Chrysler Cirrus, Dodge Stratus, Plymouth Breeze Haynes. Manual — part 13
2C-2
Chapter 2 Part C General engine overhaul procedures
Four-cylinder engines (continued)
Valves and related components
Valve spring
Out of square limit. . . . . . . . . . . . . . . . . . . . . .. 1/16 inch
Free length (approximate)
2.0L . . . . . . . . . . . . . . . . . . . . . . . . . . 1.747 inches
2.4L . . . . . . . . . . . . . . . . . . . . .. . . . . . 1.905 inches
Installed height
2.0L . . . . . . . . . . . . . . . . . . . . . . . . . . 1.580 inches
2.4L . . . . . . . . . . . . . . . . . . . . . . . . . . 1.496 inches
Valve stem diameter
Intake . . . . . . . . . . . . . . . . . . . . . . . . . . ..0.234 to 0.235 inch
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . ...0.233 to 0.234 inch
Valve stem-to-guide clearance
Intake . . . . . . . . . . . . . . . . . . . . . . . . . . ..0.0018 to 0.0025 inch
Exhaust. . . . . . . . . . . . . . . . . . . . . . . . . ...0.0029 to 0.0037 inch
Valve stem tip-to-spring seat surface height (valve installed - 2.0L only)
1995 and 1996
Intake. . . . . . . . . . . . . . . . . . . . . . . . . .1.891 inches
Exhaust. . . . . . . . . . . . . . . . . . . . . . . . ..1.889 inches
1997 on
Intake. . . . . . . . . . . . . . . . . . . . . . . . . .1.77 to 1.81 inches
Exhaust. . . . . . . . . . . . . . . . . . . . . . . . ..1.71 to 1.75 inches
Crankshaft and connecting rods
Crankshaft connecting rod journal
Diameter
2.0L. . . . . . . . . . . . . . . . . . . . . . . . . . 1.8894 to 1.8900 inches
2.4L. . . . . . . . . . . . . . . . . . . . . . . . . . 1.967 to 1.9685 inches
Taper and Out-of-round limit. . . . . . . . . . . . . . . . . ..0.0001 inch (maximum)
Connecting rod bearing oil clearance . . . . . . . . . . . . . . . ..0.001 to 0.0025 inch
Connecting rod endplay (side clearance) . . . . . . . . . . . . . . .0.005 to 0.015 inch
Crankshaft main bearing journal
Diameter
2.0L. . . . . . . . . . . . . . . . . . . . . . . . . ... 2.0469 to 2.0475 inches
2.4L. . . . . . . . . . . . . . . . . . . . . . . . . ... 2.3610 to 2.3625 inches
Taper and out-of-round limits. . . . . . . . . . . . . . . . . .0.0001 inch
Crankshaft main bearing oil clearance . . . . . . . . . . . . . . . .0.008 to 0.0024 inch
Crankshaft end play. . . . . . . . . . . . . . . . . . . . . . .0.0035 to 0.0094 inch
Engine block
Cylinder bore diameter. . . . . . . . . . . . . . . . . . . . . 3.4446 to 3.4452 inches
Cylinder taper and out-of-round limits . . . . . . . . . . . . . . . .0.002 inch
Pistons and piston rings
Piston diameter (nominal)' . . . . . . . . . . . . . . . . . . . ... 3.4434 to 3.4441 inches
Piston-to-bore clearance*
2.0L
1995 . . . . . . . . . . . . . . . . . . . . . . . . . ...0.0002 to 0.0015 inch
1996 on. . . . . . . . . . . . . . . . . . . . . . . . . 0.0004 to 0.0017 inch
2.4L . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.0009 to 0.0022 inch
Piston ring side clearance
2.0L
Both compression rings. . . . . . . . . . . . . . . . . . 0.0010 to 0.0026 inch
Oil ring (pack). . . . . . . . . . . . . . . . . . . . . . .0.0002 to 0.0070 inch
2.4L
Both compression rings. . . . . . . . . . . . . . . . . . 0.0011 to 0.0031 inch
Oil ring (pack). . . . . . . . . . . . . . . . . . . . . . 0.0004 to 0.0070 inch
Piston ring end gap
2.0L
Number 1 (top) compression ring. . . . . . . . . . . . . . ..0.009 to 0.020 inch
Number 2 compression ring . . . . . . . . . . . . . . . . ..0.019 to 0.031 inch
Oil control ring (side rails). . . . . . . . . . . . . . . . . ..0.009 to 0.026 inch
2.4L
Number 1 (top) compression ring. . . . . . . . . . . . . . ..0.0098 to 0.020 inch
Number 2 compression ring . . . . . . . . . . . . . . . . ..0.009 to 0.018 inch
Oil control ring (side rails). . . . . . . . . . . . . . . . . ..0.0098 to 0.025 inch
"Measured
11/16-inch up from the bottom
of
the piston skirt on
2.0L
engines and 9/16-inch up from the bottom
of
the piston skirt on
2.4L
engines.
