N14 Base Engine Troubleshooting and Repair Manual – Intake Manifold Pressure (Boost) is Below Normal

Symptom Tree  t097

This is symptom tree t097
Cause Correction

Electronic fault codes active or high counts of inactive fault codes

Refer to Section TF in the Troubleshooting and Repair Manual for CELECT™
Plus Systems, 3666130, or Section TF in the Troubleshooting and Repair Manual for CELECT™ Systems, Bulletin 3666084.


Turbocharger is not correct

Check the turbocharger part number and compare it to the Control Parts List (CPL), Bulletin 3379133 or 4021327. Replace the turbocharger if necessary. Refer to Procedure 010-033.


Air intake or exhaust leaks

Inspect the air intake and exhaust systems for air leaks. Refer to Procedure 010-024.


Charge air cooler restricted (if equipped)

Inspect the air cooler for internal and external restrictions. Replace the restricted cooler if necessary. Refer to Procedure 010-027.


Air compressor connection is loose or damaged

Check the connection between the manifold and the air compressor. Repair or replace if necessary.


Air intake system restriction

Check the air intake system for restriction. Refer to Procedure 010-031.


Exhaust system restriction

Check the exhaust system for any restrictions. Refer to Procedure 011-009.


Turbocharger is worn or damaged

Check the turbocharger for damage. Measure the turbine and compressor wheel clearances. Refer to Procedures 010-039.


Engine power output is low

Refer to the Engine Power Output Low symptom tree.

Last Modified:  13-Jan-2004