Engine - 3.2L & 3.5L V6: Other Isuzu Amigo II

DOHC

All valve adjustment must be done on a cold engine. DOHC engines have a tappet fit over valve spring with a shim on top of tappet. The shim is replaceable and available in assorted thicknesses. Shims are available in .0008" (.020 mm) intervals between .0945-.1260" (2.400-3.200 mm) thickness.

To measure clearance, rotate camshaft positioning heel of lobe over tappet. Using feeler gauge, measure valve clearance between adjustment shim and camshaft lobe. Ensure valve clearance is within specification. See VALVE CLEARANCE ADJUSTMENT SPECIFICATION . To adjust clearance, apply engine oil to camshaft lobe and adjustment shim. Using Valve Clearance Adjusting Tool (J-42689), rotate camshaft and push out adjustment shim with flat-blade screwdriver. Measure shim and replace with appropriate thickness adjustment shim to bring clearance within specification.

VALVE CLEARANCE ADJUSTMENT SPECIFICATION

ACCELERATOR CABLE

Loosen lock nut. Pull outer cable while holding throttle valve closed. Temporarily tighten adjusting nut, and screw cap or lock nut. Loosen adjusting nut 3 turns and tighten screw cap or lock nut. Ensure valve lever returns to stopper screw. (Scheme 17)

Scheme 17

FUEL PRESSURE RELEASE

Note. For reassembly reference, label all electrical connectors, vacuum hoses and fuel lines before removal. Also place mating marks on engine hood and other major assemblies before removal.

Turn ignition off. Remove fuel filler cap. Remove fuel pump relay from underhood relay center. Start engine and allow it to stall. After engine stalls, crank engine for an additional 5 seconds. Disconnect negative battery cable. Remove fuel filler cap. Reinstall fuel pump relay.

OIL PAN

Note. On DOHC models, oil pan removal and installation information is not provided.

Cylinder Head

1. Inspect cylinder head for warpage at cylinder block and manifold areas. Resurface cylinder head if warpage exists on head or manifold surfaces. Replace cylinder head if warpage exceeds specification. See «CYLINDER HEAD»(ref-49505-S23511692642001011500000) under ENGINE SPECIFICATIONS.
2. Inspect cylinder head for cracks, especially in area between valve seats and inside exhaust ports. Check head surface for corrosion and porosity. CAUTION: DO NOT weld cylinder head to repair. Replace cylinder head.
3. Ensure cylinder head height is within specification. See «CYLINDER HEAD»(ref-49505-S23511692642001011500000) under ENGINE SPECIFICATIONS.

Valve Springs

Ensure valve spring free length, out-of-square and pressure are within specification. See VALVES & VALVE SPRINGS under ENGINE SPECIFICATIONS. Install valve springs with painted area of valve spring facing downward.

Valve Stem Oil Seals

Carefully install valve stem oil seal using Seal Installer (J-37986) for SOHC and (J-37281) for DOHC.

Valve Guides

1. Check valve stem-to-guide oil clearance. Ensure valve stem diameter is within specification. Replace valve guide if clearance exceeds specification. Manufacturer recommends replacing valve and valve guide as a set. See «CYLINDER HEAD»(ref-49505-S23511692642001011500000) under ENGINE SPECIFICATIONS.
2. To replace valve guide, use hammer and Valve Guide Remover/Installer (J-37985) for SOHC and (J-42899) for DOHC. Working from combustion side of cylinder head, drive valve guide out of top of head. Apply engine oil to outside of NEW valve guide.
3. Using hammer and valve guide remover/installer, drive valve guide into cylinder head from camshaft side. Measure valve guide installed height from top of valve guide to cylinder head surface. Ensure valve guide installed height is within specification. See «CYLINDER HEAD»(ref-49505-S23511692642001011500000) under ENGINE SPECIFICATIONS. Using reamer, ream valve guide to obtain specified valve stem-to-guide oil clearance. See «CYLINDER HEAD»(ref-49505-S23511692642001011500000) under ENGINE SPECIFICATIONS.