Chapter 2 Part C General engine overhaul procedures
2C-3
Torque specifications**
Ft-lbs (unless otherwise indicated)
Balance shaft carrier-to-engine bolts. . . . . . . . . . . . . . . .. 40
Balance shaft chain tensioner and guide fasteners. . . . . . . . . . .105 in-lbs
Balance shaft gear cover stud (double-ended). . . . . . . . . . . . 105 in-lbs
Balance shaft rear cover bolts. . . . . . . . . . . . . . . . . . . 105 in-lbs
Balance shaft sprocket bolts . . . . . . . . . . . . . . . . . . ... 250 in-lbs
Main bearing cap assembly bolts
2.0L
Main cap bolts (Ml 1) . . . . . . . . . . . . . . . . . . . .60
Bedplate bolts (M8). . . . . . . . . . . . . . . . . . . ... 22
2.4L
Main cap bolts (M11)
Step 1. . . . . . . . . . . . . . . . . . . . . . . ... 30
Step 2. . . . . . . . . . . . . . . . . . . . . . . .. Tighten an additional 90-degrees (1/4 turn)
Bedplate bolts (M8) . . . . . . . . . . . . . . . . . . . ...250 in-lbs
Connecting rod cap bolts
Step 1. . . . . . . . . . . . . . . . . . . . . . . . . . ..20
Step 2. . . . . . . . . . . . . . . . . . . . . . . . . . . Tighten an additional 90-degrees (1/4 turn)
"Note: Refer to Chapter 2 Part A for additional torque specifications.
V6 engine
General
Bore. . . . . . . . . . . . . . . . . . . . . . . . . . . . ..3.29 inches
Stroke. . . . . . . . . . . . . . . . . . . . . . . . . . . ...2.992 inches
Displacement. . . . . . . . . . . . . . . . . . . . . . . . ... 152 cubic inches (2.5 liters)
Firing order . . . . . . . . . . . . . . . . . . . . . . . . . ...1-2-3-4-5-6
Compression ratio. . . . . . . . . . . . . . . . . . . . . . . 9.4:1
Compression pressure. . . . . . . . . . . . . . . . . . . . . .178 psi @ 250 rpm
Oil pressure
At idle speed . . . . . . . . . . . . . . . . . . . . . . . ...6 psi (minimum)
At 3000 rpm. . . . . . . . . . . . . . . . . . . . . . . . 35 to 75 psi
Valves and related components
Face angle. . . . . . . . . . . . . . . . . . . . . . . . . . 45 to 45-1/2 degrees
Seat angle. . . . . . . . . . . . . . . . . . . . . . . . . . 44 to 44-1/2 degrees
Valve margin width
Intake
Standard . . . . . . . . . . . . . . . . . . . . . . . . 0.039 inch
Service limit. . . . . . . . . . . . . . . . . . . . . . ...0.019 inch
Exhaust
Standard. . . . . . . . . . . . . . . . . . . . . . . . 0.047 inch
Service limit. . . . . . . . . . . . . . . . . . . . . . ...0.028 inch
Valve stem diameter . . . . . . . . . . . . . . . . . . . . . . 0.236 inch
Valve stem-to-guide clearance
Intake
Standard. . . . . . . . . . . . . . . . . . . . . . . . 0.0008 to 0.0020 inch
Service limit. . . . . . . . . . . . . . . . . . . . . . ...0.004 inch
Exhaust
Standard. . . . . . . . . . . . . . . . . . . . . . . . 0.0016 to 0.0028 inch
Service limit . . . . . . . . . . . . . . . . . . . . . . ...0.006 inch
Valve spring
Free length (approximate) . . . . . . . . . . . . . . . . . . ...2.01 inches
Service limit . . . . . . . . . . . . . . . . . . . . . . ...1.97 inches
Installed height. . . . . . . . . . . . . . . . . . . . . . . 1.74 inches
Crankshaft and connecting rods
crankshaft connecting rod journal
Diameter. . . . . . . . . . . . . . . . . . . . . . . . . . 1.968 to 1.969 inches
Out-of-round limit . . . . . . . . . . . . . . . . . . . . . ...0.001 inch (maximum)
Taper limit. . . . . . . . . . . . . . . . . . . . . . . . ...0.0002 inch (maximum)
Connecting rod bearing oil clearance
1995 through 1997. . . . . . . . . . . . . . . . . . . . . . 0.0008 to 0.0028 inch
1998 on. . . . . . . . . . . . . . . . . . . . . . . . . ...0.0006 to 0.0018 inch
connecting rod endplay (side clearance)
Standard. . . . . . . . . . . . . . . . . . . . . . . . . . 0.004 to 0.010 inch
Service limit. . . . . . . . . . . . . . . . . . . . . . . . 0.016 inch
2C
2C-4
Chapter 2 Part C General engine overhaul procedures
V6 engine (continued)
Crankshaft and connecting rods
Crankshaft main bearing journal
Diameter. . . . . . . . . . . . . . . . . . . . . . . . . .2.361 to 2.362 inches
taper and out-of-round limits . . . . . . . . . . . . . . . . . ..0.0001 inch
Crankshaft end play
Standard. . . . . . . . . . . . . . . . . . . . . . . . . .0.002 to 0.010 inch
Service limit. . . . . . . . . . . . . . . . . . . . . . . . 0.012 inch
Crankshaft main bearing oil clearance
Standard. . . . . . . . . . . . . . . . . . . . . . . . . .0.0008 to 0.0016 inch
Service limit. . . . . . . . . . . . . . . . . . . . . . . . 0.0039 inch
Engine block
Cylinder bore diameter. . . . . . . . . . . . . . . . . . . . . 3.29 inches
Flatness of top surface. . . . . . . . . . . . . . . . . . . . . 0.002 inch
Service limit. . . . . . . . . . . . . . . . . . . . . . . . 0.004 inch
Pistons and piston rings
Piston diameter (nominal)* . . . . . . . . . . . . . . . . . . . ... 3.29 inches
Piston-to-bore clearance. . . . . . . . . . . . . . . . . . . . .0.0008 to 0.0016 inch
Piston ring side clearance
Number 1 (top) compression ring
Standard. . . . . . . . . . . . . . . . . . . . . . . . 0.0012 to 0.0028 inch
Service limit. . . . . . . . . . . . . . . . . . . . . . ...0.004 inch
Number 2 compression ring
Standard. . . . . . . . . . . . . . . . . . . . . . . . 0.0007 to 0.0024 inch
Service limit. . . . . . . . . . . . . . . . . . . . . . ...0.004 inch
Oil control ring . . . . . . . . . . . . . . . . . . . . . . . .Loose fit
Piston ring end gap
Number 1 (top) compression ring
Standard. . . . . . . . . . . . . . . . . . . . . . . . 0.010 to 0.016 inch
Service limit . . . . . . . . . . . . . . . . . . . . . . ...0.031 inch
Number 2 compression ring
Standard. . . . . . . . . . . . . . . . . . . . . . . . 0.016 to 0.022 inch
Service limit . . . . . . . . . . . . . . . . . . . . . . ...0.031 inch
Oil control ring (side rails)
Standard. . . . . . . . . . . . . . . . . . . . . . . . 0.006 to 0.019 inch
Service limit . . . . . . . . . . . . . . . . . . . . . . ...0.039 inch
*Measured
0.080 inch up from the bottom
of
the piston skirt.
