G3600 A4 Engines Intake Manifold Air Temperature Is High Caterpillar


Intake Manifold Air Temperature Is High
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G3600 A4 Engines [KENR9774]
AIR INLET AND EXHAUST SYSTEM
MANIFOLD GP-INLET
G3600 A4 Engines Intake Manifold Air Temperature Is High
1.1. Probable Causes
2.1. Recommended Actions

Use this procedure in order to troubleshoot a high intake manifold air temperature. Also, use this procedure if one of the following event codes is active or logged.

Table 1
J1939 Code and Description     Comments    
105-0
Engine Intake Manifold #1 Temperature : High - most severe (3)    
The intake manifold air temperature is above the trip point for the programmed delay time.
The code is logged.    
105-15
Engine Intake Manifold #1 Temperature : High - least severe (1)    
The intake manifold air temperature is above the trip point for the programmed delay time.
The code is logged.    
105-16
Engine Intake Manifold #1 Temperature : High - moderate severity (2)    
The intake manifold air temperature is above the trip point for the programmed delay time.
The code is logged.    

Probable Causes

  • Codes

  • Inlet air temperature

  • Coolant temperature

  • Air/Fuel ratio

  • Inlet air restriction

  • Sensor

  • Connectors and wiring

  • Exhaust restriction

  • Engine overload

  • Aftercooler

  • Coolant flow

  • Air flow

Recommended Actions

Table 2
Troubleshooting Test Steps     Values     Results    

1. Check for Codes

A. Connect Cat® Electronic Technician (ET) to the service tool connector.

B. Look for active codes that are associated with the system for the event code.
   

Codes
   

Result: An associated code is active.

Repair: Troubleshoot any associated codes before continuing with this test.

Result: A code is active or logged.

Proceed to Test Step 2.
   

2. Check for High Inlet Air Temperature
   

Temperature
   

Result: The inlet air temperature is OK.

Proceed to Test Step 3.

Result: The inlet air temperature is NOT OK.

Repair: Determine the reason for high inlet air temperatures. Repair or replace damaged components.

If the problem is not resolved, proceed to Test Step 3.
   

3. Check for High Coolant Temperature

A. Refer to Troubleshooting, "Coolant Temperature Is High" for additional information.
   

Temperature
   

Result: The coolant temperature is OK.

Proceed to Test Step 4.

Result: The coolant temperature is NOT OK.

Repair: Determine the reason for high coolant temperatures. Repair or replace damaged components.

If the problem is not resolved, proceed to Test Step 4.
   

4. Check the Air/Fuel Ratio

Note: If the air/fuel mixture is too lean, compression of the higher volume of air through the turbocharger will increase the temperature.

A. Obtain a fuel analysis.

Note: If the quality of the gas is inconsistent, obtain several analyses over a period of time.

B. Enter the data into AVSpare Software, LERW4485, "Gas Engine Rating Pro (GERP)".

C. Verify that the fuel supply pressure is adequate and stable.

D. Verify that the exhaust emissions are correct.
   

Air/Fuel Ratio
   

Result: The air/fuel ratio is OK.

Proceed to Test Step 5.

Result: The air/fuel ratio is NOT OK.

Repair: Use Cat ET to program the results for the "Fuel Specific Heat Ratio", "Fuel Quality", and "Gas Specific Gravity" parameters. Refer to Systems Operation, "Electronic Control System Parameters" for additional information.

Program the "Fuel Quality" parameter to the average value of the LHV. Adjust the engine operation according to Testing and Adjusting, "BTU and Precombustion Chamber Adjustments".

If the problem is not resolved, proceed to Test Step 5.
   

5. Check for a Restriction in the Inlet Air System

Note: Inlet air restriction can cause uneven exhaust port temperatures. Cylinders at the front half of the engine may have exhaust port temperatures that are lower than the exhaust port temperatures for the cylinders at the rear half of the engine by 10 to 20 °C (18 to 36 °F).

A. Check the air filter restriction indicator, if equipped. Refer to the Operation and Maintenance Manual for additional information.

