Cylinder Leakage Test

Engine Mechanical - 3.0L LM2 Diesel | Diagnostic Information and Procedures | Document ID: 5532163 Special Tools EN-46722 Compression Gauge Adapter Equivalent regional tools: Special Tools Removal Procedure

1. Oil Filler Cap » Remove

Cylinder Leakage Test — figure 1

2. Intake Manifold Cover Bolt (1) » Remove
3. Intake Manifold Cover (2) » Remove
4. Install the oil filler cap after removal of the intake manifold cover to prevent debris from falling into the engine.

Cylinder Leakage Test — figure 2

5. Charge Air Cooler Outlet Air Hose Clamp (1) » Loosen until disengaged [2x]
6. Charge Air Cooler Outlet Air Hose (2) » Remove

Cylinder Leakage Test — figure 3

7. Disconnect the throttle body electrical connector.
8. Throttle Body Bolt (1) » Remove [3x]
9. Throttle Body (2) » Remove
10. Throttle Body Gasket (3) » Remove and DISCARD

Cylinder Leakage Test — figure 4

11. Electrical Connector (1) @ Glow Plug » Disconnect [6x]

Cylinder Leakage Test — figure 5

Caution

Ensure each glow plug is fully intact when removed from the cylinder head. A broken tip could remain within the combustion chamber, which may not be obvious during removal. Damage to the engine may result if a broken glow plug tip remains within the engine.

Note

Do not use power tools to install glow plugs. Cylinder head removal may be required to retrieve a broken tip.

12. Glow Plug (1) » Remove and DISCARD [6x]
13. Inspect each glow plug tip and ensure the glow plug is not broken. If a broken tip is suspected, inspect the combustion chamber for the glow plug tip. Cleaning and Inspection Procedure - Required

Cylinder Leakage Test — figure 6

1. Inspect the charge air cooler outlet air hose (2): 1.1. Use dish soap and water to clean the inside of the charge air cooler outlet air hose (2). Clean the interior of the hose, and allow to completely dry. Ensure any oil residue is removed from the hose internal interface surfaces. 1.2. Inspect the interior of the charge air cooler outlet air hose (2) for tears or delamination. Replace the hose if damage is found. 1.3. Inspect the charge air cooler outlet air hose clamps (1). Replace the charge air cooler outlet air hose (2) if damage is found or the clamp components are missing. Measurement Procedure
2. Rotate the crankshaft to place the piston in the cylinder being tested at top dead center (TDC) of the compression stroke.

Note

It may be necessary to hold the crankshaft balancer bolt to prevent the engine from rotating.

2. Install a suitable leakdown tester and EN-46722 Compression Gauge Adapter .
3. Apply shop air pressure to the tester and adjust according to the manufacturers instructions.

Note

A leakage test may be performed to measure cylinder/combustion chamber leakage. High cylinder leakage may indicate one or more of the following: Worn, burnt, or stuck valves Broken valve springs Incorrect valve lash Damaged valve train components Damaged piston Worn piston rings Worn or scored cylinder bore Damaged cylinder head gasket Cracked or damaged cylinder head Cracked or damaged engine block

4. Record the cylinder leakage value. Cylinder leakage that exceeds 25 percent is considered excessive and may require component service. In excessive leakage situations, inspect for the following conditions: Air leakage sounds at the intake manifold tube, may indicate a worn, stuck or burnt intake valve, broken valve spring, incorrect valve lash or damaged valve train components. Air leakage sounds at the exhaust system tailpipe may indicate a worn, burnt, or stuck exhaust valve, broken valve spring, incorrect valve lash or damaged valve train components. Air leakage sounds from the crankcase, oil level indicator tube, or oil fill tube may indicate worn piston rings, a damaged piston, a worn or scored cylinder bore, a damaged engine block or a damaged cylinder head. Air bubbles in the cooling system may indicate a damaged cylinder head or gasket.
5. Remove the leakdown tester and EN-46722 Compression Gauge Adapter .
6. Perform the leakage test on the remaining cylinders and record the values. Installation Procedure

Caution

Refer to Component Fastener Tightening Caution.

Note

The ceramic glow plug technology is sensitive to collision, drops, or general impact Avoid side force or the bending of the tip during the installation in the head. Replace the glow plug if one or more of these conditions is suspected.

Note

Do not use power tools to install glow plugs.

1. Glow Plug (1) » Install and tighten [6x] — Fastener Specifications

2. Electrical Connector (1) @ Glow Plug » Connect [6x]

3. Throttle Body Gasket (3) » Install NEW

4. Throttle Body (2) » Install

Caution

Refer to Fastener Caution.

5. Throttle Body Bolt (1) » Install and tighten [3x] — Fastener Specifications

6. Connect the throttle body electrical connector.

7. Charge Air Cooler Outlet Air Hose (2) » Install

8. Charge Air Cooler Outlet Air Hose Clamp (1) » Tighten [2x] — Fastener Specifications

9. Oil Filler Cap » Remove

10. Intake Manifold Cover (2) » Install

11. Intake Manifold Cover Bolt (1) » Install and tighten — Fastener Specifications

12. Oil Filler Cap » Install