# 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-   3594800 earlier number superseded by this part
-   21404010 earlier number superseded by this part
-   3889766 earlier number superseded by this part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

## Details

- **Price:** 5711.49 AUD
- **Vendor:** Volvo Penta
- **Type:** Oil & Lubrication
- **Tags:** Volvo Penta

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 5711.49 AUD | In stock |

## Images

- 21403974 Oil Cooler | Genuine Volvo Penta Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/21403974-oil-cooler-genuine-volvo-penta)
> Updated: 2026-10-11