B. Measure the inlet air restriction for each turbocharger. Refer to Troubleshooting, "Inlet Air Is Restricted" for additional information.

Note: High cylinder temperatures can cause a high coolant temperature.
   

Restriction
   

Result: The inlet air restriction is OK.

Proceed to Test Step 6.

Result: The inlet air restriction is NOT OK. An imbalance in the system is discovered.

Repair: Repair or replace damaged inlet air system components. Equalize the inlet air restriction for each of the turbochargers.

If the problem is not resolved, proceed to Test Step 6.
   

6. Check the Intake Manifold Temperature Sensor

A. Allow the sensor to cool and remove the sensor.

B. Connect Cat ET.

C. Use Cat ET to monitor the following temperatures:

- "Intake Manifold Temperature"
- "Ambient Temperature"

Note: The reading and the ambient temperature are approximately equal.
   

Sensor
   

Result: The temperature sensor is working properly.

Proceed to Test Step 8.

Result: The temperature sensor is not working properly.

Proceed to Test Step 7.
   

7. Inspect the Electrical Connectors and the Wiring

A. Turn the main disconnect switch to the OFF position.

B. Thoroughly inspect the connectors. Refer to Troubleshooting, "Electrical Connectors-Inspect" for additional information.

C. Perform a
45 N (10 lb) pull test on the connector wires.

D. Check the harness for abrasions and pinch points.
   

Connectors and Wiring
   

Result: The connectors and wiring appear to be OK.

Repair: Replace the sensor.

If the problem is not resolved, proceed to Test Step 8.

Result: There is a problem with the connectors and/or wiring.

Repair: Repair or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are coupled.

If the problem is not resolved, proceed to Test Step 8.
   

8. Check for a Restriction in the Exhaust System

Note: A restriction of the exhaust can cause high cylinder temperatures.

A. Measure the exhaust restriction during engine operation with a load. For data that is specific to your engine, refer to the Technical Marketing Information (TMI).
   

Restriction
   

Result: The exhaust restriction measurement is OK.

Proceed to Test Step 9.

Result: The exhaust restriction measurement is NOT OK.

Repair: Repair or replace damaged exhaust system components.

If the problem is not resolved, proceed to Test Step 9.
   

9. Check for Engine Overload

Note: When the load that is applied to the engine is too large, the engine will run in the lug condition. When the engine is running in the lug condition, engine rpm does not increase with an increase of fuel.
   

Load
   

Result: The engine is not being overloaded.

Proceed to Test Step 10.

Result: The engine is being overloaded.

Repair: Reduce engine load to an acceptable limit.

If the problem is not resolved, proceed to Test Step 10.
   

10. Check for a High Inlet Temperature for the Cooling Water Through the Aftercooler

A. Compare the reading to the regulated temperature.
   

Temperature
   

Result: The inlet water temperature is OK.

Proceed to Test Step 11.

Result: The inlet water temperature is NOT OK.

Repair: Determine the reason for inlet water temperature is high. Repair or replace damaged components.

If the problem is not resolved, proceed to Test Step 11.
   

11. Check for Insufficient Flow of Cooling Water Through the Aftercooler

A. Check the outlet temperature of the coolant for the aftercooler.

B. Compare the reading to the inlet temperature of the coolant for the aftercooler.

Note: A high temperature differential indicates an insufficient flow rate.
   

Restriction
   

Result: The differential temperature is OK.

Repair: Proceed to Test Step 12.

Result: The differential temperature is NOT OK.

Repair: The coolant flow is restricted. Clean or replace the aftercooler.

If the problem is not resolved, proceed to Test Step 12.
   

12. Check for Insufficient Flow of Air Through the Aftercooler

A. Determine the pressure differential of the inlet air across the aftercooler. For specific data, refer to the TMI for your engine.
   

Restriction
   

Result: The pressure differential is NOT OK.

Repair: Clean or replace the aftercooler.

Verify that the repair eliminated the problem.
   

If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).