Torque specifications**
Ft-lbs (unless otherwise indicated)
Main bearing cap bolts . . . . . . . . . . . . . . . . . . . . . 69
Connecting rod cap nuts. . . . . . . . . . . . . . . . . . . . . 38
**Note: Refer to Part
B of
this Chapter for
additional
torque specifications.
1
General information
Included in this portion of Chapter 2 are
the general overhaul procedures for the cylin-
der head and internal engine components.
The information ranges from advice concern-
ing preparation for an overhaul and the pur-
chase of replacement parts to detailed, step-
by-step procedures covering removal and
installation of internal engine components
and the inspection of parts.
The following Sections have been written
based on the assumption that the engine has
been removed from the vehicle. For informa-
tion concerning in-vehicle engine repair, as
well as removal and installation of the external
components necessary for the overhaul, see
the applicable Part of this Chapter. For infor-
mation on determining models and engine
numbers, refer to the Vehicle Identification
Numbers at the beginning of this manual.
The Specifications included in this Part
are only those necessary for the inspection
and overhaul procedures which follow. Refer
to Part A or B for additional Specifications as
applicable.
2
Engine overhaul - general
information
Refer to illustration 2.4
It's not always easy to determine when, or
if, an engine should be completely overhauled,
as a number of factors must be considered.
High mileage is not necessarily an indi-
cation that an overhaul is needed, while low
mileage doesn't preclude the need for an
overhaul. Frequency of servicing is probably
the most important consideration. An engine
that's had regular and frequent oil and filter
changes, as well as other required mainte-
nance, will most likely give many thousands
of miles of reliable service. Conversely, a
neglected engine may require an overhaul
very early in its life.
Excessive oil consumption is an indica-
tion that piston rings, valve seals andlor valve
guides are in need of attention. Make sure
that oil leaks aren't responsible before decid-
ing that the rings andlor guides are bad. Per-
form a compression check to determine the
extent of the work required (see Section 4).
Check the oil pressure with a gauge
installed in place of the oil pressure sending
unit, located above the oil filter (see illustra-
tion), and compare the pressure to the pres-
sure listed in this Chapter's Specifications. If
it's extremely low, the bearings andlor oil
pump are probably worn out.
Loss of power, rough running, knocking
or metallic engine noises, excessive valve
train noise and high fuel consumption rates
may also point to the need for an overhaul,
especially if they're all present at the same
ti me. If a complete tune-up doesn't remedy
the situation, major mechanical work is the
only solution.
An engine overhaul involves restoring
the internal parts to the specifications of a
new engine. During an overhaul, the piston
Chapter 2 Part C General engine overhaul procedures
2C-5
2.4 The engine oil pressure sending unit
is located above the oil filter (V6 engine
shown, four-cylinder engine similar)
rings are replaced and the cylinder walls are
reconditioned (rebored andlor honed). If a re-
bore is done by an automotive machine shop,
new oversize pistons will also be installed.
The main bearings, connecting rod bearings
and camshaft bearings are generally replaced
with new ones and, if necessary, the
crankshaft may be reground to restore the
journals. Generally, the valves are serviced as
well, since they're usually in less-than-perfect
condition at this point. While the engine is
being overhauled, other components, such
as the distributor, starter and alternator, can
be rebuilt as well. The end result should be a
li ke-new engine that will give many trouble
free miles. Note: Critical cooling system com-
ponents such as the hoses, drivebelts, ther-
mostat and water pump MUST be replaced
with new parts when an engine is overhauled.
The radiator should be checked carefully to
ensure that it isn't clogged or leaking (see
Chapter 3). Also, we don't recommend over-
hauling the oil pump - always install a new
one when an engine is rebuilt.
