90133-ZW1-003 Honda SCREW (10-32X4") (Honda Code 4900908).

Probable Causes
Oil level
Crankcase breather
Sensor
Connectors and wiring
Worn engine componentsRecommended Actions
Table 1
Troubleshooting Test Steps Values Results
1. Check the Engine Oil Level
Oil Level
Result: The engine oil level is OK.
Proceed to Test Step 2.
Result: The engine oil level is high.
Repair: Troubleshoot the cause of the incorrect oil level.
Proceed to Test Step 2.
2. Check for a Plugged Crankcase Breather
Note: If the engine is running in cold ambient temperatures, check to ensure that the breather tube is not plugged with ice.
Plugged Breather
Result: The crankcase breather is not plugged.
Proceed to Test Step 3.
Result: The crankcase breather is plugged.
Repair: Replace the crankcase breather.
Note: A plugged crankcase breather can cause the crankshaft seal to leak. Sealing of the piston rings can be lost and the increase in crankcase blowby will increase the crankcase pressure.
If the problem is not resolved, proceed to Test Step 3.
3. Check the Crankcase Pressure Sensor
A. Connect Cat® Electronic Technician (ET) to the service tool connector.
B. Turn the keyswitch to ON. Do not start the engine.
C. Remove the oil filler cap.
D. Use Cat ET to monitor the following pressures:
- Crankcase pressure
Sensor
Result: The crankcase pressure is within 0 1 kPa (0 4 inch of H2O) of 0 with the keyswitch in the ON position.
Proceed to Test Step 5.
Result: The crankcase pressure is not within 0 1 kPa (0 4 inch of H2O) of 0 with the keyswitch in the ON position.
Proceed to Test Step 4.
4. Inspect the Electrical Connectors and the Wiring
A. Turn the main disconnect switch to OFF.
B. Thoroughly inspect the connectors. Refer to Troubleshooting, "Electrical Connectors-Inspect" for additional information.
C. Perform a 45 N (10 lb) pull test on the connector wires.
D. Check the harness for abrasions and pinch points.
Connectors and Wiring
Result: The connectors and wiring appear to be OK.
Repair: Replace the sensor.
If the problem is not resolved, proceed to Test Step 5.
Result: There is a problem with the connectors and/or wiring.
Repair: Repair or replace the connectors or wiring. Ensure that all the seals are properly in place and ensure that the connectors are coupled.
If the problem is not resolved, proceed to Test Step 5.
5. Inspect the Engine for Internal Problems
Note: Damaged pistons or rings can cause too much pressure in the crankcase. This condition will cause the engine to run rough. There will be more than the normal quantity of fumes (blowby) entering the OCV system. The OCV system can then more quickly become restricted, causing oil leakage at gaskets and seals that would not normally have leakage. Blowby can also be caused by worn valve guides or by a failed turbocharger seal.
A. To determine whether the piston rings leak, measure the crankcase blowby. Use the following service tools, along with Software License, NETG5044:
- 285-0901 Blowby Tool Gp
- 348-5430 Multi-Tool Gp
Refer to Special Instruction, REHS7857, "Testing for Excessive Cylinder Blowby in 3500 Engines" for additional information.
Damaged or Worn Engine Components
Result: There are worn or damaged engine components.
Repair: Repair or replace the worn or damaged engine 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).