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 table. 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 In. (mm) |
|---|---|
| Exhaust | .010-.014 (.25-.35) |
| Intake | .009-.013 (.23-.33) |
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 8)
Scheme 8
FUEL PRESSURE RELEASE
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. Reinstall fuel filler cap. Reinstall fuel pump relay.
TIMING BELT
Note. See TSB IB00-S005: 3.5L V6 DOHC (6VE1)/3.2L V6 DOHC (6VD1) ENGINES TIMING BELT INSTALLATION for Isuzu. See TSB 02-047: CYLINDER HEAD SERVICE for Honda.
For timing belt removal and installation, for Honda, see TIMING BELT REPLACEMENT - 3.2L - DOHC , for Isuzu, see TIMING BELT REPLACEMENT - 2.2L - DOHC .
OIL PAN
Note. Oil pan removal and installation information is not provided.
Cylinder Head
- 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-8464-S14659345712000083100000) table under ENGINE SPECIFICATIONS.
- 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.
- Ensure cylinder head height is within specification. See «CYLINDER HEAD»(ref-8464-S14659345712000083100000) table under ENGINE SPECIFICATIONS.
Valve Springs
Ensure valve spring free length, out-of-square and pressure are within specification. See VALVES & VALVE SPRINGS table under ENGINE SPECIFICATIONS. Install valve springs with painted area of valve spring facing downward.
| CAUTION | Ensure valve spring is installed with painted area toward cylinder head surface. |
Valve Stem Oil Seals
Carefully install valve stem oil seal using Seal Installer (J-37281).
Valve Guides
- 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-8464-S14659345712000083100000) table under ENGINE SPECIFICATIONS.
- To replace valve guide, use hammer and Valve Guide Remover/Installer (J-42899). Working from combustion side of cylinder head, drive valve guide out of top of head. Apply engine oil to outside of NEW valve guide.
- 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-8464-S14659345712000083100000) table under ENGINE SPECIFICATIONS. Using reamer, ream valve guide to obtain specified valve stem-to-guide oil clearance. See «CYLINDER HEAD»(ref-8464-S14659345712000083100000) table under ENGINE SPECIFICATIONS.
Scheme 9
- 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-8464-S36170144132000083100000) table under ENGINE SPECIFICATIONS.
- Measure valve seat width. (Scheme 9) Cut or replace valve seats to reach required width specification. See «CYLINDER HEAD»(ref-8464-S14659345712000083100000) table under ENGINE SPECIFICATIONS.
- 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.
- 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-8464-S14659345712000083100000) table 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 table 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.
Fitting Pistons
- Determine if piston-to-cylinder clearance is within specification. See «PISTONS, PINS & RINGS»(ref-8464-S17293426552000083100000) table under ENGINE SPECIFICATIONS. Measure piston skirt diameter at a 90-degree angle to piston pin 1.69" (43.0 mm) from top of piston. Different piston sizes are used. Piston size can be identified by letter (size mark) stamped on top of piston. (Scheme 10)
- Size mark on piston is a letter corresponding to piston diameter. Ensure piston diameter is within specification. See «PISTONS, PINS & RINGS»(ref-8464-S17293426552000083100000) table under ENGINE SPECIFICATIONS.
- Check cylinder bore to determine piston-to-cylinder clearance. Clearance should be within specification. See «PISTONS, PIN & RINGS»(ref-8464-S17293426552000083100000) table under ENGINE SPECIFICATIONS.
Scheme 10
Piston Pins
- Measure piston pin outside diameter in 2 directions and 3 places. (Scheme 11) If outside diameter is not within specification at any one place, replace piston pin. See «PISTONS, PINS & RINGS»(ref-8464-S17293426552000083100000) table under ENGINE SPECIFICATIONS.
- 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-8464-S17293426552000083100000) table under ENGINE SPECIFICATIONS.
Scheme 11
Piston Rings
- 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-8464-S17293426552000083100000) table under ENGINE SPECIFICATIONS.
- Measure clearance between piston ring groove and piston ring. If clearance is not within specification, replace piston. See «PISTONS, PINS & RINGS»(ref-8464-S17293426552000083100000) table under ENGINE SPECIFICATIONS. Position piston ring gaps in proper areas. (Scheme 12)
Scheme 12
Rod Bearings
- 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 5
- 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 5 Ensure big end bore diameter is within specification. See «CONNECTING RODS»(ref-8464-S24719747932000083100000) table under ENGINE SPECIFICATIONS.
- Check rod bearing oil clearance using Plastigage. Ensure bearing oil clearance and side play are within specification. See «CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS»(ref-8464-S02440142342000083100000) and «CONNECTING RODS»(ref-8464-S24719747932000083100000) tables under ENGINE SPECIFICATIONS.
- 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-8464-S20509722672000083100000) table. Coat nut and threads with engine oil before installing. Tighten nuts to specification. See «TORQUE SPECIFICATIONS»(ref-8464-S37500002532000083100000).
| Color Code | Bearing Thickness - In. (mm) |
|---|---|
| Yellow | .0595-.0597 (1.512-1.516) |
| Green | .0594-.0595 (1.508-1.512) |
| Pink | .0592-.0594 (1.504-1.508) |
ROD BEARING SPECIFICATIONS
Crankshaft & Main Bearings
- Ensure main bearing caps are numbered for location. Mark bearing cap for reassembly reference. Remove main bearing cap bolts in proper sequence. (Scheme 13)
- Cylinder block main bearing bore size is indicated by numerical size mark stamped on cylinder block. (Scheme 14) Main bearing journal size is determined by size marks, given in dashes (-), located on crankshaft front counterweight. (Scheme 15)
- 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 «MAIN BEARING SELECTION»(ref-8464-S09425045292000083100000) table.
- When installing main bearing caps, ensure reassembly reference mark on cap points toward front of engine. Coat bolt threads with engine oil before installing.
- Tighten bolts in sequence to specification. see scheme 16 See «TORQUE SPECIFICATIONS»(ref-8464-S37500002532000083100000). Ensure crankshaft end play is within specification. See «CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS»(ref-8464-S02440142342000083100000) table under ENGINE SPECIFICATIONS.
| 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 |
MAIN BEARING SELECTION
Scheme 13
Scheme 14
Scheme 15
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 table under ENGINE SPECIFICATIONS.
Cylinder Block
- Using feeler gauge and straightedge, check cylinder block deck surface warpage. If warpage exceeds specification, resurface or replace cylinder block. See «CYLINDER BLOCK»(ref-8464-S32734874852000083100000) table under ENGINE SPECIFICATIONS.
- 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 16) Cylinder size marks are stamped in relation to cylinder layout.
- Ensure diameter of cylinder bore is within specification. See «CYLINDER BLOCK»(ref-8464-S32734874852000083100000) table under ENGINE SPECIFICATIONS. If diameter of cylinder bore exceeds maximum limit, replace cylinder block.
Scheme 16
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.