Engine Assembly

WARNING: This page is about a different car, the 2024 Jeep Grand Wagoneer L and 2024 Jeep Grand Wagoneer. However, it is still accessible from the selected car via links, so may be relevant.

ENGINE BLOCK

The engine block is made of aluminum. It is a single block that includes the cylinders, coolant cavities and oil galleries.

The cylinder bores contain a steel spray bore coating.

On the exhaust side of the engine block there are mounting surfaces and related cavities for the following components:

Water pump with Ball Valve Thermostat (BVT)
Coolant pump

On the intake side of the engine block there are mounting surfaces for the following components:

Oil cooler
Fuel pumps

On the intake side of the transmission mounting flange, you can see the surface with the readable engine identification along with a QR Code scannable code symbol and the port for the engine block heater (dealer installed accessory only available for cold climates).

On the timing side of the engine block is a bore for the fuel pump camshaft on the intake side of the block.

The following information is shown on the surface of the exhaust side of the engine block:

Cylinder tolerance classes
Upper crankshaft main bearing tolerance classes

CRANKSHAFT

The engine drive components are designed to reduce overall rotational friction forces.

The crankshaft is made of steel. The main journals are numbered starting from the timing side (1st cylinder):

The crankshaft main journals rotate on main bearings located in the engine block. Aluminum alloy half-bearings are used (upper and lower) to reduce dragging friction. Along the outside diameter of the upper half-bearing, there is a hole to allow engine oil to enter. Along the inside diameter there is the groove that allows lubrication of the crankshaft main journal and provides oil to the crank pin lubrication drilling. On both the half-bearings there is the centering "tang".

The crankshaft axial clearance is adjusted by two half-rings located at the 4th main journal.

An arrow stamped on the lower surface of each main bearing cap indicates the direction in which the bearing cap should be mounting on the engine block. The bearing cap must be mounted with the arrow pointing towards the timing side.

Data regarding the following bearing tolerance classes can be found on the front of the crankshaft (timing side):

Lower crankshaft main bearing tolerance classes
Connecting rod big end bearing tolerance classes

PISTON AND CONNECTING ROD

The connecting rods are in forged steel. The big end (cap) is split so that it can be separated.

Bearing class sizes are ink stamped on the ID running surface. These sizes must be determined using a selection matrix. Block main bore size and crank journal size class must be used to determine the correct bearing grade for the specific locations.

The pistons are made of cast aluminum alloy with a graphite coating.

Indentations on the piston crown allow for intake valve clearance. There is a hollow area "dish" at the center of the piston crown that helps create the right amount of turbulence to mix the fuel and air.

The pistons have the following features:

Piston crown hollow area (dish)
Clearance for intake valves
Arrow that indicates the timing side
Part number
Class indication

Combustion chamber pressure is captured by two compression rings, the first groove compression ring and the second groove compression ring. The ring that scrapes the oil from the cylinder walls, the oil control ring, is in the third groove.