New 8-97349489-0 ISUZU Head Gasket Cylinder For 4HG1 4HG1T
1. Quick Notice
Confirm your original gasket part number before ordering. This gasket 8-97349489-0 fits Isuzu 4HK1 diesel engines, not 4HG1/4HG1T. Verify bore diameter and piston protrusion grade. Professional installation required. Replace head bolts with new units.
2. Description
The 8-97349489-0 is an OE-spec Multi-Layer Steel (MLS) cylinder head gasket for Isuzu 4HK1 engines. The 4HK1 is a 5.2L inline four-cylinder turbo diesel engine with 115mm bore, 125mm stroke, and compression ratio from 16.5:1 to 18.5:1 depending on model year. Engine output ranges from 155 hp to 240 hp. MLS construction uses multiple stainless steel layers with embossed sealing beads to withstand extreme combustion pressure. Fits Isuzu NPR, NQR, NRR, N-Series trucks, Hitachi excavators (ZX200-3, ZX330), and industrial equipment. Common failure symptoms: external coolant seepage at the head joint, persistent engine overheating, white exhaust smoke, milky oil (coolant-oil mixing), compression loss, and exhaust bubbles in radiator.
3. Parameters Table
| Parameter | Specification |
|---|---|
| OEM Number | 8-97349489-0 |
| Engine Fitment | Isuzu 4HK1, 4HK1-TC, 4HK1X |
| Displacement | 5,193 cc / 5.2L |
| Bore × Stroke | 115 mm × 125 mm |
| Compression Ratio | 16.5:1 / 17.5:1 / 18.5:1 |
| Material | Multi-Layer Steel (MLS) |
| Thickness Grades | 3 grades (select by piston protrusion) |
| Vehicle Fitment | Isuzu NPR, NQR, NRR, N-Series |
| Included | Gasket only |
4. Custom Content
Thickness Selection: Isuzu offers 3 different head gasket thicknesses. Measure piston protrusion above the block deck and select by the smallest measurement. The correct thickness is identified by punch marks on the gasket tab.
Cylinder Head Bolt Torque: M14 bolts — Step 1: 98 Nm (72 ft-lb), Step 2: 147 Nm (108 ft-lb), Step 3: +30–60° angle torque. Always replace head bolts with new torque-to-yield units.
Surface Preparation: Clean both cylinder head and block with a plastic scraper. No abrasive discs or wire brushes. Check cylinder head flatness — maximum 0.10mm distortion.
No Sealant: Install MLS gasket dry on clean surfaces. Do not use any gasket sealant.
5. FAQ (One by One Question and Answer)
Q1: Is 8-97349489-0 for 4HG1 or 4HK1 engine?
A1: This gasket is for Isuzu 4HK1 5.2L engine. For 4HG1/4HG1T engines, use part number 8-97144986-0.
Q2: Which trucks use the 4HK1 engine with this gasket?
A2: Isuzu NPR, NPR-HD, NQR, NRR, and N-Series trucks (2005–2020+ model years).
Q3: What are common head gasket failure symptoms on a 4HK1?
A3: Persistent overheating, white exhaust smoke, milky oil (coolant-oil mixing), coolant loss without external leaks, and exhaust bubbles in radiator.
Q4: Does this gasket require sealant during installation?
A4: No. MLS head gaskets seal without additional sealant. Install dry on clean, properly prepared surfaces.
Q5: What thickness gasket do I need?
A5: Measure piston protrusion above block deck. Select the gasket thickness based on the smallest measurement across all cylinders. Refer to Isuzu workshop manual.
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