Before beginning the engine overhaul,
read through the entire procedure to familiar-
ize yourself with the scope and requirements
of the job. Overhauling an engine isn't diffi-
cult, but it is time consuming. Plan on the
vehicle being tied up for a minimum of two
weeks, especially if parts must be taken to an
automotive machine shop for repair or recon-
ditioning. Check on availability of parts and
make sure that any necessary special tools
and equipment are obtained in advance.
Most work can be done with typical hand
tools, although a number of precision mea-
suring tools are required for inspecting parts
to determine if they must be replaced. Often
an automotive machine shop will handle the
inspection of parts and offer advice concern-
ing reconditioning and replacement. Note:
Always wait until the engine has been com-
pletely disassembled and all components,
especially the engine block, have been
inspected before deciding what service and
repair operations must be performed by an
automotive machine shop. Since the block's
condition will be the major factor to consider
when determining whether to overhaul the
original engine or buy a rebuilt one, never
purchase parts or have machine work done
on other components until the block has been
thoroughly inspected. As a general rule, time
is the primary cost of an overhaul, so it does-
n't pay to install worn or sub-standard parts.
As a final note, to ensure maximum life
and minimum trouble from
a
rebuilt engine,
everything must be assembled with care in a
spotlessly clean environment.
3
Top Dead Center (TDC) for
number one piston - locating
Note: The crankshaft timing marks on these
engines aren't visible until after the timing belt
cover(s) have been removed.
1
Top Dead Center (TDC) is the highest
point in the cylinder that each piston reaches
as it travels up-and-down when the
crankshaft rotates. Each piston reaches TDC
on the compression stroke and again on the
exhaust stroke, but TDC generally refers to
the piston position on the compression
stroke. The cast-in timing mark on the
crankshaft timing belt sprocket installed on
the front of the crankshaft is referenced to
the number 1 piston. When the mark on the
crankshaft timing belt sprocket is aligned
with the cast-in timing mark on the oil pump
housing and the timing marks on the
camshaft sprockets align with their respec-
tive marks (see Section 6 of the appropriate
Part of this Chapter), the number 1 piston is
at TDC on the compression stroke.
2
In order to bring any piston to TDC, the
crankshaft must be rotated manually. When
looking at the front of the engine (drivebelt
end), normal crankshaft rotation is clockwise.
DO NOT rotate the engine counterclockwise
as the crankshaft timing belt sprocket may
jump a tooth, requiring timing belt removal.
3
The preferred method is to turn the
crankshaft with a large socket and breaker bar
attached to the crankshaft damperlpulley bolt
that is threaded into the front of the crankshaft.
4
Remove all (accessible) spark plugs as
this will make it easier to rotate the engine by
hand (see Chapter 1 if necessary). Note: On
V6 engines, the spark plugs for cylinders 1, 3
and 5 are located under the upper intake
manifold and not easily accessible. Unless
they are required to be removed, depending
on what procedure you are performing, leave
them installed.
5
Disconnect the battery cable from the
remote negative battery terminal.
6
Remove the accessory drivebelt splash
shield (see Chapter 1) to gain access to the
crankshaft damperlpulley bolt.
Four-cylinder engines
Refer to illustration 3.9
7
Install a compression gauge (screw-in
type with a hose) in the number 1 cylinder
spark plug hole. Place the gauge dial where
you can see it while turning the crankshaft
damperlpulley bolt. Note: On 4 cylinder
engines the number 1 cylinder is located at
the front (drivebelt end) of the engine.
8
Rotate the crankshaft clockwise until you
see compression building up on the gauge -
indicating you are on the compression stroke.
9
On 2.0L engines, remove the access
hole plug on the timing belt cover (see illus-
tration). Slowly turn the crankshaft until the
camshaft sprocket timing mark is visible
through the access hole. Using a flashlight,
look inside the access hole to locate the
camshaft timing mark on the timing belt rear
cover. Slowly rotate the crankshaft clockwise
as required until the timing mark on the
camshaft sprocket aligns with the arrow on
the timing belt rear cover. The crankshaft is
now located at number 1 piston TDC on the
compression stroke. Note: If you turn the
crankshaft too far, it will be necessary to
rotate the crankshaft clockwise 1-3/4 turns to
approach the compression stroke again.
10
On 2.4L engines, remove the timing belt
upper cover (see Chapter 2A, Section 6).
Rotate the crankshaft clockwise until the
camshaft sprocket timing marks are aligned
(see illustration 6.9b in Chapter 2 Part A).
The crankshaft is now located at number 1
piston TDC on the compression stroke. Note:
If you turn the crankshaft too far, it will be
necessary to rotate the crankshaft clockwise
approximately 1-3/4 turns to approach the
compression stroke again.
11
After the number 1 piston has been posi-
tioned at TDC on the compression stroke,
TDC for the remaining pistons can be located
by turning the crankshaft exactly 180 degrees
(1/2 turn) from that position, following the
spark plug firing order; i.e. the first 180 degree
rotation from number 1 piston TDC will bring
the number 3 cylinder piston to TDC on it's
compression stroke, another 180 degree rota-
tion will bring the number 4 cylinder piston to
TDC on it's compression stroke, etc.
3.9 2.0L four-cylinder models have an
access hole in the front timing belt cover
so you can see the camshaft timing marks
without removing the cover
2C
2C-6
Chapter 2 Part C General engine overhaul procedures
V6 engine
Note: This method assumes that the upper
intake manifold is installed, making the num-
ber 1 spark plug inaccessible.
