- Engine Oil Pre-lubrication
- Variable Speed Fan Control
- Engine Oil Renewal System
1300 rpm when the engine coolant temperature is below 60° C (140° F). The rpm is gradually reduced to 1000 rpm between 60° C (140° F) and 71° C (160° F). When the temperature is greater than 71° C (160° F), the engine will operate at low idle (700 rpm).
Increasing the low idle speed helps prevent incomplete combustion and overcooling. To
temporarily reduce the elevated idle speed, the operator can release the parking brake or depress the throttle momentarily, and the idle speed will decrease to LOW IDLE for 10 minutes.
Cold Cylinder Cutout: The 3500B engine uses a cold cylinder cutout function to:
- Reduce white exhaust smoke (unburned fuel) after start-up and during extended idling in cold weather
- Minimize the time in Cold Mode - Reduce the use of ether injection.
After the engine is started and the automatic ether injection system has stopped injecting ether, the Engine ECM will cut out one cylinder at a time to determine which cylinders are firing. The ECM will disable some of the cylinders that are not firing.
The ECM can identify a cylinder which is not firing by monitoring the fuel rate and engine speed during a cylinder cutout. The ECM averages the fuel delivery and analyzes the fuel rate change during a cylinder cutout to determine if the cylinder is firing.
Disabling some of the cylinders during Cold Mode operation will cause the engine to run rough until the coolant temperature increases above the Cold Mode temperature. This condition is normal, but the operator should be aware it exists to prevent unnecessary complaints.
Engine Start Function: The Engine Start function is controlled by the Engine ECM and the Transmission/Chassis ECM. The Engine ECM provides signals to the Transmission/Chassis ECM regarding the engine speed and the condition of the engine pre-lubrication system. The Transmission/Chassis ECM will energize the starter relay only when:
- The shift lever is in NEUTRAL.
- The parking brake is ENGAGED.
- The engine speed is zero rpm.
- The engine pre-lubrication cycle is complete or turned OFF.
NOTE: To protect the starter, the starter is disengaged when the engine rpm is above 300 rpm.
Engine Oil Pre-lubrication (attachment): Engine oil pre-lubrication is controlled by the Engine ECM and Transmission/Chassis ECM. The Engine ECM energizes the pre-lubrication pump relay located behind the cab (see Visual No. 53) The relay behind the cab then energizes the pre-lube relay (1) on the front engine mount. The Engine ECM signals the Transmission/
Chassis ECM to crank the engine when:
- Engine oil pressure is 3 kPa (.4 psi) or higher.
- The pre-lubrication pump (2) has run for 17 seconds. (If the system times out after 17 seconds, a pre-lubrication time out fault is logged in the Engine ECM.)
- The engine has been running in the last two minutes.
- Coolant temperature is above 50° C (122° F).
The engine oil pre-lubrication system can be bypassed to allow quick starts. To override the pre-lubrication system, turn the key start switch to the CRANK position for a minimum of two seconds. The Transmission/Chassis ECM will begin the pre-lube cycle. While the pre-lube cycle is active, turn the key start switch to the OFF position. Within 10 seconds, turn the key start switch back to the CRANK position. The Transmission/Chassis ECM will energize the starter relay.
If the engine oil pre-lubrication system is bypassed using the above procedure, the Engine ECM will log a pre-lube override event that requires a factory password to clear.
NOTE: The ECAP and ET can enable or disable the pre-lubrication feature in the Engine ECM.
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Variable Speed Fan Control (attachment): If the engine is equipped with a variable speed fan, the Engine ECM regulates the fan speed. Fan speed varies according to the temperature of the engine. The ECM sends a signal to the variable speed fan control solenoid valve (1) and engine oil pressure engages a clutch as needed to change the speed of the fan.
The jacket water coolant temperature sensor (2) is located in the jacket water temperature regulator (thermostat) housing. The ECM uses the coolant temperature sensor information as the main parameter to control the fan speed. The aftercooler temperature sensor, air conditioner pressure sensor and brake cooling oil temperature sensors are also used as inputs to determine the required fan speed. A speed sensor (not shown) is located behind the fan pulley and informs the ECM of the current fan speed.
The variable speed fan feature can be turned off using the ECAP or ET service tool. Turning off the variable speed fan feature will set the fan speed at MAXIMUM rpm. Disconnecting the air conditioning compressor switch will also signal the ECM to set the fan speed at MAXIMUM rpm (see Visual No. 62).
The turbocharger outlet pressure sensor (3) sends an input signal to the Engine ECM. The ECM compares the value of the turbo outlet pressure sensor with the value of the atmospheric pressure sensor and calculates boost pressure.
INSTRUCTOR NOTE: For more information on the variable speed fan, refer to the Service Manual "Variable Speed Fan Clutch" (Form SENR8603).
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Engine Oil Renewal System (attachment): Located on the right side of the engine are the components of the engine oil renewal system. Engine oil flows from the engine block to the engine oil renewal solenoid valve (arrow). When the solenoid is energized and de-energized, a small amount of oil flows from the engine oil renewal solenoid valve into the fuel line that returns to the fuel tank. The engine oil mixes with the fuel in the tank and flows with the fuel to the EUI injectors to be burned.
If the machine is equipped with the engine oil renewal system, the engine oil filters, the engine oil renewal system filter, the primary fuel filter, and the secondary fuel filters must all be changed at 500 hour intervals. The engine oil should be changed at least once per year or 4000 service meter hours.
Engine oil samples must be taken regularly to ensure that the soot level of the engine oil is in a safe operating range.
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valve. Several parameters must be met before the ECM will allow the injection of oil through the engine oil renewal system. The parameters that must be met are:
- Fuel position is greater than 10.
- Engine rpm is between 1100 and 1850 rpm.
- Jacket water temperature is between 63° C (145° F) and 107° C (225° F).
- Fuel filter differential pressure is less than 140 kPa (20 psi).
- Fuel level is greater than 10%.
- Engine oil level switches are sending a valid signal to the Engine ECM.
- Engine has been running more than five minutes.
The engine oil renewal system can be turned ON or OFF with the ET service tool. The amount of oil injected can also be adjusted by programming the Engine ECM with the ET service tool.
The factory setting shown in the service tool is "0" and is equivalent to a 0.5% oil to fuel ratio.
The ratio can be changed with the service tool from minus 50 (-50) to plus 50 (+50), which is equivalent to 0.25% to 0.75% oil to fuel ratios.
INSTRUCTOR NOTE: For more detailed information on servicing the oil renewal system, refer to the Service Manual Module "Oil Renewal System" (Form RENR2223).
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Shown is a sectional view of the engine oil renewal solenoid valve. When the Engine Slave ECM determines that oil can be injected into the fuel return line, a Pulse Width Modulated (PWM) duty cycle signal is sent to the oil renewal solenoid. The solenoid is turned ON for 1.25 seconds and turned OFF for 1.25 seconds for a total cycle time of 2.5 seconds. How many times the solenoid is turned ON and OFF will determine the volume of oil that is injected. Oil is injected when the solenoid is turned ON and oil is also injected when the solenoid is turned OFF. When the solenoid is turned ON, engine oil flows to the left side of the piston and pushes the piston to the right. The volume of oil that is trapped between the right side of the piston and the check ball compresses the spring and opens the passage to the fuel return line. When the solenoid is turned OFF, engine oil flows to the right side of the piston and pushes the piston to the left. The volume of oil that is trapped between the left side of the piston and the check ball compresses the spring and opens the passage to the fuel return line. The volume of delivery is equal to 3.04 ml/cycle (0.1 oz/cycle).
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