The Honda 12251-ZG4-003 Cylinder Head Gasket (1.1) is a genuine OEM replacement designed for the GD320 horizontal shaft diesel engine. As a direct Honda OEM component, this gasket is manufactured to the exact specifications required by the GD320 — ensuring correct clamping load and a reliable seal between the cylinder head and the engine block. Confirm your engine's serial number against the fitment table before ordering, as Honda supersedes parts at serial breaks and this variant is designated by its 1.1 thickness specification.
Key Features
- Correct Head-Sealing Specification — the (1.1) designation identifies this as the specific thickness variant required for proper head-to-block clamping on the GD320; selecting the wrong variant risks combustion gas leakage and coolant or oil contamination
- Genuine Honda OEM Quality — sourced directly from Honda, this gasket meets the combustion pressure and thermal cycling demands of the GD320 diesel engine, where precision sealing is critical to long-term compression integrity
- GD320 Diesel Fitment — built specifically for the GD320 horizontal shaft diesel engine; always verify part number 12251-ZG4-003 against your engine's serial number using the fitment table to confirm this is the correct variant for your unit
- Compression and Leak Protection — a failed or worn cylinder head gasket allows combustion gases to escape, leading to power loss, overheating, and potential contamination of the engine's oil supply; replacing it promptly restores the integrity of the combustion chamber
The cylinder head gasket forms a critical seal between the cylinder head and the engine block, containing combustion pressure and preventing the migration of oil, coolant, or diesel combustion gases between the engine's internal passages. On a diesel engine like the GD320, this seal must withstand significantly higher compression pressures than a petrol engine, making gasket condition and correct specification especially important. When the cylinder head gasket fails, common symptoms include loss of compression, white or blue exhaust smoke, overheating, and oil contamination — all of which demand immediate attention to prevent further engine damage.
Part Details
| Part Number | 12251-ZG4-003 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | Cylinder Head Gasket (1.1) |
Compatibility & Fitment
| Name | Models | Serial Range |
|---|---|---|
| Horizontal Shaft Diesel Engine | GD320 | All |
Verify Before You Order
Fitment is machine-number and revision-specific; always confirm your model and serial number against the fitment list.
Why Buy From DHS Equipment
Every part is verified against the manufacturer's part number before it ships, so what you order is what arrives. We carry parts from leading OEM brands and our own DHS Quality Parts line of professional aftermarket components. Need help finding the right part? Our team is available to confirm compatibility whenever you need it. Orders are processed fast to keep your jobs on track. We don't just sell parts. We keep you jobsite ready.
Questions? Contact our team at [email protected] or 866-611-9369 — DHS Equipment is here to help you maintain peak performance.
