21403974 Oil Cooler | Genuine Volvo Penta Part

🔧 Product Description

Genuine oil-to-coolant heat exchanger used on Volvo Penta D13B and D13C marine propulsion and generator engines. The cooler transfers heat from pressurised engine oil into the closed-circuit coolant system to maintain oil viscosity and protect bearings, pistons and turbocharger components.

🚤 Compatibility

• Engine Family: D

Full model list at the end of this description.

⚙️ Key Features

• D13B and D13C engine-oil heat exchanger
• 5.33 kg
• Marine propulsion and genset application
• Factory oil and coolant passage geometry
• Designed for 12.8-litre high-output diesel engines
• Uses dedicated O-rings, plates and mounting hardware
• Related earlier or alternative cooler 3594800 requires serial confirmation

🔌 Function

The cooler removes excess heat from engine oil so the lubrication system maintains the viscosity and film strength required under continuous high load.

⚠️ Common Signs of Failure

• High engine-oil temperature
• Oil found in the coolant or coolant found in the engine oil
• External oil or coolant leakage
• Low oil pressure after the engine warms
• Bearing or turbocharger wear caused by overheated oil

🛠️ Service Notes

• Oil cooler 20742946 at 5.729 kg carries an overlapping D13B and D13C listing, so confirm the part number and engine serial before ordering either

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 21403974 → Supersedes 21404010 → Supersedes 3889766

OEM / Related Numbers

• 3594800 earlier number superseded by this part
• 21404010 earlier number superseded by this part
• 3889766 earlier number superseded by this part
• 925064 - O-ring
• 984734 - Flange screws
• 984755 - Flange screws
• 994010 - Nipple
• 21242898 - Cooling-plate references
• 21242895 - Cooling-plate references
• 21242894 - Cooling-plate references
• 925255 - O-rings
• 994661 - O-rings
• 21111085 - Bottom-plate references
• 21446285 - Bottom-plate references

📦 Condition

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

🔎 Full Model Compatibility

Typically suits:

• Volvo Penta D13C3-B MH, D13C1-B MH, D13C2-B MP, D13C1-A MP, D13C2-A MP, D13C3-A MP, D13C4-A MP, D13B-A MP, D13B-H MP, D13B-G MP, D13B-L MP, D13B-E MG, D13B-E MG (FE), D13B-E MH, D13B-E MH (FE), D13B-F MG, D13B-F MG (FE), D13B-K MP, D13B-N MH, D13B-N MH (FE), D13B-B MP, D13B-D MP, D13B-J MP, D13B-M MP, D13B-C MP, D13C4-B MP, D13C5-B MP, D13C6-A MP, D13C1-A MH, D13C5-A MP, D13C1-A MG, D13C7-B MP, D13C8-B MP