Mercedes-Benz cylinder head assembly OM612 908578 17MBOM312B

The Toyota 1KZ short valve cylinder head assembly 171522 fits engines that run into common top-end issues—cracked castings, uneven sealing, or compression drop after heavy use. Most mechanics who work on the 1KZ know how sensitive this engine gets once the head heats up too often. This replacement sits into the block without fuss and lines up with the original bolt pattern and coolant passages.

The valves come pre-fitted, so the head goes on quicker during a rebuild. In most cases, this saves time during setup, especially when the shop has a long queue of diesel repairs. Another thing worth noting: the ports match the 1KZ layout, so airflow stays close to stock and the engine breathes the way it should once everything is torqued down.

Why buyers choose this head

• Fits Toyota 1KZ engines without modification
• Valves come seated, which shortens installation time
• Helps solve overheating damage, warping, and sealing issues
• Supports smoother idling and better compression recovery
• Useful for workshops, fleet servicing, and direct replacements

Some engines come in with deep cracks near the injector seats, while others show uneven surfaces that no longer hold a proper gasket. This assembly works as a fresh starting point. Once installed with the correct torque pattern and a clean gasket surface, the engine settles back into steady performance.

Acme Impex inspects each casting for fit and uniformity before dispatch. Our goal is simple: supply a cylinder head that fits right, supports dependable running, and keeps the repair moving without delays.

If you want a straightforward replacement that helps bring a 1KZ diesel back to working condition, this head is a practical choice.