C175 Petroleum Engine Caterpillar

Intake Manifold Air Temperature Is High

Usage:

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

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Table 1
J1939 Code and Description	CDL Code and Description	Comments
105-0 Engine Intake Manifold #1 Temperature : High - most severe (3)	E539 (3) High Intake Manifold Air Temperature	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)	E539 (1) High Intake Manifold Air Temperature	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)	E539 (2) High Intake Manifold Air Temperature	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
Inlet air restriction
Exhaust restriction
Engine overload
Aftercooler

Recommended Actions

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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 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 °C to 20 °C (18 °F 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 5. 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 5.
5. 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.	Restriction	Result: The exhaust restriction measurement is OK. Proceed to Test Step 6. 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 6.
6. 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 7. Result: The engine is being overloaded. Repair: Reduce engine load to an acceptable limit. If the problem is not resolved, proceed to Test Step 7.
7. 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 8. 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 8.
8. 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 9. 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 9.
9. Check for Insufficient Flow of Air Through the Aftercooler A. Determine the pressure differential of the inlet air across the aftercooler.	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).