21389857 Piston Cooling Jet | Genuine Volvo Penta Part

🔧 Product Description

Engine lubrication-system oil spray nozzle used on Volvo Penta D9A2A engines. Six jets are fitted per engine, with each nozzle directing pressurised engine oil toward the underside of a piston crown to control piston temperature and provide additional lubrication under sustained load.

🚤 Compatibility

Typically suits:

• Volvo Penta D11C1-A MP
• Volvo Penta D11C3-A MP
• Volvo Penta D11C2-A MP
• Volvo Penta D11C4-A MP
• Volvo Penta D11B3-A MP
• Volvo Penta D11B4-A MP
• Volvo Penta D11A-C
• Volvo Penta D11A-E
• Volvo Penta D11B2-A MP
• Volvo Penta D11A-C MP
• Volvo Penta D11A-D MP
• Volvo Penta D11A-E MP
• Volvo Penta D11A-C (IPS)
• Volvo Penta D11B1-A MP
• Volvo Penta D9A2D
• Volvo Penta D9A2B
• Volvo Penta D9A2F
• Volvo Penta D9A2A
• Volvo Penta D9A2C
• Volvo Penta D9A2E

• Engine Family: D

⚙️ Key Features

• Genuine Volvo Penta piston-cooling oil jet
• Directs lubricating oil to the underside of the piston crown
• Six jets required for a complete D9A2A engine set
• Precision oilway and nozzle geometry for correct spray targeting
• Essential protection component during engine overhaul or piston damage repair
• Engine type: Volvo Penta D9 inline six-cylinder marine diesel
• 6 used per assembly

🔌 Function

Meters and aims a controlled stream of pressurised oil at the underside of each piston. This removes heat from the piston crown and supports lubrication of the piston, pin and cylinder area during high-load operation.

⚠️ Common Signs of Failure

• Elevated piston-crown temperature or localised overheating damage
• Piston scuffing, seizure marks or accelerated cylinder wear
• Carbon or sludge blockage in the jet or oil feed
• Low oil pressure if a jet or its mounting is broken or leaking
• Repeat piston damage after overhaul when a damaged jet is not replaced

🛠️ Service Notes

• Check the nozzle bore and the oil feed passage in the block are clear before fitting — gasket residue, sealant and carbon block these jets and a blocked jet lets piston temperature run away
• Handle the jet carefully and do not bend, straighten or reshape the nozzle tube to make it fit; a bent or cracked nozzle sprays in the wrong place and must be replaced, not corrected
• Fit the jet square on its locating dowel or spigot so it sits in the position the workshop manual for your engine shows, and tighten to the figure given there
• With the jet in place, bar the engine over by hand and check the nozzle clears the piston skirt and connecting rod through the full stroke
• Renew jets whenever pistons or liners are disturbed and the engine has run dirty or with extended oil changes, and confirm oil is delivered at each jet before the engine is loaded

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 21389857 → Supersedes 3889547

OEM / Related Numbers

• 3889547 earlier number superseded by this part
• 966378 - associated retaining flange screw; not a jet substitute
• 21736639 - associated oil-pump reference within the lubrication system; not a substitute

📦 Condition

• Genuine Volvo Penta part
• Brand new
• Supplied in original or equivalent packaging