Head Gasket – Fits Yanmar 3GM, 3GMD, 3GMF Marine Engines (Replaces 128370-01332/128370-01331)
Head Gasket – Fits Yanmar 3GM, 3GMD, 3GMF Marine Engines (Replaces 128370-01332/128370-01331) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Free standard shipping on all orders under 1 KG
Head Gasket – Fits Yanmar 3GM, 3GMD, 3GMF Marine Engines (Replaces ...
Product Details
This high-quality aftermarket Head Gasket – Fits Yanmar 3GM, 3GMD, 3GMF Marine Engines is designed for reliable sealing between the cylinder head and engine block. It is specifically engineered for Yanmar's 3-cylinder 3GM series marine diesel engines, including the 3GM, 3GMD, and 3GMF models. Please note, this part is not compatible with 3GM30 engines.
It serves as a direct replacement for Yanmar OEM part numbers 128370-01332 and 128370-01331.
- Installation: Engine Service Part
- Application: Seals diesel engine cylinder head to block
- Quality: Precision-engineered to OEM specifications
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Notes |
|---|---|---|
| Yanmar | 128370-01332 | Interchangeable with 128370-01331 |
| Yanmar | 128370-01331 | Superseded by 128370-01332 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This gasket is designed for the following Yanmar marine engines.
| Brand | Model | Stroke | OEM Part No. | Notes |
|---|---|---|---|---|
| Yanmar | 3GM | 4-Stroke | 128370-01332 / 128370-01331 | Not compatible with 3GM30 models |
| Yanmar | 3GMD | 4-Stroke | 128370-01332 / 128370-01331 | Not compatible with 3GM30 models |
| Yanmar | 3GMF | 4-Stroke | 128370-01332 / 128370-01331 | Not compatible with 3GM30 models |
Technical Specs
- Product Type
- Cylinder Head Gasket
- Installation
- Engine Service Part
- Fuel Type
- Diesel
- Material
- Aftermarket OEM-Specification
- Dimensions
- 31.5 cm L x 18.5 cm W x 0.4 cm H
- Weight
- 0.2 kg (0.44 lb)
- Application
- Seals between cylinder head and engine block
- Compatibility
- Yanmar 3GM, 3GMD, 3GMF Marine Engines
- OEM Quality
- Precision-engineered to OEM specifications
What’s in the Box
- 1 x Head Gasket (Replaces 128370-01332/128370-01331)
Installation Notes
- Safety First: Disconnect the battery and ensure the engine is cool before starting work.
- Drain Fluids: Drain the engine coolant completely into a suitable container.
- Disassembly: Carefully remove intake/exhaust manifolds and any other components obstructing the cylinder head. Loosen and remove the cylinder head bolts in the reverse order of the torque sequence specified in your service manual.
- Remove Head: Lift the cylinder head off the engine block. Do not pry between the mating surfaces.
- Clean Surfaces: Thoroughly clean the surfaces of both the cylinder head and the engine block. Remove all old gasket material and carbon deposits. Ensure surfaces are perfectly clean, dry, and flat.
- Position Gasket: Place the new head gasket onto the engine block, ensuring it is correctly oriented according to the guide dowels. Do not use sealant unless explicitly required by the manufacturer.
- Reinstall Head: Carefully lower the cylinder head back onto the block over the new gasket.
- Torque Bolts: Install clean head bolts. Tighten them in the correct sequence and torque stages as specified in your engine's service manual. This is critical for a proper seal.
- Reassemble: Reinstall all other components in the reverse order of removal.
- Refill & Check: Refill the cooling system. Reconnect the battery. Start the engine and carefully check for any coolant, oil, or exhaust leaks.
Troubleshooting & FAQ
How do I confirm this gasket fits my Yanmar engine?
This head gasket is specifically for Yanmar 3GM, 3GMD, and 3GMF marine engines. It is essential to verify your engine model. This part is NOT compatible with the Yanmar 3GM30 series, which requires a different gasket.
What are the signs of a failed head gasket?
Common symptoms include engine overheating, loss of power, white smoke from the exhaust (indicating coolant burning), milky or foamy engine oil, or bubbles in the coolant overflow tank. These signs suggest a breach in the seal between the cylinder head and block.
Is there a difference between part numbers 128370-01332 and 128370-01331?
No, both part numbers refer to the same component. 128370-01332 is the later or superseding number for 128370-01331. They are fully interchangeable for the specified engine models.
Do I need to use sealant with this head gasket?
Generally, modern head gaskets are designed to be installed dry without any additional sealant. Applying sealant can interfere with the seal and cause premature failure. Always follow the specific instructions in your engine's official service manual.
Can I reuse my old head gasket?
No. Head gaskets are single-use components. They are designed to compress and 'crush' to create a perfect seal. Once removed, a gasket will not provide a reliable seal if reinstalled and will likely cause leaks.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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