3516E Engine for 994K Wheel Loaders Caterpillar

Exhaust Temperature Is High

Usage:

994K MM9

Use this procedure to troubleshoot a high exhaust 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
173-0 Engine Exhaust Gas Temperature : High - most severe (3)	E194 (3) High Exhaust Temperature	The exhaust gas temperature is higher than expected for the engine operating conditions.
173-15 Engine Exhaust Gas Temperature : High - least severe (1)	E194 (1) High Exhaust Temperature	The exhaust gas temperature is higher than expected for the engine operating conditions.
173-16 Engine Exhaust Gas Temperature : High - moderate severity (2)	E194 (2) High Exhaust Temperature	The exhaust gas temperature is higher than expected for the engine operating conditions.

If the engine is shutdown due to a high exhaust temperature, the power to the engine Electronic Control Module (ECM) must be cycled to restart the engine.

Probable Causes

Codes
Intake air temperature
Inlet air restriction
Engine overload
Exhaust restriction
Deposits or leaks

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 Intake Air Temperature Note: A one degree increase in the intake manifold temperature will increase the exhaust temperature by approximately three degrees. A. Refer to Troubleshooting, "Intake Manifold Air Temperature Is High" for additional information.	Temperature	Result: The intake manifold air temperature is OK. Proceed to Test Step 3. Result: The intake manifold air temperature is NOT OK. Repair: Determine the cause of the high intake manifold air temperature and correct the problem. If the problem is not resolved, proceed to Test Step 3.
3. 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.	Restriction	Result: The inlet air restriction is OK . Proceed to Test Step 4. 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 4.
4. 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 5. Result: The engine is being overloaded. Repair: Reduce engine load to an acceptable limit. 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. 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 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 Heavy Buildup of Deposits in the Cylinder or Internal Oil Leaks A. Use a borescope to inspect the cylinders. Look for the following conditions: - Deposits on the valve seats - Deposits on the valve faces - Deposits on the cylinder walls that are above the upper limit of the piston stroke - Signs of internal oil leaks	Deposits and Leaks	Result: The cylinder check is NOT OK. Repair: Repair or replace damaged components. 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).