IDLER ASSEM. 9H8489 - Caterpillar

Use this procedure to troubleshoot the temperature ratio of coolant to oil. Also, use this procedure if one of the following event codes is active or logged.
Table 1
J1939 Code and Description Comments
4243-0
Engine Oil to Coolant Differential Temperature : High - most severe (3) The engine oil temperature is too high or the engine coolant temperature is too low. The differential between the engine oil temperature and the engine coolant temperature has exceeded the trip point and the delay time has expired.
The code is logged.
4243-15
Engine Oil to Coolant Differential Temperature : High - least severe (1) The engine oil temperature is too high or the engine coolant temperature is too low. The differential between the engine oil temperature and the engine coolant temperature has exceeded the trip point and the delay time has expired.
The code is logged.
4243-16
Engine Oil to Coolant Differential Temperature : High - moderate severity (2) The engine oil temperature is too high or the engine coolant temperature is too low. The differential between the engine oil temperature and the engine coolant temperature has exceeded the trip point and the delay time has expired.
The code is logged. Note: The cylinder liner and the piston assembly can be damaged by this condition.Probable Causes
Codes
Temperatures
Control valves
Sensor
Temperature regulatorsRecommended Actions
Table 2
Troubleshooting Test Step Value Result
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 the Oil Temperature and the Coolant Temperature
A. Observe the temperature of the engine oil and the engine coolant on the control panel display.
Temperatures
Result : The oil and coolant temperatures are OK.
Proceed to Test Step 3.
Result: The oil and/or coolant temperature are NOT OK.
Repair: If the oil temperature is high, refer to Troubleshooting, "Oil Temperature Is High".
If the temperature of the coolant is low, refer to Troubleshooting, "Coolant Temperature Is Low".
If the problem is not resolved, proceed to Test Step 3.
3. Check the Control Valves for the Coolant System
Control Valves
Result: The control valves are OK.
Proceed to Test Step 4.
Result: The control valves are NOT OK.
Repair: Repair or replace the temperature sensors.
If the problem is not resolved, proceed to Test Step 4.
4. Check the Oil and Coolant Temperature Sensors
A. Connect Cat ET.
B. Use Cat ET to monitor the following temperature:
- Oil temperature
- Coolant temperature
Note: The temperatures should rise steadily as the engine is warmed.
C. Ensure that the temperatures are reasonable.
D. Reference the readings to other temperature indicators when possible.
E. Compare the measured temperatures to the readings on the control panel's display.
Sensors
Result: The oil and coolant temperature sensors are OK.
Proceed to Test Step 5.
Result: The oil and/or coolant temperature sensors are NOT OK.
Repair: Repair or replace the temperature sensors.
If the problem is not resolved, proceed to Test Step 5.
5. Check the Water Temperature Regulators
Note: The water temperature regulators should not begin to open until jacket water reaches opening