12 Install a compression gauge (screw-in
type with a hose) in the number 6 cylinder
spark plug hole. Place the gauge dial where
you can see it while turning the crankshaft
damperlpulley bolt. Note: The number six
cylinder is located at the rear (transaxle end)
of the left cylinder bank (refer to the Specifi-
cations in Chapter 1, if necessary).
13
Rotate the crankshaft clockwise until you
see compression building up on the gauge -
indicating you are on the compression stroke.
14
Remove the upper left timing belt cover
(see illustration 6.6 in Chapter 2 Part B).
Note: If the number 6 piston is near TDC, the
camshaft timing mark should be approxi-
mately 60 degrees counterclockwise of the
timing mark on the valve cover.
15
Rotate the crankshaft clockwise until the
ti ming mark on the left camshaft sprocket
li nes up with the timing mark on the valve
cover (see illustration 6.11a in Chapter 2
Part B). The crankshaft is now located at
number 1 piston TDC on the compression
stroke. Note: If you turn the crankshaft too far,
it will be necessary to rotate the crankshaft
clockwise approximately 1-3/4 turns
to
approach the compression stroke again.
16
After the number 1 piston has been posi-
tioned at TDC on the compression stroke,
TDC for the remaining pistons can be located
by turning the crankshaft exactly 120 degrees
from that position, following the spark plug fir-
ing order; i.e. the first 120 degree rotation
from number 1 piston TDC will bring the num-
ber 2 cylinder piston to TDC on it's compres-
sion stroke, another 120 degree rotation will
bring the number 3 cylinder piston to TDC on
it's compression stroke, etc.
4
Compression check
Note: On V6 engines it is necessary to
remove the upper intake manifold to access
the right bank of spark plugs, refer to Part B
of this Chapter.
1
A compression check will tell you the
mechanical condition of the upper end (pis-
tons, rings, valves, head gasket) of your
engine. Specifically, it can tell you if the com-
pression is low due to leakage caused by
worn piston rings, defective valves and seats
or a blown head gasket. Note: The engine
must be at normal operating temperature and
the -battery must be fully charged for this
check to be accurate.
2
Begin by cleaning the area around the
spark plugs before you remove them (com-
pressed air should be used, if available, oth-
erwise a small brush or even a bicycle tire
pump will work). The idea is to prevent dirt
from getting into the cylinders as the com-
pression check is being performed.
3
Remove all of the spark plugs from the
engine (Chapter 1).
4
Block the throttle wide open.
5
Disable the ignition by disconnecting the
primary (low voltage) wire electrical connec-
tor from the ignition coil pack (four-cylinder
engines) or the disconnecting the 2 pin con-
nector from the distributor (V6 engine) (see
Chapter 5).
6
Install the compression gauge in the
number one spark plug hole.
7
Crank the engine over at least seven
compression strokes and watch the gauge.
The compression should build up quickly in a
healthy engine. Low compression on the first
stroke, followed by gradually increasing pres-
sure on successive strokes, indicates worn
piston rings. A low compression reading on
the first stroke, which doesn't build up during
successive strokes, indicates leaking valves
or a blown head gasket (a cracked head
could also be the cause). Deposits on the
undersides of the valve heads can also cause
low compression. Record the highest gauge
reading obtained.
8
Repeat the procedure for the remaining
cylinders and compare the results to the
Specifications in this Chapter.
9
Add some engine oil (about three squirts
from a plunger-type oil can) to each cylinder,
through the spark plug hole, and repeat the
test recording the results.
10 If the compression increases after the oil
is added, the piston rings are definitely worn.
If the compression doesn't increase signifi-
cantly, the leakage is occurring at the valves
or head gasket. Leakage past the valves may
be caused by burned valve seat(s), andlor
faces or warped, cracked or bent valve(s).
11
If two adjacent cylinders have equally
low compression, there's a strong possibility
that the head gasket between them is blown.
The appearance of coolant in the combustion
chambers or the crankcase would verify this
condition.
12 If one cylinder is 20 percent lower than
the others, and the engine has a slightly
rough idle, a worn exhaust lobe on the
camshaft could be the cause.
13 If the compression is unusually high, the
combustion chambers are probably coated
with carbon deposits. If that's the case, the
cylinder head should be removed and de-
carbonized.
14 If compression is way down or varies
greatly between cylinders, it would be a good
idea to have a leak-down test performed by
an automotive repair shop. This test will pin-
point exactly where the leakage is occurring
and determine how severe it is.
5
Vacuum gauge diagnostic
checks
Refer to illustration 5.6
1
A vacuum gauge provides valuable
information about what is going on in the
engine at a low-cost. You can check for worn
rings or cylinder walls, leaking head or intake
manifold gaskets, restricted exhaust, stuck or
burned valves, weak valve springs, improper
ignition or valve timing and ignition problems.
2
Unfortunately, vacuum gauge readings
are easy to misinterpret, so they should be
used in conjunction with other tests to con-
firm the diagnosis.
3
Both the absolute readings and the rate
of needle movement are important for accu-
rate interpretation. Most gauges measure
vacuum in inches of mercury (in-Hg). The fol-
lowing references to vacuum assume the
diagnosis is being performed at sea level. As
elevation increases (or atmospheric pressure
decreases), the reading will decrease. For
every 1,000 foot increase in elevation above
approximately 2000 feet, the gauge readings
will decrease about one inch of mercury.
