Engine Description: Notes

The 7.3L diesel engine is:

• A four-cycle turbocharged V8 with overhead valves.
• 7.3 liter (444 cubic inch) displacement.
• Separated into two banks, the right bank numbered 1, 3, 5, 7 and the left bank numbered 2, 4, 6, 8.
• Rated at 215 horsepower at 3000 rpm.

The cylinder block (6010) has been designed to withstand the loads of diesel operations by using:

• Four-bolt main bearing caps.
• Internal piston cooling oil jets (6C327).
• A forged steel crankshaft (6303).
• Heavy-duty forged steel connecting rods (6200).

The piston is:

• Made of aluminum alloy.
• Fitted with an upper keystone compression ring.
• Fitted with a lower rectangular compression ring.
• Fitted with oil control rings.

The piston pins (6135) are:

• A free-floating type permitting the piston pin to move/float freely in the piston pin bore.
• Retained in the piston and rings by piston pin retainers (6140).

The camshaft (6250) is:

• Supported by five insert-type camshaft bearings (6A251).
• Driven by the crankshaft through the use of the crankshaft gear and the camshaft gear.

The hydraulic valve tappets (6500):

• Minimize engine noise.
• Maintain zero valve lash.
• Incorporate camshaft follower guides.
• Incorporate a roller follower design that reduces camshaft wear.

The cylinder heads (6049) are designed:

• To incorporate electronically controlled/hydraulically actuated fuel injectors (9F593).
• To locate the fuel injectors in the center of the combustion chambers between the rocker arms (6564).
• With integral high-pressure oil galleries.

The glow plug system is:

• Designed to preheat the cylinders for faster cold weather starts.
• Controlled by the powertrain control module (PCM) (12A650).
• Mounted directly into the cylinder heads.
• Activated by the glow plug control module (12B533).

The manifold intake air heater:

• Is designed to preheat intake air to reduce smoke and odor during cold weather starts.
• Is controlled by the powertrain control module (PCM).
• Is mounted into the compressor manifold to heat intake air.

The optional block heater (6A051) is:

• Designed to heat the engine coolant and oil for improved cold weather starts.
• Located near the oil filter (6731) in the oil cooler (6A642).
• Powered by a 120-volt external power source.
• Not repairable; a new block heater must be installed.

The fuel injection system used on the engine:

• Is controlled by the powertrain control module.
• Utilizes an electric in-line fuel pump (9350).
• Circulates through a combination fuel filter, fuel heater and water separator assembly.
• Uses eight electronically controlled/hydraulically actuated fuel injectors.
• Maintains operating pressures between 448-482 kPa (65-70 psi).

The engine lubrication system:

• Is divided into two systems: the low-pressure system lubricates the engine (6007), the high-pressure system actuates the fuel injectors.
• Maintains pressures between 69-414 kPa (10-60 psi) for the low-pressure system and 2,758-20,685 kPa (400-3,000 psi) for the high-pressure system.
• Is cooled by an engine oil cooler.
• In the high-pressure system uses an injection control pressure (ICP) sensor (9F838) and injection pressure regulator (IPR) valve (7A139) to maintain and control pressure.
• Actuates the exhaust back-pressure warm-up system integral to the turbocharger.
• In the high-pressure system is used to inject fuel.