Scheme 18

1. To measure valve seat margin, install a NEW valve in cylinder head. Measure valve installed height from spring seat to tip of valve stem. Replace valve seats if not within specification. See «VALVES & VALVE SPRINGS»(ref-49505-S32348079412001011500000) under ENGINE SPECIFICATIONS.
2. Measure valve seat width. (Scheme 18) Cut or replace valve seats to reach required width specification. See «CYLINDER HEAD»(ref-49505-S23511692642001011500000) under ENGINE SPECIFICATIONS.
3. Replace valve seat if damaged. To remove valve seat, arc weld a welding rod to valve seat in several areas to shrink valve seat. Allow valve seat to cool. Gently tap on welding rod to remove valve seat. Ensure valve seat area in cylinder head is clean.
4. To install valve seat, heat valve seat area of cylinder head with steam. Cool valve seat with dry ice or refrigerate. Install valve seat in cylinder head. Valve seat-to-cylinder head interference fit should be.004-.006" (.11-.15 mm). Grind valve seat to specified seat width. See «CYLINDER HEAD»(ref-49505-S23511692642001011500000) under ENGINE SPECIFICATIONS.

Valves

Ensure valve stem diameter is within specification. Replace valves if not within specifications. Manufacturer recommends replacing valve and valve guide as a set. See VALVES & VALVE SPRINGS under ENGINE SPECIFICATIONS.

Valve Seat Correction Angles

After grinding seat, to lower seat, use a 30-degree stone to remove stock from top of valve seat on all valves. To raise seat, use a 75-degree stone to remove stock from bottom of seat on all valves.

Valve Lifters (SOHC)

1. Visually inspect hydraulic valve lifters. Replace parts if damage or abnormal wear is present. If outside diameter is not within specification, replace lifter. See «VALVE LIFTERS»(ref-49505-S39469909072001011500000) under ENGINE SPECIFICATIONS. CAUTION: DO NOT disassemble hydraulic valve lifter. Keep lifter upright and submersed in oil when not being measured.
2. Subtract outside diameter of lifter from inside diameter of lifter mounting in rocker arm (SOHC), or inside diameter of cylinder head (DOHC). On SOHC, replace rocker arm and/or lifter if oil clearance exceeds specification. On DOHC, replace cylinder head and/or lifter if oil clearance exceeds specification. See «VALVE LIFTERS»(ref-49505-S39469909072001011500000) under ENGINE SPECIFICATIONS.

Fitting Pistons

1. Determine if piston-to-cylinder clearance is within specification. See «PISTONS, PINS & RINGS»(ref-49505-S27093090402001011500000) under ENGINE SPECIFICATIONS. Measure piston skirt diameter at a 90-degree angle to piston pin 1.22" (31.0 mm) from top of piston for SOHC and 1.69" (43.0 mm) from top of piston for DOHC. Different piston sizes are used. Piston size can be identified by letter (size mark) stamped on top of piston. (Scheme 19)
2. Size mark on piston is a letter corresponding to piston diameter. Ensure piston diameter is within specification. See «PISTONS, PINS & RINGS»(ref-49505-S27093090402001011500000) under ENGINE SPECIFICATIONS.
3. Check cylinder bore to determine piston-to-cylinder clearance. Clearance should be within specification. See «PISTONS, PIN & RINGS»(ref-49505-S27093090402001011500000) under ENGINE SPECIFICATIONS.

Scheme 19

Piston Pins

1. Measure piston pin outside diameter in 2 directions and 3 places. (Scheme 20) If outside diameter is not within specification at any one place, replace piston pin. See «PISTONS, PINS & RINGS»(ref-49505-S27093090402001011500000) under ENGINE SPECIFICATIONS.
2. Ensure piston pin to connecting rod interference fit is within specification. Measure inside diameter of connecting rod small end. If interference fit is not within specification, replace connecting rod and piston pin. See «PISTONS, PINS & RINGS»(ref-49505-S27093090402001011500000) under ENGINE SPECIFICATIONS.

Scheme 20

Piston Rings

1. Place NEW piston ring into cylinder bore. Using a piston, push ring into smallest part of cylinder bore. Measure ring end gap. If ring end gap is too large, use an oversize ring. If ring end gap is too small, file material from end of ring. See «PISTONS, PINS & RINGS»(ref-49505-S27093090402001011500000) under ENGINE SPECIFICATIONS.
2. Measure clearance between piston ring groove and piston ring. If clearance is not within specification, replace piston. See «PISTONS, PINS & RINGS»(ref-49505-S27093090402001011500000) under ENGINE SPECIFICATIONS. Position piston ring gaps in proper areas. (Scheme 21)

