Mahle HS54991 Engine Cylinder Head Gasket Set

Mahle HS54991 Cylinder Head Gasket Set

The Mahle HS54991 engine cylinder head gasket set is built for OE-standard sealing performance in repair jobs that demand precise fit and dependable sealing. It is a strong choice for Mazda CX-9, Mazda 6, Lincoln MKS, and Lincoln MKT applications where multiple engine sealing points need to be addressed during service.

Mahle gaskets are trusted by OEMs and technicians worldwide for consistent sealing quality. This set includes a broad range of related seals and gaskets for the cylinder head, intake, exhaust, valve cover, timing cover, cooling passages, and fuel system interfaces.

Key Features

• OE Standard engine cylinder head gasket set
• Mahle HS54991 for multi-point engine resealing
• Includes cylinder head gaskets, intake manifold gaskets, exhaust manifold gaskets, valve cover gaskets, and more
• Contains seals and O-rings for camshaft VCT solenoids, injectors, thermostat housing, coolant inlet pipe, and timing components
• Includes RTV for sealing applications where specified by the service procedure
• Cross-reference: FEL-PRO HS 26543 PT-1

Detailed Description

The Mahle HS54991 is an OEM-standard gasket set engineered for comprehensive top-end engine service. It brings together the sealing components commonly replaced during cylinder head work, including head gaskets, intake and exhaust manifold gaskets, valve cover gaskets, spark plug tube seals, valve stem seals, timing cover seal, and multiple O-rings for coolant, fuel, and valve timing interfaces. For Mazda CX-9 and Mazda 6 repairs, as well as Lincoln MKS and Lincoln MKT applications, this part number supports a thorough reseal of the engine’s critical sealing surfaces. The Mahle HS54991 is a practical choice when the goal is to restore sealing integrity across the engine assembly with one matched gasket set.

Vehicle Fitment

• Fits 2008-2015 Mazda CX-9, N/A. Cylinder head bolts not included; replacement recommended.
• Fits 2009-2013 Mazda 6, N/A. Cylinder head bolts not included; replacement recommended.
• Fits 2009-2010 Lincoln MKS, N/A. Cylinder head bolts not included; replacement recommended.
• Fits 2010 Lincoln MKT, N/A. Cylinder head bolts not included; replacement recommended.

Common Repair Uses

• Head gasket replacement after overheating or combustion sealing failure
• Resealing intake and exhaust manifold interfaces during engine teardown
• Repairing oil or coolant leaks from valve cover, thermostat, or crossover sealing points
• Addressing vacuum, fuel, or air leaks at injector, throttle body, and O-ring locations
• Restoring sealing performance during timing cover or top-end engine service

Installation Notes

Follow the factory service procedure for surface preparation, torque sequence, and torque-angle specifications. Cylinder head bolts are not included with this set, and replacement is recommended during installation. Inspect the head and block for warpage, clean all mating surfaces carefully, and replace any worn fasteners or damaged components before reassembly.

Quality Assurance

Mahle supplies sealing products used by OEMs and professional technicians, and this gasket set is built to OE-standard expectations for fit and sealing performance.