3512C Engine and 785D Off-Highway Truck/Tractors Caterpillar

Probable Causes

• Cold mode

• Starting aids (if applicable)

• Coolant temperature sensor

• Engine speed/timing

• Injectors

• Engine parameters

• Fuel supply

• Component wear

• Cooling system

Recommended Actions

Cold Mode

Excessive white smoke emissions may occur during cold mode operation of the engine. During cold mode operation of the engine, the Electronic Control Module (ECM) may modify the injection timing and the ECM may cut out certain engine cylinders. This will increase startability and this will reduce warm up time. Cold mode is activated whenever the engine coolant temperature falls below a predetermined value. Cold mode remains active until the engine has warmed or a time limit is exceeded.

Starting Aids (If Applicable)

1. If a jacket water heater is installed on your application, check for proper operation of the circuit. Repair the circuit for the jacket water heater, if necessary.

2. If the application has an ether injection system, ensure that the ether canister is not empty or low. Replace the ether canister if the ether canister is empty or low. If an electrical problem with the ether injection system is suspected, refer to Troubleshooting, "Ether Starting Aid - Test".

Coolant Temperature Sensor

Compare the coolant temperature from Caterpillar Electronic Technician (ET) to the coolant temperature that is obtained from the 6V-9130 Temperature Adapter (MULTIMETER). Ensure that the temperature readings are reasonable for the conditions that are present.

Engine Speed/Timing

1. Check the calibration of the engine speed/timing sensor. Refer to Troubleshooting, "Timing - Calibrate".

2. Verify that the timing of the crankshaft and camshaft drive gears are set with the proper orientation. Refer to Disassembly and Assembly for information that is related to the correct gear installation.

Injectors

1. Perform the "Injector Solenoid Test" on Cat ET in order to determine if all of the injector solenoids are being energized by the ECM.

2. Perform the "Cylinder Cutout Test" on Cat ET in order to determine the performance of each cylinder. Refer to Troubleshooting, "Injector Solenoid - Test" for the proper procedure.

Engine Parameters

Verify that the current flash file has been installed and then verify that the correct engine parameters are being used.

Fuel Supply

Check the fuel quality. Low cetane fuel can create white smoke. If necessary, replace the fuel with a higher cetane fuel.

Component Wear

1. Check the valve lash and reset the valve lash, if necessary. Refer to Systems Operation/Testing and Adjusting.

2. Possible causes of low compression are shown in the following list:

   • Faulty piston

   • Faulty piston rings

   • Worn cylinder bores

   • Worn valves

   • Faulty cylinder head gasket

   • Damaged cylinder head

3. Perform all necessary repairs. Ensure that the repairs have eliminated the problem.

Cooling System

Check for an internal coolant leak into the cylinder and/or the exhaust. Refer to Systems Operation/Testing and Adjusting for information on inspecting the cooling system.