Ford Mustang (1999-2004) Service Manual: Intake Air Distribution and Filtering - Supercharger, Charge Air Cooler

The supercharger (SC) is a positive displacement pump. Its purpose is to supply an excess volume of intake air to the engine by increasing air pressure and density in the intake manifold. The supercharger is matched to the engine by its displacement and belt ratio, and can provide excess airflow at any engine speed.

NOTE: The supercharger is repaired only as an assembly. Disassembly of the supercharger unit may void the warranty.

NOTE: The supercharger is not a bolt-on option. It is part of an integrated engine system. Many components of the supercharged engine are not interchangeable with similar parts from a nonsupercharged engine.

The supercharger contains two three-lobed rotors. The helical shape and specialized porting provide a smooth discharge flow and low level of noise during operation. The rotors are supported by ball bearings in front and needle bearings at the rear. The drive gears are pressed into place, therefore the supercharger is installed new as a unit, and is not repairable.

The supercharger system is a blow-through type with the fuel injected directly into the intake ports. The supercharger is belt driven off the crankshaft through an idler pulley. The throttle body controls the amount of intake air to the supercharger through the intake plenum. Air from the supercharger is routed through the charge air cooler (CAC), then to the intake manifold. The resulting denser air charge in the combustion chamber provides for a higher power output of the engine over a nonsupercharged engine of the same displacement.

NOTE: It is not possible to increase manifold pressure or engine power output by altering the bypass valve or the actuator.

At partial-throttle opening or when vacuum is present in the intake system, a vacuum-controlled bypass valve reroutes some discharged air from the supercharger back through the intake plenum.

This prevents the supercharger from cavitating, causing reduced performance, increased temperatures, and poor fuel economy.

The supercharger has a self-contained oiling system that does not require a fluid change for the life of the vehicle. However, at every 30,000 mile interval, the supercharger fluid level should be checked.

The vehicle should be parked on a level surface, the engine cool, and not running. To check the oil, remove the Allen head plug located at the front of the supercharger. The oil level should be at the bottom of the fill plug threads when cold. If the fluid level is low, add Synthetic Supercharger Fluid E9SZ-19577-A or equivalent meeting Ford specification ESE-M99C115-A Supercharged vehicles are equipped with a charge air cooler (CAC). The CAC cools the pressurized air from the supercharger, increasing the air density, which improves combustion efficiency, engine horsepower and torque.

Intake Air Distribution and Filtering

Refer to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.