature.
(c) Select a route free from traffic and other
forms of congestion, observe all traffic laws, and
briskly accelerate through the gears several times.
The higher engine speed may help clean out valve
seat deposits, which can prevent accurate compres­
sion readings.
(d) Remove all spark plugs from engine. As
spark plugs are being removed, check electrodes for
abnormal firing indicators—fouled, hot, oily, etc.
Record cylinder number of each spark plug for
future reference.
(e) Disconnect coil wire from distributor or from
both coil packs (V-10) and secure to good ground to
prevent a spark from starting a fire.
(f) Be sure throttle blades are fully open during
the compression check.
(g) Insert compression gauge adaptor into the
No.l spark plug hole. Crank engine until maxi­
mum pressure is reached on gauge. Record this
pressure as N o . l cylinder pressure.
(h) Repeat Step 3g for all remaining cylinders.
(i) Compression should not be less than 689 kPa
(100 psi) and not vary more than 172 kPa (25 psi)
from cylinder to cylinder.
(j) I f cylinders) have abnormally low compres­
sion pressures, repeat steps 3a through 3h.
(k) I f the same cylinder(s) repeat an abnormally
low reading, it could indicate the existence of a
problem in the cylinder.
NOTE: The recommended compression pressures
are to be used only a s a guide to diagnosing engine
problems. An engine should NOT be disassembled
to determine the cause of low compression unless
some malfunction is present.
(4) Clean or replace spark plugs as necessary.
Adjust gap. Refer to Group 8D, Ignition System, for
gap adjustment and torque specifications.
(5) Test resistance of spark plug cables. Refer to
Group 8D, Ignition System, for procedure.
(6) Inspect the primary wire. Test coil output volt­
age, primary and secondary resistance. Replace parts
as necessary. Refer to Group 8D, Ignition System,
and make necessary adjustment.
(7) Set ignition timing to specifications. Refer to
Specification Label on engine compartment hood.
(This step does not apply to 8.0L engines.)
(8) Perform a combustion analysis.
(9) Test fuel pump for pressure and vacuum. Refer
to Group 14, Fuel System, for the proper specifica­
tions.
(10) Inspect air filter element. Refer to Group 0,
Lubrication and Maintenance, for the proper proce­
dure.
(11) Inspect crankcase ventilation system. Refer to
Group 0, Lubrication and Maintenance, for the
proper procedure.
(12) For emissions controls, refer to Group 25,
Emissions Controls System for service procedures.
(13) Inspect and adjust accessory belt drives. Refer
to Group 7, Cooling System, for the proper adjust­
ments.
(14) Road-test vehicle as a final test.
MEASURING WITH PLASTIGAGE
C R A N K S H A F T MAIN BEARING CLEARANCE
Engine crankshaft bearing clearances can be deter­
mined by use of Plastigage, or equivalent. The follow-