4
Connect the vacuum gauge directly to
intake manifold vacuum, not to ported (throt-
tle-body) vacuum. Be sure no hoses are left
disconnected during the test or false read-
ings will result.
5
Before you begin the test, allow the
engine to warm up completely. Block the
wheels and set the parking brake. With the
transmission in neutral (or Park, on automat-
ics), start the engine and allow it to run at
normal idle speed. Warning: Carefully
inspect the fan blades for cracks or damage
before starting the engine. Keep your hands
and the vacuum tester clear of the fan and do
not stand in front of the vehicle or in line with
the fans when the engine is running.
6
Read the vacuum gauge; an average,
healthy engine should normally produce
about 17 to 22 inches of vacuum with a fairly
steady needle. Refer to the following vacuum
gauge readings and what they indicate about
the engines condition (see illustration).
7
A low steady reading usually indicates a
leaking gasket between the intake manifold
and throttle body, a leaky vacuum hose, late
ignition timing or incorrect camshaft timing.
Check ignition timing with a timing light and
eliminate all other possible causes, utilizing
the tests provided in this Chapter before you
remove the timing belt cover to check the
ti ming marks.
8
If the reading is 3 to 8 inches below nor-
mal and it fluctuates at that low reading, sus-
pect an intake manifold gasket leak at an
intake port or a faulty injector.
9
If the needle has regular drops of about 2
to 4 inches at a steady rate the valves are
probably leaking. Perform a compression or
leak-down test to confirm this.
10
An irregular drop or down-flick of the
needle can be caused by a sticking valve or
an ignition misfire. Perform a compression or
leak-down test. Check the condition of the
spark plugs and compare them to the chart
on the back cover of this manual.
11
A rapid vibration of about 4 in-Hg vibra-
tion at idle combined with exhaust smoke
indicates worn valve guides. Perform a leak-
down test to confirm this. If the rapid vibra-
tion occurs with an increase in engine speed,
check for a leaking intake manifold gasket or
head gasket, weak valve springs, burned
valves or ignition misfire.
Chapter 2 Part C General engine overhaul procedures
2C-7
Low , steady reading
Low, fluctuating needle
Regular drops
5.6 Typical vacuum gauge diagnostic readings
Irregular drops
Rapid vibration
12
A slight fluctuation, say 1 inch up-and-
down, may mean ignition problems. Check all
the usual tune-up items and, if necessary, run
the engine on an ignition system analyzer.
13 If there is a large fluctuation, perform a
compression or leak-down test to look for a
weak or dead cylinder or a blown head gasket.
14 If the needle moves slowly through a
wide range, check for a clogged PCV system,
inoperative or clogged fuel injectors), throttle
body or intake manifold gasket or vacuum
hose leaks.
15
Check for a slow return after revving the
engine by quickly snapping the throttle open
until the engine reaches about 2,500 rpm and
let it shut. Normally the reading should drop
to near zero, rise above normal idle reading
(about 5 in-Hg over) and then return to the
previous idle reading. If the vacuum returns
slowly and doesn't peak when the throttle is
snapped shut, the rings may be worn. If there
is a long delay, look for a restricted exhaust
system (often the muffler or catalytic con-
verter). An easy way to check this is to tem-
porarily disconnect the exhaust ahead of the
suspected part and repeat the test.
6
Engine removal - methods and
precautions
If you've decided that an engine must be
removed for overhaul or major repair work,
several preliminary steps should be taken.
Locating a suitable place to work is
extremely important. Adequate work space,
along with storage space for the vehicle, will
be needed. If a shop or garage isn't available,
at the very least a flat, level, clean work sur-
face made of concrete or asphalt is required.
Cleaning the engine compartment and
engine before beginning the removal proce-
dure will help keep tools clean and organized.
An engine hoist or A-frame will also be
necessary. Make sure the equipment is rated
in excess of the combined weight of the
engine and accessories. Safety is of primary
importance, considering the potential hazards
involved in lifting the engine out of the vehicle.
If the engine is being removed by a
novice, a helper should be available. Advice
and aid from someone more experienced
would also be helpful. There are many
instances when one person cannot simulta-
neously perform all of the operations required
when lifting the engine out of the vehicle.
Plan the operation ahead of time.
Arrange for, or obtain all of the tools and
equipment you'll need prior to beginning the
job. Some of the equipment necessary to per-
form engine removal and installation safely
and with relative ease are (in addition to an
engine hoist) a heavy duty floor jack, complete
sets of wrenches and sockets as described in
the front of this manual, wooden blocks and
plenty of rags and cleaning solvent for mop-
ping up spilled oil, coolant and gasoline. If the
hoist must be rented, make sure that you
arrange for it in advance and perform all of the
operations possible without it beforehand.
This will save you time and money.
Plan for the vehicle to be out of use for
quite a while. A machine shop will be
required to perform some of the work which
the do-it-yourselfer can't accomplish without
special equipment. These shops often have a
busy schedule, so it would be a good idea to
consult them before removing the engine in
order to accurately estimate the amount of
ti me required to rebuild or repair components
that may need work.
Always be extremely careful when remov-
ing and installing the engine. Serious injury can
result from careless actions. Plan ahead, take
your time and a job of this nature, although
major, can be accomplished successfully.
7
Engine - removal and installation
Note 1: Read through the entire Section
before beginning this procedure. The engine
and transaxle are removed from the vehicle as
an assembly and separated once outside of
the vehicle.
