DPF Troubleshooting Guide
| DPF Troubleshooting Guide | |||
|---|---|---|---|
| Symptoms | Cause of Symptom | Cause of Failure | Resolution |
| Exhaust Smoke | Broken/Cracked Filter Substrate | Excess Vibration/Impact from careless handling. | Replace Substrate. Tighten and lock all mounting bolts. |
| Thermal shock from runaway regeneration due to excessive soot buildup prior to regeneration. | Ensure that mounting is correct and vibration minimal. Ensure that exhaust temp is 240° C (464° F) or greater 40% of run time. |
||
| Water leakage from improper drainage or stuck open rain cap causing thermal shock, cracking, or loosening of filter substrate. | Repair rain cap, ensure proper water drainage. Ensure that there is a 1/4 inch drain hole in the bottom of the exhaust end cap. Replace the filter unit | ||
| Exhaust Smoke | Excessive vibration/DPF Failure-Cracking | Cracking can be caused by loose/improper mounting (excessive vibration), external impact. | Properly tighten/lock mounting bolts. Inspect mounting for cracking or improper installation and so on, Follow published DPF mounting guidelines. |
| DPF Unit Rattling (Internal) | Loose Filter Substrate | Internal retaining mat damage due to water exposure | Replace Filter Module-cannot be repaired. Ensure proper rain cap operation. Ensure proper water/condensate drainage by drilling a 1/4 inch hole in the lowest part of the exhaust outlet end cap. |
| DPF Assembly Rattling | Loose Mounting Hardware | Improperly locked/torqued nuts, bolts, or clamps | Tighten and torque all fasteners on mounting assembly. Ensure that all nuts and bolts are properly torqued and are locked with lock washers, castle nuts, or thread locking compound as appropriate. Check and ensure that all band or other clamps are functioning properly. Use torques specified in the DPF Catalog or in Torque Specifications, SENR3130 (for mounting hardware). |
| Oil In Filter Substrate | Turbocharger Bearing Oil Leak | Oil starvation of turbocharger bearing. | Clean and clear oil supply line to turbocharger. Repair Turbocharger. Attempt to thermally regenerate and clean DPF substrate-may not be successful due to excess oil and potential thermal shock during regeneration. Replace substrate if regeneration unsuccessful. |
| Habitual shutdowns using the emergency stop button depriving the turbocharger of oil if Accumulator not present or not functioning | Educate the operator. Repair Turbocharger. Repair Oil Accumulator assembly if present. Attempt to thermally regenerate and clean DPF substrate-may not be successful due to excess oil and potential thermal shock during regeneration. Replace substrate if regeneration unsuccessful. | ||
| Partial blockage of the turbocharger oil line | Ensure that turbocharger oil line is clear and clean. Repair Turbocharger. Attempt to thermally regenerate and clean DPF substrate-may not be successful due to excess oil and potential thermal shock during regeneration. Reinstall substrate if regeneration successful. If Regeneration is unsuccessful, replace the filter unit. | ||
| Inadequate coolant flow to turbocharger. | Flush cooling system. Ensure that coolant line to turbocharger is clean and clear. Repair Turbocharger. Attempt to thermally regenerate and clean DPF substrate-may not be successful due to excess oil and potential thermal shock during regeneration. Reinstall substrate if regeneration successful. If Regeneration is unsuccessful, replace the filter unit. | ||
| Excessive Back Pressure/Low Power | Filter Clogging with Soot or Ash | Excessively light-duty cycle resulting in inadequate regeneration. | Remove filter module (clean/replace). Increase duty cycle. Monitor exhaust temp. Must be 240° C (464° F) or greater 40% of the time at the DPF inlet. |
| Excessive oil consumption. | Measure oil consumption (use low ash oil). Determine and correct cause of excessive oil consumption. | ||
| Oil ash content too high. | Drain crankcase, fill with Caterpillar approved Low Ash Diesel Engine Oil | ||
| Improper fuel (ULSD required), or lube oil blended with fuel which will cause excessive filter ash buildup. | Purge fuel system of high sulfur fuel and refill with Ultra Low Sulfur Diesel Fuel. Fuel sulfur content is 15 ppm not to exceed 30 ppm. Using diesel fuel that has been blended with lubrication oil will cause rapid DPF failure and will void the DPF warranty. | ||
