Hummer H3. Manual — part 265

Fig. 664: View Of Engine Lubrication System

2006 Hummer H3

2006 ENGINE Engine Mechanical - 3.5L (L52) - H3

Courtesy of GENERAL MOTORS CORP.

The engine lubrication system is of the force-feed type. The oil is supplied under full pressure to
the crankshaft, connecting rods, valve lash adjusters, and cam phasing system. A controlled
volume of oil is supplied to the camshaft and valve rocker arms. Gravity flow or splash lubricates
all other parts. The engine oil is stored in the oil pan, which is filled through a fill cap in the
camshaft cover. A removable oil level indicator, on the right side of the engine block, is provided
to check the oil level. The oil pump is located in the engine front cover and is driven by the
crankshaft. It is a gerotor-style pump, which is a combination of a gear, and a rotor pump. It is
connected by a passage in the cylinder block to an oil screen and pipe assembly. The screen is
submerged in the oil supply and has ample volume for all operating conditions. Oil is drawn into
the pump through the screen and pipe assembly, and a passage in the crankcase, connecting to the
passages in the engine front cover. Oil is discharged from the oil pump to the oil filter. The oil
pressure relief valve limits the oil pressure. The oil filter bypass valve opens when the oil filter is
restricted to approximately 68.95 kPa (10 psi) of pressure difference between the oil filter inlet
and discharge. The oil will then bypass the oil filter and channel unfiltered oil directly to the main
oil galleries of the engine. A full-flow oil filter is mounted to the oil filter adapter on the lower
right front side of the engine. The main oil galleries run the full length of the engine block and cut
into the valve lash adjuster holes to supply oil at full pressure to the valve lash adjusters. Holes
are drilled from the crankshaft bearings to the main oil gallery. Oil is transferred from the
crankshaft bearings to the connecting rod bearings through holes drilled in the crankshaft. Pistons,
piston pins, and cylinder walls are lubricated by oil splash from the crankshaft and connecting
rods. The camshafts and valve rocker arms are supplied with oil from the oil passages drilled into
the camshaft mounting areas.

CLEANLINESS AND CARE

An automobile engine is a combination of many of the following surfaces:

Machined

Honed

Polished

Lapped

The tolerances of these surfaces are measured in the ten-thousandths of an inch. When you service
any internal engine part, cleanliness and care are important. Apply a liberal coating of engine oil
to the friction areas during assembly in order to protect and lubricate the surfaces on initial
operation. Throughout this section, practice proper cleaning and protection procedures to the
machined surfaces and to the friction areas.

2006 Hummer H3

2006 ENGINE Engine Mechanical - 3.5L (L52) - H3

Whenever you remove the valve train components, keep the components in order. Follow this
procedure in order to install the components in the same locations and with the same mating
surfaces as when removed.

Disconnect the negative battery cables before you perform any major work on the engine. For
more information on the disconnection of the battery, refer to Engine Electrical.

SEPARATING PARTS

The components of an internal combustion engine develop wear patterns with their mating
components. During disassembly of the engine, parts should be separated and kept in order so
they may be reinstalled in the same location from which they were removed.

REPLACING ENGINE GASKETS

1. Do not reuse any gasket unless otherwise specified. Reusable gaskets will be identified in

the service procedure. Do not apply sealant to any gasket or sealing surface unless called out
in the service procedure.

2. Use jack screws to separate components.

NOTE:

Engine damage may result if an abrasive paper, pad, or motorized
wire brush is used to clean any engine gasket surfaces.

CAUTION: Refer to Battery Disconnect Caution in Cautions and Notices.

IMPORTANT: Do not use any other method or technique in order to remove

the gasket material from a components.
Do not use the following items in order to clean the gasket
surfaces:

Abrasive pads

Sand paper

Power tools

These methods of cleaning may damage the component.
Abrasive pads also produce a fine grit that the oil filter
cannot remove from the oil. This grit is abrasive and may

2006 Hummer H3

2006 ENGINE Engine Mechanical - 3.5L (L52) - H3

3. Remove all of the gasket and the sealing material from the component using a plastic or a

wood scraper. Do not gouge or scrape the sealing surfaces.

4. When assembling components, use only the sealant specified in the service procedure.

Ensure that the sealing surfaces are clean and free of debris or oil. When applying sealant to
a component, apply a bead size as specified in the service procedure.

5. Tighten the bolts to the specifications.

USE OF ROOM TEMPERATURE VULCANIZING (RTV) AND ANAEROBIC SEALER

Sealant Types

The following 2 major types of sealant are commonly used in engines:

Aerobic sealant (Room Temperature Vulcanizing (RTV))

Anaerobic sealant, which include the following:

Gasket eliminator

Pipe

Threadlock

Aerobic Type Room Temperature Vulcanizing (RTV) Sealant

Aerobic type Room Temperature Vulcanizing (RTV) sealant cures when exposed to air. This type
of sealant is used where 2 components (such as the intake manifold and the engine block) are
assembled together.

cause internal engine damage.

IMPORTANT: Do not allow the sealant to enter any blind threaded holes.

The sealant may cause the following conditions:

Prevent you from properly seating the bolt

Cause damage when you tighten the bolt

IMPORTANT: The correct sealant and amount of sealant must be used in the

proper location to prevent oil leaks, coolant leaks, or the
loosening of the fasteners. DO NOT interchange the sealants. Use
only the sealant (or equivalent) as specified in the service
procedure.

2006 Hummer H3

2006 ENGINE Engine Mechanical - 3.5L (L52) - H3