C175 Tier 4 Final Engines for Off-Highway Trucks Caterpillar

Exhaust Has Excessive White Smoke

Usage:

793F D3T

Use this procedure to troubleshoot exhaust with excessive white smoke.

Note: Some white smoke may be present during cold start-up conditions when the engine is operating normally. If the white smoke persists, there may be a problem.

Probable Causes

Cold mode (if equipped)
Starting aids (if equipped)
Software
Cooling system
Fuel system
Fuel injectors

Recommended Actions

Show/hide table

Table 1
Troubleshooting Test Steps	Values	Results
1. Check for Cold Mode Operation Note: Cold mode is activated whenever the engine coolant temperature falls below a predetermined value. A. Connect Cat^® Electronic Technician (ET) to the service tool connector. B. Use Cat ET to monitor the following: - Coolant temperature C. Use Cat ET to verify that "Cold Mode" is exited. Note: During cold mode operation, condensation may be present and is normal.	Cold Mode	Result: The engine is operating in cold mode. Repair: Normal operation. Return to service. Result: The engine is not operating in cold mode. Proceed to Test Step 2.
2. Check the Starting Aids A. If cold ambient conditions exist, check operation of starting aids. Verify that the starting aid is operating correctly. Refer to the appropriate circuit test for additional information. B. If ether bottles are not installed, use Cat ET to verify that ether is not enabled.	Starting Aid	Result: The starting aid is operating correctly. Proceed to Test Step 3. Result: The starting aid is not operating correctly. Repair: Repair or replace damaged components. If the problem is not resolved, proceed to Test Step 3.
3. Ensure that the latest Flash File Software is Installed in the ECM A. Connect Cat ET. B. Use Cat ET to verify that the correct flash file is being used.	Flash File	Result: The latest flash file is installed. Proceed to Test Step 4. Result: The latest flash file is not installed. Repair: Perform the following procedure: 1. Download the latest flash file from SIS web. 2. Install the software into the ECM. Refer to Troubleshooting, "ECM Software - Install" for additional information. If the problem is not resolved, proceed to Test Step 4.
4. Inspect the Cooling System A. Check for an internal coolant leak into the cylinder and/or the exhaust. Refer to Systems Operation/Testing and Adjusting, "Cooling System" for additional information.	Internal Coolant Leak	Result: There is not an internal coolant leak. Proceed to Test Step 5. Result: There is an internal coolant leak. Repair: Repair or replace damaged components. If the problem is not resolved, proceed to Test Step 5.
5. Inspect the Fuel System A. Visually check the fuel level in the fuel tank. Do not rely on the fuel gauge only. B. Ensure that the vent in the fuel cap is not filled with debris. C. Ensure that the fuel supply valve (if equipped) is in the full OPEN position. Note: Cold weather adversely affects the characteristics of the fuel. Refer to the engines Operation and Maintenance Manual for information on improving the characteristics of the fuel during cold-weather operation. D. Check fuel quality. Check the fuel tank for debris or foreign objects which may block the fuel supply. E. Check for fuel leaks.	Fuel System	Result: The fuel system is OK. Proceed to Test Step 6. Result: The fuel system is NOT OK. Repair: Repair or replace damaged fuel system components. If the problem is not resolved, proceed to Test Step 6.
6. Perform a Cylinder Cutout Test A. Connect Cat ET. B. Perform a cylinder cutout test to determine which cylinder is causing the white smoke complaint.	Cylinder Cutout Test	Result: The white smoke was isolated to a single cylinder. Repair: A failed fuel injector has been detected. Release the pressure in the high-pressure rail by loosening the end plug on one of the last two fuel accumulators. Refer to Testing and Adjusting, "Fuel Rail Pressure - Release" for instructions on how to release the pressurized fuel. Verify the "Fuel Rail Pressure" in ET is 0 ± 8 MPa (0 ± 1160 psi) prior to servicing the fuel system. Repair: Replace the suspect injector. Refer to the Disassembly and Assembly for the appropriate procedure.

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).