3
1

6

Figure 1:
Manifold Absolute Pressure (MAP) Sensor (1),
MAP Sensor Electrical Connector (6),
MAP Sensor Mounting Bolt (3),
Upper Intake Manifold (4)
1
6

5

Figure 2:
Manifold Absolute Pressure (MAP) Sensor (1),
MAP Sensor O-Ring Seal (5),
MAP Sensor Electrical Connector (6)

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and Fuel Components Service Manual

Page 83 of 117

INSTALLATION PROCEDURE
1. Lightly coat MAP Sensor O-Ring Seal (5)
with clean engine oil before installing sensor.
Figure 2

2.
3.

4.
5.

Apply clean engine oil with a sponge or a
brush. To prevent sensor blockage, avoid
dipping MAP Sensor port directly into
liquid.
Install MAP Sensor (1) on Upper Intake
Manifold (4). Figure 1
Install MAP Sensor Mounting Bolt (3) and
tighten. Figure 1. Refer to Electrical
Component & Sensor Torque
Specifications.
Connect MAP Sensor Electrical Connector
(6) to Engine Harness Connector (2).
Figures 1 & 2
Verify proper operation.

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and Fuel Components Service Manual

Page 84 of 117

Oil Pan Replacement
REMOVAL PROCEDURE
1. Secure vehicle on approved hoist and
raise vehicle.
2. Remove Oil Dipstick Tube Bolt and
release Tube from bottom Clip. Follow
OEM procedure.
3. Remove Oil Dipstick Tube from Oil Pan
and secure out of the way.
4. Drain engine oil.
5. Disconnect Engine Oil Cooler Lines.
Follow OEM procedure.
6. Air Compressor equipped engines
only: Disconnect Oil Return Line (3) at
Adapter (2). Figure 1
7. Temporarily plug Air Compressor Oil
Return Line and secure out of the way.
8. If replacing a damaged Oil Pan on an
Air Compressor equipped engine only:
Remove Oil Return Line Adapter (2)
from Oil Pan (4). Figure 1
9. Remove twenty (20) Oil Pan Retaining
Bolts (1). Figure 1
10. Remove Oil Pan (4) from vehicle.
11. Remove Oil Pan Gasket and discard.

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1

1
2

3

4

Figure 1:
Oil Pan (4), Oil Pan Retaining Bolts (1),
Air Compressor Oil Return Line (3) and Adapter (2)

488LPI Propane Autogas Engine Mechanical
and Fuel Components Service Manual

Page 85 of 117

INSTALLATION PROCEDURE
1. Inspect Oil Pan to Engine mounting
surfaces.
2. Install new Oil Pan Gasket on Oil Pan.
3. Install Oil Pan (4) on engine. Figure 2
4. Torque Oil Pan Retaining Bolts
following Figure 2 torque sequence.
Refer to Engine Mechanical Torque
and Clearance Specifications.
5. If installing a new Oil Pan on an Air
Compressor equipped engine only:
Apply Teflon tape to the Return Line
Adapter fitting. Install Oil Return Line
Adapter (2) on Oil Pan (4). Figure 2.
Refer to Engine Mechanical Torque
and Clearance Specifications.
6. Air Compressor equipped engines
only: Connect Air Compressor Oil
Return Line (3) to Adapter (2). Figure
1. Refer to Engine Mechanical Torque
and Clearance Specifications.
7. Connect Engine Oil Cooler Lines.
Follow OEM procedure.
8. Install Oil Drain Plug (if not installed).
Refer to Engine Mechanical Torque
and Clearance Specifications.
9. Install Oil Dipstick Tube using lower
Clip and Bolt. Follow OEM procedure.
10. Lower vehicle.
11. Fill engine oil. Refer to 488LPI™
Owner’s Manual for Capacities and
Requirements.
12. Clean any excess oil from engine.
13. Inspect for leaks.
14. Run engine to operating temperature
for twenty (20) minutes.
15. Inspect again for leaks.

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2

Figure 2:
Oil Pan Retaining Bolt Torque Sequence

488LPI Propane Autogas Engine Mechanical
and Fuel Components Service Manual

Page 86 of 117

Oil Pump Drive Replacement
REMOVAL PROCEDURE
1. Remove Upper Intake Manifold. Refer
to Upper Intake Manifold Replacement.
2. Remove Lower Intake Manifold. Refer
to Lower Intake Manifold Replacement.
3. Remove Valley Pan (1). Figure 1
4. Remove Oil Pump Drive Retaining Bolt
(2). Figure 2
5. Slide Oil Pump Drive (3) from Oil Pump
Bore (5) and remove from engine.
Figure 2
6. Clean and inspect Oil Pump Drive (3).
Figure 2

