Piston Oil Jet 8-94370579-1 8943705791 For ISUZU NPR66 4HF1 Diesel Engine

The Piston Oil Jet (OEM Numbers: 8-94370579-1 / 8943705791) is a premium-quality, direct replacement engine component designed specifically for ISUZU NPR66 series medium-duty trucks equipped with 4HF1 diesel engines. This precision-engineered oil jet directs a stream of pressurized oil onto the underside of the piston crown for essential cooling and lubrication.

• OE Quality: Manufactured to strict ISUZU dimensional and material specifications for perfect fit and function
• Precision Orifice: Delivers correct oil flow rate and spray pattern for optimal piston cooling
• Durable Steel Construction: Withstands high oil pressure, temperature, and vibration
• Restores Piston Cooling: Eliminates overheating, scuffing, and seizure caused by clogged or damaged jets
• Direct Replacement: Matches OE jet dimensions and mounting configuration
• Long Service Life: Engineered for heavy-duty diesel engine applications
• Essential for Engine Overhaul: Critical component to replace during piston or block service
• Reliable Performance: Ensures proper lubrication and cooling for extended engine life

This piston oil jet is specifically designed for ISUZU medium-duty trucks and commercial vehicles:

• ISUZU NPR66 (Medium-Duty Trucks)
• ISUZU N Series (NK, NP - as applicable)
• ISUZU 4HF1 Engine Specifications:
  • 4-Cylinder, Inline Diesel
  • Displacement: 4.3L
  • Valvetrain: OHV
  • Application: Medium-duty trucks and commercial vehicles

Also compatible with various ISUZU models using the 4HF1 engine with the same piston cooling jet configuration.

Professional engine builder installation recommended:

1. Drain engine oil - Drain oil to prevent spills during component removal
2. Remove the oil pan - Remove the oil pan to access the piston oil jets
3. Locate the oil jets - Identify the piston cooling jets and note their orientation
4. Remove the old oil jet - Carefully remove the old jet from the engine block
5. Clean the mounting area - Remove dirt, debris, and old sealant from the jet bore
6. Inspect oil galleries - Ensure all oil passages are clear and free from sludge
7. Install the new oil jet - Press or thread the new jet into position with correct orientation
8. Torque if applicable - Tighten to manufacturer torque specifications if threaded
9. Check clearance - Ensure the jet does not contact moving parts
10. Reinstall oil pan - Install new oil pan gasket and reinstall pan with proper torque
11. Refill with engine oil - Fill with correct grade and quantity of engine oil
12. Start and check - Start engine; check oil pressure warning light and inspect for leaks

• Material Verification: Confirms steel composition meets ISUZU strength specifications
• Dimensional Inspection: Jet dimensions and mounting points verified within OEM tolerances
• Flow Testing: Sample tested to ensure correct oil flow rate and spray pattern
• Pressure Testing: Sample tested for integrity under operating oil pressure
• Visual Inspection: 100% checked for cracks, burrs, or manufacturing defects
• Packaged Safely: Protected and packaged to prevent damage during transit

• Neutral export packing or customized packaging available
• Carton or wooden case for safe transportation
• Fast delivery for stock items
• Shipping by Express Air or Sea