Michael GrayenWhy does my car have a plastic intake manifold?
An intake manifold is an integrated assembly that sits atop the engine, consisting of a series of tubes which distribute fresh outside air to each and every cylinder. On V-shaped engine blocks, an intake manifold typically sits between the two cylinder banks while inline engines may feature a manifold to the side of the cylinder head. Intake manifolds serve as a mounting point for carburetors, throttle body assemblies, fuel injectors, thermostats, and more depending on vehicle manufacturer engineering preferences. Intake manifolds may also serve to route coolant through dedicated channels in order to remove heat from the engine. Because of their location and functionality, intake manifold assemblies are under constant stress from engine vacuum pressure as well as direct heat from coolant, cylinder combustion gasses, and the cylinder heads to which they are mounted.