Note 2: The engineltransaxle assembly is
designed to be removed from the underside
of the vehicle. This manual assumes that the
do-it-yourselfer is performing the job at home
and is removing the engine without the use of
a vehicle lift.
Warning: These models have airbags. Always
disable the airbag system and wait 2 minutes
before working in the vicinity of the impact
sensors, steering column or instrument panel
to avoid the possibility of accidental deploy-
ment of the airbags, which could cause per-
sonal injury (see Chapter 12).
Removal
Refer to illustration 7.10
1
If the vehicle is equipped with air condi-
tioning, have the system discharged by a
dealer service department or automotive air
conditioning service facility.
2
Place protective covers on the front
fenders and cowl. Special fender covers are
available, but an old bedspread or blanket
will also work.
3
Remove the hood (see Chapter 11).
4
Perform the fuel system pressure relief
procedure (see Chapter 4).
5
Disconnect the negative battery cable
from the ground stud on the left shock tower
(see Chapter 5, Section 1).
6
Remove the air cleaner assembly (see
Chapter 4).
7
Raise the vehicle and support it securely
on jackstands. Drain the cooling system,
engine oil and transaxle fluid (see Chapter 1).
8
Remove the engine cooling fans, radia-
tor and air conditioning condenser unit Of
equipped) (see Chapter 3).
9
Remove the front bumper fascia and
reinforcement bar (see Chapter 11).
10
Carefully label, then disconnect all vac-
uum lines, coolant and emissions hoses, wire
2C
2C-8
Chapter 2 Part C General engine overhaul procedures
7.10 Label both ends of each wire or
vacuum connection before
separating them
harness connectors and brackets connected
to the engine. Masking tape and felt-tip pens
work well for marking items (see illustration).
If necessary, take instant photos or sketch
the locations to ensure correct location at
installation.
11
Detach the Powertrain Control Module
(PCM), Power Distribution Center (PDC) and
Transmission Control Module (TCM) (if
equipped) from their mountings and position
them out of the way. Caution: The PCM and
TCM are Electro-Static Discharge (ESD) sen-
sitive electronic devices, meaning a static dis-
charge from your body could possibly dam-
age internal electrical components. Make
sure to properly ground yourself and the con-
trol modules before handling them. Avoid
touching the electrical terminals unless abso
-
lutely necessary.
12
Disconnect the fuel line from the fuel
injection system (see Chapter 4). Cap the fit-
tings to prevent leakage and contamination.
13
Detach the accelerator cable and cruise
control cable (if equipped) (see Chapter 4).
14 If equipped, remove the oil pan-to-
transaxle structural collar (see Chapter 2A).
15
On manual transaxle equipped models,
detach the shift cables (see Chapter 7A) and
the clutch release cable (see Chapter 8).
16
On automatic transaxle equipped vehi-
cles, detach the shift control cable and oil
cooler lines from the transaxle (see Chap-
ter 7B). After removing the oil cooler lines,
plug the ends to prevent leakage and con-
tamination.
17
Clearly label and disconnect all electri-
cal connections and ground straps (where
applicable) from the transaxle.
18
Remove the driveaxles from the
transaxle (see Chapter 8). Stuff clean rags
into the transaxle openings to prevent leak-
age and contamination.
19
Remove the bellhousing lower cover,
match-mark the torque converter or modular
clutch assembly (as applicable) to the drive-
plate and remove the four bolts (refer to the
appropriate Part of Chapter 7).
20
Disconnect the exhaust system from the
exhaust manifold (see Chapter 4).
21
On V6 models, remove the cross-over
tube connecting the exhaust manifolds (see
Chapter 2B).
22
Remove the drivebelts (see Chapter 1).
23 If equipped, remove the air conditioning
compressor (see Chapter 3).
24
Detach the power steering pump, reser-
voir and the power steering lines (mounted to
the rear cylinder head) from the brackets
without disconnecting the hoses and position
them out of the way.
25
Remove the through-bolt from the rear
engine mount (refer to the appropriate Part of
Chapter 2).
26
Disconnect the ground straps from the
engine.
27
Lower the vehicle.
28
Attach a chain or an engine lifting fixture
to the engine lifting brackets (or to bolts
which are securely mounted in the cast iron
block or accessory mounting bracket) and
attach the hoist. Take up the slack until there
is tension on the chain to support the
engineltransaxle assembly. Warning: Attach-
ing the engine lifting chain to a bolt or stud
located in an aluminum component (such as
the cylinder head) may not provide the neces-
sary strength to support the weight of the
engineltransaxle assembly during removal.
29
Support the transaxle with a floor jack.
Place a block of wood on the jack pad to pro-
tect the transaxle. Warning: Do not place any
part of your body under the engineltransaxle
when it's supported only by a hoist or other
lifting device.
30
Remove the mount through-bolts on all
of the engine or transaxle mounts (refer to the
appropriate Part of Chapter 2).
31
Confirm that all of the cables, hoses,
wires and other items are disconnected from
the engineltransaxle.
32
Carefully push the transaxle down, or
adjust the engine lifting fixture to position the
engine slightly higher than the transaxle,
while lifting the engine up to clear obstruc-
tions.
33
Lift the engine and transaxle high
enough to clear the front of the vehicle and
slowly move the hoist away.
34
Lower the hoist and set the transaxle on
blocks - leave the hoist hooked to the engine.
35
With the transaxle securely supported,
remove the transaxle-to-engine bolts and
separate the engine from the transaxle (refer
to Chapter 7 if necessary).
