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Home >> Dodge and Ram >> 2007 >> Durango 3.7 K >> Repair and Diagnosis >> Engine Performance >> System >> DTC U1418, Pre-Diagnostic Troubleshooting Procedure, Intermittent Condition Check, System Checks, Symptom Tests, Pcm/ECM Programming, Powertrain Verification Test >> *Checking The Exhaust System For Leaks >> Diagnostic Test
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Diagnostic Test

  1. 1) CHECKING THE EXHAUST SYSTEM FOR LEAKS 

    Turn the ignition off.

    Raise the vehicle in accordance with the Service Information.

    WARNING: The normal operating temperature of the exhaust system is very high. Never work around or attempt to service any part of the exhaust system until it has cooled. Special care should be taken when working near the catalytic converter. The temperature of the converter rises to a high level after a short period of engine operating time

    Connect Exhaust Cone #8404-EC or #8404-EC to Air Pressure Regulator (with hose) #W-18-MIL-1146AS.

    CAUTION: The air pressure must not exceed 27.6 kPa (4 psi), otherwise engine damage can occur.

    Attach shop air to the air pressure regulator.

    Adjust the Air Pressure Regulator to 27.6 kPa (4 psi)

    Insert the exhaust cone into the vehicle tail pipe.

    If the vehicle is equipped with dual exhaust. Use the #8404-ECT with equipped attached plug, plug one side of the dual exhaust pipe. Pressurize the other as described above.

    Apply Mopar® Air Leak Detector PN# 05191804AA (or an equivalent leak finder liquid) to the following areas:

    - All welded joints from the exhaust manifold to 152.4 mm (6 inches) behind the downstream O2 sensor

    - O2 sensor seal points

    - O2 sensor boss welds

    - Flange/joint connection(s)

    - Exhaust manifold to cylinder head connection(s)

    - EGR solenoid gasket base and tube seal points (if equipped)

    Watch for the Mopar® Air Leak Detector PN# 05191804AA (or the equivalent leak finder liquid) to bubble.

    Use the following definitions to help determine if system or component repair/replacement is necessary:

    Type 1 Leak  is defined as a leak where very small foam like bubbles 1 mm (0.04 of an inch) or less appear.

    Any Type 1 or greater leaks found in welded joints, O2 sensor seal points or O2 sensor boss welds must be repaired or the component must be replaced.

    Type 2 Leak  is defined as a leak where larger bubbles pea size, 8 mm (0.3 of an inch) or greater appear.

    Any Type 2 or greater leaks found in flange or joint connections, exhaust manifold to cylinder head connections, or EGR gasket and tube seal points must be repaired or the components must be replaced

    Leak Location  Repair required if results at 27.6 kPa (4 psi) reveal bubble size: 
    Welded joints Type 1, 1 mm (0.04 of an inch) or greater
    O2 Sensor seal points Type 1, 1 mm (0.04 of an inch) or greater
    O2 Sensor boss welds Type 1, 1 mm (0.04 of an inch) or greater
    Flange/joint connections Type 2, 8 mm (0.3 of an inch) or greater
    Exhaust Manifold to cylinder head connections Type 2, 8 mm (0.3 of an inch) or greater
    EGR gasket and tube seal points Type 2, 8 mm (0.3 of an inch) or greater

    If a leak is found that matches the above definition, repair or replace the component as necessary.

    Once the repair is complete, repeat the procedure to verify that all leaks have been repaired.

    Were any exhaust leaks found? 

    Yes 

    1. Repair or replace the leaking exhaust parts as necessary.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Test complete.