Section 91 (3.7L Engine (Service Information)): Lubrication: Operation

WARNING: This page is about a different car, the 2004 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.

Oil from the oil pan is pumped by a gerotor type oil pump directly mounted to the crankshaft nose. Oil pressure is controlled by a relief valve mounted inside the oil pump housing. For lubrication flow refer to (Fig 1 )

The camshaft exhaust valve lobes and rocker arms are lubricated through a small hole in the rocker arm; oil flows through the lash adjuster then through the rocker arm and onto the camshaft lobe. Due to the orientation of the rocker arm, the camshaft intake lobes are not lubed in the same manner as the exhaust lobes. The intake lobes are lubed through internal passages in the camshaft. Oil flows through a bore in the No. 3 camshaft bearing bore, and as the camshaft turns, a hole in the camshaft aligns with the hole in the camshaft bore allowing engine oil to enter the camshaft tube. The oil then exits through 1.6mm (0.063 in.) holes drilled into the intake lobes, lubricating the lobes and the rocker arms.

ENGINE LUBRICATION FLOW CHART - BLOCK:

FROM

Oil Pickup Tube

Oil Pump

Oil Filter

Block Main Oil Gallery

Crankshaft Main Journal
Left Cylinder Head⁽¹⁾
Right Cylinder Head⁽¹⁾
Counterbalance Shaft Rear Journal

Crankshaft Main Journals

Crankshaft Rod Journals

Crankshaft Number One Main Journal

Front Timing Chain Idler Shaft
Counterbalance Shaft - Front Journal
Both Secondary Chain Tensioners

Left Cylinder Head

Refer to ENGINE LUBRICATION FLOW CHART - CYLINDER HEADS: TABLE 2

Right Cylinder Head

Refer to ENGINE LUBRICATION FLOW CHART - CYLINDER HEADS: TABLE 2

⁽¹⁾	The cylinder head gaskets have an oil restricter to control oil flow to the cylinder heads

ENGINE LUBRICATION FLOW CHART - CYLINDER HEADS:

FROM

Cylinder Head Oil Port (in bolt hole)

Diagonal Cross Drilling to Main Oil Gallery

Main Oil Gallery (drilled through head from rear to front)

Base of Camshaft Towers
Lash Adjuster Towers

Base of Camshaft Towers

Vertical Drilling Through Tower to Camshaft Bearings⁽¹⁾

Lash Adjuster Towers

Diagonal Drillings to Hydraulic Lash Adjuster Pockets

⁽¹⁾	The number three camshaft bearing journal feeds oil into the hollow camshaft tubes. Oil is routed to the intake lobes, which have oil passages drilled into them to lubricate the rocker arms.

Fig 1: Identifying Lubrication Oil Flow

Courtesy of DAIMLERCHRYSLER CORP.