Hummer H3. Manual — part 85

4

and at varying speeds.

3. Park the vehicle on a level surface, over a

large sheet of paper or other clean surface.

4. Wait 15 minutes.

5. Identify the type of fluid, and the

approximate location of the leak.

Can you identify the type of fluid and the
approximate location of the leak?

Go to Step 10

Go to Step 5

5

1. Visually inspect the suspected area. Use a

small mirror to assist in looking at hard to
see areas.

2. Check for leaks at the following locations:

Sealing surfaces

Fittings

Cracked or damaged components

Can you identify the type of fluid and the
approximate location of the leak?

Go to Step 10

Go to Step 6

6

1. Completely clean the entire engine and

surrounding components.

2. Apply an aerosol-type powder (baby

powder, foot powder, etc.) to the suspected
area.

3. Operate the vehicle for several kilometers

(miles) at normal operating temperature
and at varying speeds.

4. Identify the type of fluid, and the

approximate location of the leak, from the
discolorations in the powder surface.

Can you identify the type of fluid and the
approximate location of the leak?

Go to Step 10

Go to Step 7

1. Visually inspect the suspected area. Use a

small mirror to assist in looking at hard to
see areas.

2006 Hummer H3

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

7

2. Check for leaks at the following locations:

Sealing surfaces

Fittings

Cracked or damaged components

Can you identify the type of fluid and the
approximate location of the leak?

Go to Step 10

Go to Step 8

8

Use J 28428-E High Intensity Black Light to
identify the type of fluid, and the approximate
location of the leak. See Special Tools. Refer to
the manufacturer's instructions when using the
tool.
Can you identify the type of fluid and the
approximate location of the leak?

Go to Step 10

Go to Step 9

9

1. Visually inspect the suspected area. Use a

small mirror to assist in looking at hard to
see areas.

2. Check for leaks at the following locations:

Sealing surfaces

Fittings

Cracked or damaged components

Can you identify the type of fluid and the
approximate location of the leak?

Go to Step 10

System OK

10

1. Inspect the engine for mechanical damage.

Special attention should be shown to the
following areas:

Higher than recommended fluid levels

Higher than recommended fluid
pressures

Plugged or malfunctioning fluid filters
or pressure bypass valves

Plugged or malfunctioning engine
ventilation system

Improperly tightened or damaged
fasteners

2006 Hummer H3

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

CRANKCASE VENTILATION SYSTEM INSPECTION/DESCRIPTION

Crankcase Ventilation (CV) System Inspection

Cracked or porous components

Improper sealants or gaskets where
required

Improper sealant or gasket installation

Damaged or worn gaskets or seals

Damaged or worn sealing surfaces

2. Inspect the engine for customer

modifications.

Is there mechanical damage, or customer
modifications to the engine?

Go to Step 11

System OK

11

Repair or replace all damaged or modified
components.
Does the engine still leak oil?

Go to Step 1

System OK

2006 Hummer H3

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

Fig. 27: View Of Crankcase Ventilation System
Courtesy of GENERAL MOTORS CORP.

Test for vacuum at the positive crankcase ventilation (PCV) dirty air hose (2) where it
connects to the vacuum orifice tube (5) in the camshaft cover. There should be manifold
vacuum present at the hose (2). If there is no vacuum, inspect for a plugged hose, leaking
hose or a plugged intake manifold passage.

If oil has accumulated in the air cleaner resonator (1), inspect for the following conditions:

2006 Hummer H3

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