Automotive Glossary of Terms - M -
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W
Definitions for automotive terms and illustrations from manifold to multi-weight oil.
MANIFOLD: A casting of passages or set of pipes which connect the cylinders to an inlet or outlet source.
MANIFOLD VACUUM: Low pressure in an engine intake manifold formed just below the throttle plates. Manifold vacuum is highest at idle and drops under acceleration.
MASTER CYLINDER: The primary fluid pressurizing device in a hydraulic system. In automotive use, it is found in brake and hydraulic clutch systems and is pedal activated, either directly or, in a power brake system, through the power booster.
McPHERSON STRUT: A suspension component combining a shock absorber and spring in one unit.
MISFIRE: Condition occurring when the fuel mixture in a cylinder fails to ignite, causing the engine to run roughly.
MODULE: Electronic control unit, amplifier or igniter of solid state or integrated design which controls the current flow in the ignition primary circuit based on input from the pick-up coil. When the module opens the primary circuit, high secondary voltage is induced in the coil.
MULTI-WEIGHT OIL: Type of oil that provides adequate lubrication at both high and low temperatures.