| Undersized DPF or the whole DPF unit installed backward | Check DPF sizing and orientation. If undersized replace with the proper unit. If the unit is installed backward clean and reinstall properly with the catalyst module closest to Turbocharger. Assure proper orientation of the flow arrow on DPF Module. | ||
| Runaway regeneration causing Melting of Filter Substrate | Melting caused by runaway regeneration from excessive light-duty soot build-up followed by heavy-duty cycle. | Melting-Replace heat damaged parts. DPF inlet temp must be at least 240° C (464° F) for at least 40% of runtime. Clogging-Conform to above and clean DPF at recommended intervals. |
|
| No regeneration | Clogging excessive light-duty use | Monitor the duty cycle and DPF inlet temp which must be at least 240° C (464° F) for at least 40% of runtime. Clogging-Conform to above and clean DPF at recommended intervals. |
|
| Improper cleaning intervals | Failure to observe the proper cleaning interval. | Remove the filter module, thermally regenerate, and clean ash from DPF. Reinstall the filter module. | |
| Monitoring System malfunctions and alarm displays | Refer to Table 3 and the “Diagnostic Module Troubleshooting” section. | ||
| Remote Panel warning lights | |||
| Monitoring System malfunctions, wiring, installation, or programming | |||
Configuration Information
| “Over-Temp” | ||
|---|---|---|
| Inlet Over Temperature Alarm | ||
| Condition | Expected Value | |
| Enable Alarm | Yes | |
| Log Alarm Transitions | Yes | |
| Active Output During Alarm | Output 1 = Red | |
| Output function | ON only during alarm | |
| Assert Alarm | Above 650° C (1202° F) |
|
| Hysteresis | 20° C (68° F) | |
| Upon Over Temperature extend alarm for 60 seconds | ||
| “Over-Pres” | ||
|---|---|---|
| Over Pressure Warning | ||
| Condition | Expected Value | |
| Enable Alarm | Yes | |
| Log Alarm Transitions | Yes | |
| Active Output During Alarm | Output 1 = Red | |
| Output Function | ON only during alarm | |
| Assert Alarm when the measured pressure exceeds 7 In Hg for 5% of the time during a 60 minute measurement interval | ||
| Over Pressure Alarm | ||
| Condition | Expected Value | |
| Enable Alarm | Yes | |
| Log Alarm Transitions | Yes | |
| Active Output During Alarm | Output 2 = Yellow | |
| Output Function | Latched ON upon alarm | |
| Assert alarm when the measured pressure exceeds 8 In Hg for 5% of the time during a 60 minute measurement interval | ||
| TC-Fail (1) | ||
|---|---|---|
| Open Thermocouple Detect | ||
| Condition | Expected Value | |
| Enable Alarm | Yes | |
| Log Alarm Transitions | Yes | |
| Output During Alarm | Output 1 = Red | |
| Output Function | Latched ON upon alarm | |
| Assert alarm if measured temperature is above 1000° C (1832° F) |
||
| Shorted Thermocouple Detect | ||
| Condition | Expected Value | |
| Enable Alarm | Yes | |
| Log Alarm Transitions | Yes | |
| Output During Alarm | Output 1 = Red | |
| Output Function | Latched ON upon alarm | |
| Assert alarm if pressure is greater than 1 In Hg for 10 minutes and measured temperature does not exceed 120° C (248° F) |
||
| ( 1 ) | Output selection applies to both open and shorted alarms |
| Logging Strategy | |
|---|---|
| Memory Utilization | Rotary Memory |
| Logging Threshold | 100° C (212° F) |
| Record Interval | 10 minutes |
| Pressure Sensor Fail | ||
|---|---|---|
| No Change Alarm | ||
| Condition | Expected Value | |
| Enable Alarm | Yes | |
| Log Alarm Transitions | Yes | |
| Active Outputs During Alarm | Output 1 = Red | |
| Output Function | Latched ON upon Alarm | |
| Assert alarm if exhaust temperature is above 250° C (482° F) for 10 minutes and the pressure does not change by at least 0.25 In Hg |
||
| Negative Pressure Alarm | ||
| Condition | Expected Value | |
| Enable Alarm | Yes | |
| Log Alarm Transitions | Yes | |
| Active Output During Alarm | Output 1 = Red | |
| Output Function | Latched ON during alarm | |
| Assert Alarm if temperature is above 200° C (392° F) for 10 minutes and the pressure is less than −1 In Hg |
||
·