1

INSTALLATION PROCEDURE
1. Apply film of oil to Oil Pump Drive Gear
(6) to ease assembly. Figure 2
2. Align Oil Pump Drive Gear (4) with Oil
Pump Drive Shaft (not shown). Figure
2
IMPORTANT: Oil Pump Drive Gear
must be aligned with the Oil Pump
Drive Shaft turned by the Camshaft
Gear. Align gears by rotating Oil Pump
Drive back and forth until it seats itself.
Do not force drive into position as gear
damage may occur.
3. Install Oil Pump Drive (3) into Oil Pump
Bore (5). Verify Oil Pump Drive (3) is
fully seated in bore. Figure 2
4. Install Oil Pump Drive Retaining Bolt
(2). Refer to Engine Mechanical
Torque and Clearance Specifications.
Figure 2
5. Install Valley Pan (1). Figure 1
6. Install Lower Intake Manifold. Refer to
Lower Intake Manifold Replacement.
7. Install Upper Intake Manifold. Refer to
Upper Intake Manifold Replacement.
8. Fill engine fluids. Follow OEM
procedure and 488LPI™ Owners
Manual Maintenance Specifications.
9. Verify proper operation.

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Figure 1:
Valley Pan (1)
2

4

3

5
Figure 2:
Oil Pump Drive (3), Oil Pump Drive Retaining
Bolt (2), Oil Pump Drive Gear (4),
Oil Pump Bore (5)

488LPI Propane Autogas Engine Mechanical
and Fuel Components Service Manual

Page 87 of 117

Oil Pump Replacement
REMOVAL PROCEDURE
1. Secure vehicle. Verify engine is off and
has had ample cooling time.
2. Drain engine oil.

3.
4.
5.
6.
7.

Collect oil and dispose of properly.
Remove Oil Pan. Refer to Oil Pan
Replacement.
Remove Oil Pump Retaining Bolt (1).
Figure 1.
Remove Oil Pump (2), Oil Pump Shaft
Retainer (3), and Oil Pump Driveshaft
(4). Figure 1
Separate Oil Pump, Oil Pump Shaft
Retainer, and Oil Pump Driveshaft.
Discard Oil Pump Retainer (3).

1
2

INSTALLATION PROCEDURE
1. Assemble new Oil Pump Shaft
Retainer (3) and Oil Pump Driveshaft
(4). Figure 1
2.

3.
4.
5.
6.
7.

Oil Pump Gear must be aligned with
the Oil Pump Drive Shaft turned by
the Camshaft Gear. Align gears by
rotating Oil Pump Driveshaft back
and forth until it seats itself. Do not
force Driveshaft into position as
gear damage may occur.
Install Oil Pump Assembly. Position Oil
Pump (2) on Locating Pins. Figure 1
Install Oil Pump Retaining Bolt (1).
Refer to Engine Mechanical Torque
and Clearance Specifications.
Install Oil Pan. Refer to Oil Pan
Replacement. Figure 1
Fill engine oil. Follow OEM procedure
and 488LPI™ Owners Manual.
Verify proper operation.

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3
4

Figure 1:
Oil Pump (2), Oil Pump Retaining Bolt (1), Oil
Pump Shaft Retainer (3), Oil Pump Driveshaft (4).

488LPI Propane Autogas Engine Mechanical
and Fuel Components Service Manual

Page 88 of 117

Power Steering Pump Pulley Replacement
DESCRIPTION AND OPERATION
The 488LPI™ engine is equipped with a provision for OEM power steering. The Crankshaft Pulley
turns the Power Steering Pump Pulley driven via the Main Accessory Drive Belt.

When replacing the OEM-supplied Power Steering Pump, the Power Steering Pump Pulley
must be transferred from the old Power Steering Pump to the new unit.

In the unlikely event of Power Steering Pump Pulley damage, replace the Pulley to avoid
damage to the Power Steering Pump or Main Accessory Drive Belt.
REMOVAL PROCEDURE
1. Secure vehicle and verify engine is off
and cool.
2. If equipped: Remove Dual Air
Conditioning Compressor Drive Belt.
Refer to Dual Air Conditioning
Compressor Belt Replacement.
3. Remove Main Accessory Drive Belt.
Refer to OEM Main Accessory Drive Belt
Replacement.
4. Remove Power Steering Pump Pulley
Bolt (5) and Washer (not shown). Figure 1
5. Use Special Tool to remove Power
Steering Pump Pulley from Power
Steering Pump (not shown). Figure 2

3

5

6
Figure 1:
Power Steering Pump location (3),
Power Steering Pump Pulley (5), Bolt (6)

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and Fuel Components Service Manual

Page 89 of 117

INSTALLATION PROCEDURE
1. If installing a new Power Steering Pump:
Install Power Steering Pump (not shown)
on Main Front End Accessory Drive
(FEAD) Bracket at location (3). Figure 1.
Follow OEM procedure.
2. Press Power Steering Pump Pulley (5) on
Power Steering Pump (not shown) using
Special Tool. Figures 1 and 2

3.
4.
5.
6.

7.
8.
9.