Scheme 21

Rod Bearings

1. Note direction of connecting rod and cap installation. Ensure connecting rod is installed so front mark at center of connecting rod is toward front of engine. see scheme 17
2. Connecting rod big end bore diameter is indicated by an "A", "B" or "C" size mark stamped on one side of connecting rod. see scheme 17 Ensure big end bore diameter is within specification. See «CONNECTING RODS»(ref-49505-S18084073282001011500000) under ENGINE SPECIFICATIONS.
3. Check rod bearing oil clearance using Plastigage. Ensure bearing oil clearance and side play are within specification. See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS and «CONNECTING RODS»(ref-49505-S18084073282001011500000) under ENGINE SPECIFICATIONS.
4. If rod bearing oil clearance is incorrect, it may be possible to obtain correct clearance using selective service rod bearings. Rod bearings are available in 3 standard service sizes, indicated by a color code on bearing. See «ROD BEARING SPECIFICATIONS»(ref-49505-S05696758832001011500000). Coat nut and threads with engine oil before installing. Tighten nuts to specification. See «TORQUE SPECIFICATIONS»(ref-49505-S22979059872001011500000).

ROD BEARING SPECIFICATIONS

Crankshaft & Main Bearings

1. Ensure main bearing caps are numbered for location. Mark bearing cap for reassembly reference. Remove main bearing cap bolts in proper sequence. (Scheme 22)
2. Cylinder block main bearing bore size is indicated by numerical size mark stamped on cylinder block. (Scheme 23) Main bearing journal size is determined by size marks, given in dashes (-), located on crankshaft front counterweight. (Scheme 24)
3. If color code on original bearing cannot be obtained, use size marks on cylinder block and crankshaft to determine proper color-coded main bearing. See appropriate «MAIN BEARING SELECTION»(ref-49505-S36458742382001011500000). MAIN BEARING SELECTION (1997) Cylinder Block Size Mark Crankshaft Size Mark Bearing Color Code 1 1 Or - Green 1 2 Or - - Brown 2 1 Or - Yellow 2 2 Or - - Green 3 1 Or - Pink 3 2 Or - - Yellow MAIN BEARING SELECTION (1998) Cylinder Block Size Mark Crankshaft Size Mark Bearing Color Code 1 1 Or - Brown 1 2 Or - - Blue 2 1 Or - Green 2 2 Or - - Brown 3 1 Or - Yellow 3 2 Or - - Green
4. When installing main bearing caps, ensure reassembly reference mark on cap points toward front of engine. Coat bolt threads with engine oil before installing.
5. Tighten bolts in sequence to specification. (Scheme 25) See «TORQUE SPECIFICATIONS»(ref-49505-S22979059872001011500000). Ensure crankshaft end play is within specification. See «CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS»(ref-49505-S19414535862001011500000) under ENGINE SPECIFICATIONS.

Scheme 22

Scheme 23

Scheme 24

Scheme 25

Thrust Bearing

Install thrust bearing on No. 3 main bearing so grooves are toward crankshaft, away from cylinder block. Replace thrust bearing if crankshaft end play is not within specification. See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS under ENGINE SPECIFICATIONS.

Cylinder Block

1. Using feeler gauge and straightedge, check cylinder block deck surface warpage. If warpage exceeds specification, resurface or replace cylinder block. See «CYLINDER BLOCK»(ref-49505-S04088730622001011500000) under ENGINE SPECIFICATIONS.
2. Check diameter of cylinder bore. Measure cylinder in axial and thrust directions. Different cylinder bore sizes are used and can be identified by size marks on deck surface of cylinder block. (Scheme 26) Cylinder size marks are stamped in relation to cylinder layout.
3. Ensure diameter of cylinder bore is within specification. See «CYLINDER BLOCK»(ref-49505-S04088730622001011500000) under ENGINE SPECIFICATIONS. If diameter of cylinder bore exceeds maximum limit, replace cylinder block.

Scheme 26

Oil Pressure

With engine at normal operating temperature, ensure oil pressure is 57-80 psi (3.9-5.6 kg/cm 2 ) at 3000 RPM.

CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS

CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS

CONNECTING RODS

CONNECTING RODS

PISTONS, PINS & RINGS

PISTONS, PINS & RINGS

CYLINDER BLOCK

VALVES & VALVE SPRINGS

VALVES & VALVE SPRINGS

CYLINDER HEAD

CAMSHAFT

CAMSHAFT

VALVE LIFTERS

VALVE LIFTERS