3512C and 3516C Marine Auxiliary Engines Caterpillar

Intake Manifold Air Temperature Is High

Usage:

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

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Table 1
Event Code
J1939 Code and Description	Conditions which Generate this Code	System Response
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. The ECM may derate the engine or shutdown the engine.
105-16 Engine Intake Manifold #1 Temperature : High - moderate severity (2)
105-0 Engine Intake Manifold #1 Temperature : High - most severe (3)

Probable Causes

High coolant temperature
High ambient air temperature
Air inlet restriction
Exhaust restriction
Altitude
Engine Overload

Recommended Actions

Note: The procedures have been listed in order of probability. Complete the procedures in the order of the listed test steps.

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Table 2
Troubleshooting Test Step	Value	Result
1. Active Codes and Logged Codes A. Establish communication between Caterpillar Electronic Technician (ET) and the Electronic Control Module (ECM). B. Monitor the diagnostic codes on Cat ET. Check for active or logged diagnostic codes. Specifically check for codes that could be associated to high intake manifold temperature. Refer to the histogram information for engine derates in Cat ET. Note: Wait at least 30 seconds in order for diagnostic codes to become active. C. If the histograms contain derates and no diagnostic codes are present, then the engine is operating normally.	Codes	Result: A diagnostic code is present. Repair: Troubleshoot any codes before continuing with this procedure. Verify that the repair eliminated the problem. Reset the histogram. Result: A diagnostic code is not present. Proceed to Test Step 2.
2. High Coolant Temperature A. Check for a high coolant temperature for the engine. Refer to Troubleshooting, "Coolant Temperature Is High".	Temperature	Result: The coolant temperature is OK. Proceed to Test Step 3. Result: The coolant temperature is NOT OK. Repair: Determine the cause of the high coolant temperature and correct the problem. Verify that the repair eliminated the problem.
3. High Ambient Air Temperature A. Determine if the ambient air temperature is within the design specifications for the cooling system.	Temperature	Result: The ambient air temperature is OK. Proceed to Test Step 4. Result: The ambient air temperature is NOT OK. Repair: Determine the cause of the high ambient air temperature and correct the problem. Verify that the repair eliminated the problem.
Check for a restriction in the air inlet system. A restriction of the inlet air can cause high cylinder temperatures. High cylinder temperatures cause higher than normal temperatures in the cooling system. The coolant temperature must be within the correct range in order to cool the intake air. 4. Inlet Air Restriction A. Check for inlet air restriction. Refer to Troubleshooting, "Inlet Air Is Restricted".	Restriction	Result: The inlet air is not restricted. Proceed to Test Step 5. Result: The inlet air is restricted. Repair: Determine the reason for high inlet air restriction and repair. Verify that the repair eliminated the problem.
Check for a restriction in the exhaust system. A restriction of the exhaust can cause high cylinder temperatures. 5. Exhaust Restriction 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 measures OK. Proceed to Test Step 6. Result: The exhaust restriction measurement is NOT OK. Repair: Verify if the problem has been resolved. Verify that the repair eliminated the problem.
The cooling capability of the cooling system is reduced at higher altitudes. A pressurized cooling system that is large enough to keep the coolant from boiling must be used. Make sure that the settings for the engine are correct for the altitude. 6. Altitude A. Make sure that the settings for the engine are correct for the altitude.	Setting	Result: The engine setting are correct for the altitude. Proceed to Test Step 7. Result: The engine settings are not correct for the altitude. Repair: Correct the settings. Verify that the repair eliminated the problem.
The engine may be running in the lug condition. 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. This lower engine rpm causes a reduction in coolant flow through the system. 7. Engine Overload A. Determine if the engine is being overloaded	Load	Result: The engine is not being overloaded. Result: The engine is being overloaded. Repair: Reduce engine load to an acceptable limit. 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).