MLS Head Gasket – OEM ref 11044EY05A

Why this part is needed

This precision head gasket seals the combustion chambers and separates oil and coolant passages. It keeps compression strong, prevents oil/coolant mixing, and stops external leaks. If you want stable power, clean emissions, and long engine life, a fresh, correctly spec’d gasket is essential.

How it works

Built as a multi‑layer steel (MLS) stack with elastomer coating, it conforms to block and head surfaces under clamp load. A reinforced fire ring surrounds each cylinder to hold back extreme pressure and heat. Micro‑beads around oil and coolant ports control crush for a uniform seal. When torqued in sequence, it maintains sealing even through heat cycles and vibration.

What happens if it fails ️

Symptoms include overheating, white exhaust smoke, rough idle, misfire, loss of power, and coolant loss with no visible leak. Oil may look milky, or you may see bubbles in the expansion tank. Driving like this can warp the head, foul plugs, damage the catalytic converter, and lead to full engine rebuild.

Tech notes for best results

• Check deck/head flatness and surface finish (RA) before install.
• Use new torque‑to‑yield bolts if specified; follow factory torque/angle sequence.
• Clean threads, verify dowels in place, install dry unless OEM says otherwise.

Compatibility

• Q70/M
• Qx50/Ex
• Q60/G Coupe
• Q50
• M
• Q40/G Sedan
• Q60/G Convertible
• Qx70/Fx
• G37 Sedan