Repair Operations Possible With The Engine In The Vehicle; Top Dead Center (Tdc) For Number One Piston-Locating - Jeep cherokee 1989 Owner's Manual

2A-2
Torque specifications
Camshaft sprocket bolt
Crankshaft pulley-to-vibration damper bolts
Cylinder head bolts
1984 through 1987
Step 1
Step 2
Step 3
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bolt 8 only
All other bolts
Step 1
Step 2
Step 3
Bolt 8 only
All other bolts
Driveplate bolts
Step 1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
S t e p 2
Exhaust manifold nuts
Flywheel bolts
Step 1
S t e p 2
Intake manifold-to-cylinder head bolts
Oil pan mounting bolts
1 1 4 x 2 0
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil pump bolts
Short
Long
Rocker arm capscrews
Rocker arm cover-to-cylinder head bolts
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
With pre-cured permanent gasket
Tensioner bracket-to-block bolts
Timing chain cover-to-block
Bolts
Nuts
Vibration damper bolt (lubricated) . . . . . . . . . . . . . . . . . . . . .
1 General information
This Part of Chapter 2 is devoted to in-vehicle repair procedures for
the 2.5 liter four-cylinder engine. Information concerning engine
removal and installation, as well as engine block and cylinder head
overhaul, is in Part D of this Chapter.
The following repair procedures are based on the assumption that
the engine is installed in the vehicle. If the engine has been removed
from the vehicle and mounted on a stand, many of the steps included
in this Part of Chapter 2 will not apply.
The Specifications included in this Part of Chapter 2 apply only to
the engine and procedures in this Part. The Specifications necessary
for rebuilding the block and cylinder head are found in Part D.
2

Repair operations possible with the engine in the vehicle

Many major repair operations can be accomplished without removing
the engine from the vehicle.
Clean the engine compartment and the exterior of the engine with
some type of pressure washer before any work is done. A clean engine
will make the job easier and will help keep dirt out of the internal areas
of the engine.
Depending on the components involved, remove the engine cover
and, if necessary, the hood to improve access to the engine as repairs
are performed (refer to Chapter 11 if necessary).
If vacuum, exhaust, oil or coolant leaks develop, indicating a need
for gasket or seal replacement, the repairs can generally be made with
the engine in the vehicle. The intake and exhaust manifold gaskets,
oil pan gasket and cylinder head gasket are all accessible with the
engine in place.
Exterior engine components such as the intake and exhaust
manifolds, the oil pan (and the oil pump), the water pump, the starter
The Motor Manual Guy
2 A
Chapter Part Four-cylinder engine
Ft-lbs (unless otherwise indicated)
80
20
4 0
Turn an additional 6 0 °
23
50
Turn an additional 6 0 °
23
55 in-lbs
4 4 in-lbs
14
motor, the alternator, the distributor and the carburetor or fuel injection
components can be removed for repair with the engine in place.
valve component servicing can also be accomplished with the engine
in the vehicle.
or replacement of piston rings, pistons, connecting rods and rod bear-
ings is possible with the engine in the vehicle. However, this practice
is not recommended because of the cleaning and preparation work that
must be done to the components involved.
3 Top Dead Center (TDC) for number one piston
Refer to illustrations 3.6 and 3.8
Note: The following procedure is based on the assumption that the
distributor is correctly installed. If you are trying to locate TDC to in-
stall the distributor correctly, piston position must be determined by
feeling for compression at the number one spark plug hole, then aligning
the ignition timing marks as described in step 8.
1
each piston reaches as it travels up-and-down when the crankshaft
turns. Each piston reaches TDC on the compression stroke and again
on the exhaust stroke, but TDC generally refers to piston position on
the compression stroke.
2
cedures such as rocker arm removal, camshaft and timing chain1
sprocket removal and distributor removal.
3
in Neutral and apply the parking brake or block the rear wheels. Also,
remove the spark plugs (see Chapter 1
using one of the following methods:
Since the cvlinder head can be removed without oullina the enaine.
In extreme cases caused by a lack of necessary equipment, repair
Top Dead Center (TDC) is the highest point in the cylinder that
Positioning the pistonk) at TDC is an essential part of many pro-
Before beginning this procedure, be sure to place the transmission
a) On ignition systems with the ignition coil mounted separately
from the distributor, detach the coil wire from the center terminal
.
locating
and disable the ignition system