Verify Pulley Keyway is properly
aligned.
Install Power Steering Pump Pulley
Bolt (6). Figure 1
Torque Power Steering Pump Pulley Bolt
(6). Figure 1. Refer to Front End
Accessory Drive Specifications.
Install Main Accessory Drive Belt. Refer to
OEM service manual for procedure and
routing.
If equipped: Install Dual Air Conditioning
Compressor Drive Belt. Refer to Dual Air
Conditioning Air Compressor Belt
Replacement.
Verify proper operation.
Clean any spilled fluids from engine.
Run engine to operating temperature and
inspect for leaks.

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488LPI Propane Autogas Engine Mechanical
and Fuel Components Service Manual

Figure 2:
Special Tool example

Page 90 of 117

Pushrod Inspection and Replacement
REMOVAL PROCEDURE
1. Secure vehicle.
2. Verify engine is cool.
3. Remove Valve Cover(s). Refer to
Valve Cover Replacement.
4. Remove Roller Rocker Arm(s) for the
Pushrod(s) being serviced. Refer to
Roller Rocker Arm Replacement.
5. Remove Pushrod(s) (1), (2) being
serviced.
If Pushrod(s) being serviced will
be re-used, organize Pushrods
so they can be reinstalled in
same location.

3

Exhaust Pushrods (2) are longer
than Intake Pushrods (1). Organize
Pushrods in order of removal for
proper reassembly.
INSPECTION PROCEDURE
1. Roll Pushrod on flat surface such as
glass to verify Pushrod is straight.
2. Clean Pushrods using brake cleaner
and an appropriately sized brush.
3. Check Oil Galleys in pushrod
passages for restriction.

Figure 1:
Remove Pushrods (1) and (2) from
Pushrod Guides (3)

Replace any bent, internallyobstructed, or otherwise damaged
pushrods.

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and Fuel Components Service Manual

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INSTALLATION PROCEDURE
1. Install Pushrod(s)—Intake (1) and/or
Exhaust (2)—being serviced. Figure 2
2. Install Valve Rockers. Refer to Valve
Rocker Replacement.
3. Adjust valve lash. Refer to Roller
Rocker Valve Lash Adjustment
Procedure.
4. Install Valve Covers. Refer to Valve
Cover Replacement.
5. Start engine.
Do not rev engine!
6. Bring engine up to temperature and
verify proper operation.

Figure 2:
Install shorter Intake Pushrod (1)
and/or longer Exhaust Pushrod (2)

Valvetrain noise be heard upon start
up. This noise will stop when the
system primes itself. If valvetrain
noise persists additional
diagnosis/repair is required.

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and Fuel Components Service Manual

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Roller Rocker Valve Lash Adjustment Procedure
Valve lash adjustment is required whenever the following cylinder head components are replaced.
 roller rocker arms
 cylinder valves
 push rods
 camshaft
 camshaft lifters

PROCEDURE
1. Remove both valve covers. Refer to Valve Cover Replacement procedure.
2. Remove all eight spark plugs to ease crankshaft rotation. Refer to Spark Plug Replacement procedure.
Store spark plugs by cylinder number for reinstallation.
3. Using an allen wrench, loosen all rocker arm retaining nut set screws so that at least one thread shows
above nut surface.
set screw

rocker arm retaining nut

roller rocker arm
4. Use a breaker bar to rotate crankshaft clockwise until compression stroke for cylinder #1 is on top-deadcenter (TDC).
 At TDC, the piston is on the base lobe/no lift on lifters.
5. Tighten cylinder #1 retaining nut on both intake and exhaust rocker arms until there is zero-lash between
pushrods and rocker arms. Using your fingers, rotate pushrod while tightening retaining nut. Stop rotation
when slight resistance is felt.

rocker arm retaining nut

roller rocker arm

 Cylinder #1 rocker arm is now at zero-lash.

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6. Tighten rocker arm retaining nut an additional 3/4-turn to set lifter preload.
7. While holding rocker arm retaining nut using a closed-end wrench, use a torque wrench to tighten each set
screw as follows:
Intake:

Torque set screws to 20 ft-lbs (27.1 Nm).

Exhaust:

Torque set screws to 15 ft-lbs (27.1 Nm).
Use a paint or wax marker to mark the top of each set screw.

 Cylinder #1 complete.
8. Working through the remaining firing-order (8-7-2-6-5-4-3), place each cylinder on TDC of its compression
stroke.

FRONT

Passenger
side

8

7

6

5

4

3

2

1

Driver
side

Firing order

1–8–7–2–6–5–4–3

Repeat Steps 4 through 7 above.
Before reinstalling valve covers, pour clean engine oil on the rocker arms, making sure to coat
rollers and pushrod tips to assure adequate lubrication until oil pump pressurizes lifters to
feed oil up though the pushrods.
10. Reinstall both valve covers. Refer to Valve Cover Replacement procedure.
11. Reinstall all eight spark plugs. Refer to Spark Plug Replacement procedure.