36
Remove the driveplate (refer to the
appropriate Part of Chapter 2) and then
remove the engine rear plate. Mount the
engine on an engine stand.
Installation
37
Before installing the engine assembly,
inspect the engineltransaxle mounts. If
they're worn or damaged, replace them.
38
On manual transaxle equipped models,
inspect the modular clutch assembly (see
Chapter 8) and apply a very small amount of
high temperature grease to the transaxle
input shaft splines.
39
On automatic transaxle equipped vehi-
cles, inspect the torque converter/input shaft
seal.
40
Carefully mate the transaxle to the
engine following the procedure outlined in
Chapter 7. Caution: Do not use the bolts to
force the engine and transaxle into alignment.
It may crack or damage major components.
41
Install the transaxle-to-engine bolts and
tighten them to the torque listed in the Speci-
fications of Chapter 7.
42
Attach the hoist to the engine and care-
fully lower the engineltransaxle assembly into
the vehicle.
43 Install the engineltransaxle mount bolts
and tighten them securely.
44
The remaining installation steps are the
reverse of removal.
45
After lowering the vehicle, add coolant,
engine oil, power steering and transmission
fluid/lubricant as needed (see Chapter 1).
46
Run the engine and check for proper
operation and leaks. Shut off the engine and
recheck the fluid levels. Note: If the engine
has just been rebuilt, see Section 27 for
break-in procedures.
8
Engine rebuilding alternatives
The do-it-yourselfer is faced with a num-
ber of options when performing an engine
overhaul. The decision to replace the engine
block, piston/connecting rod assemblies and
crankshaft depends on a number of factors,
with the number one consideration being the
condition of the block. Other considerations
are cost, access to machine shop facilities,
parts availability, time required to complete
the project and the extent of prior mechanical
experience on the part of the do-it-yourselfer.
Some of the rebuilding alternatives
include:
Individual parts - If the inspection pro-
cedures reveal that the engine block and
most engine components are in reusable
condition, purchasing individual parts may be
the most economical alternative. The block,
crankshaft and piston/connecting rod assem-
blies should all be inspected carefully. Even if
the block shows little wear, the cylinder bores
should be surface honed.
Short block - A short block' consists of
an engine block with a crankshaft and pis-
ton/connecting rod assemblies already
installed. All new bearings are incorporated
and all clearances will be correct. The exist-
ing camshaft, valve train components, cylin-
der head(s) and external parts can be bolted
to the short block with little or no machine
shop work necessary.
Long block - A long block consists of a
short block plus an oil pump, oil pan, cylinder
head, rocker arm cover, camshaft(s) and
valve train components, timing sprockets and
ti ming covers. All components are installed
with new bearings, seals and gaskets incor-
porated throughout. The installation of mani-
folds and external parts is all that's neces-
sary.
Give careful thought to which alternative
is best for you and discuss the situation with
Chapter 2 Part C General engine overhaul procedures
2C-9
local automotive machine shops, auto parts
dealers and experienced rebuilders before
ordering or purchasing replacement parts.
9
Engine overhaul - disassembly
sequence
Refer to illustrations 9.5a, 9.5b and 9.5c
1
It's much easier to disassemble and
work on the engine if it's mounted on a
portable engine stand. A stand can often be
rented quite cheaply from an equipment
rental yard. Before the engine is mounted on
a stand, the driveplate must be removed from
the engine.
2
If a stand isn't available, it's possible to
disassemble the engine with it blocked up on
the floor. Be extra careful not to tip or drop
the engine when working without a stand.
3
If you're going to obtain a rebuilt engine,
all external components must be removed
from the old engine first, to be transferred to
the replacement engine, just as they will if
you're doing a complete engine overhaul
yourself. These include but are not limited
too:
Air conditioning compressor and
brackets
Alternator and brackets
Coil pack or distributor, spark plug wires
and spark plugs
Driveplate
Electronic engine control components
Emissions control components
Engine mounts
Fuel injection components
Intake and exhaust manifolds
Oil filter (and adapter if equipped)
Power steering pump and brackets
Thermostat cover, thermostat and
housing
Water pump
Note: When removing the external compo-
nents from the engine, pay close attention to
details that may be helpful or important dur-
ing installation. Note the installed position of
gaskets, seals, spacers, pins, brackets, wash-
ers, bolts and other small items.
4
If you're obtaining a short block, which
consists of the engine block, crankshaft, pis-
tons and connecting rods all assembled, then
the cylinder head, oil pan and oil pump will
have to be removed as well. See Engine
rebuilding alternatives for additional informa-
tion regarding the different possibilities to be
considered.
5
If you're planning a complete overhaul,
the engine must be disassembled and the
internal components removed in the general
following order (see illustrations):
Intake and exhaust manifolds
Valve cover
Rocker arms and shafts (SOHC engine)
Timing belt covers
Timing belt and sprockets
Camshaft(s)
Rocker arms and hydraulic lash
adjusters (DOHC engines)
PISTON AND
CONNECTING ROD
ASSEMBLY
CONNECTING
ROD BEARINGS
SEAL
OIL PASSAGE
0-RING
SEAL
UPPER
BEARING
NIPPLE
(GROOVED)
OIL FILTER
ADAPTER
9.5a Engine block components - 2.0L four-cylinder
9.5b Engine block components - 2.4L four-cylinder
2C
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