CATERPILLAR - TECH TIPS

ENGINE INSPECTIONS:

• Engine Oil Level - Look not just for Low Oil Level, but HIGH OIL LEVEL. Fuel Dilution from failing Fuel Injectors, Cylinder Washout, Etc, can cause High Oil Levels.  

• Fuel and Oil Consumption - Check with Operator to determine if there has been recent increases in Fuel or Oil Consumption, or other changes in engine performance. 

• HEUI FUEL INJECTORS - Older Caterpillar engines use Hydraulic Electronic Unit Injectors, over time the Fuel Injectors and High Pressure Oil Pump wear out, and the Fuel Injectors do not work properly, which can cause cylinder washout, elevated oil levels, and the engine overall running poorly. Erratic Hydraulic Oil Pressure at high pressures (~4,000PSI) will occur when wear is high.  

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• High Pressure Fuel System - Newer Caterpillar engines use a High Pressure Common Rail fuel system. Using Cat ET, test the High Pressure Fuel System to check for internal or external leaks by raising Fuel Rail Pressure and confirming holds at the high pressure over 20,000PSI (worn internal valves in the Fuel Injectors are most commonly the root cause for loss of fuel pressure - requiring new Fuel Injectors and Fuel Connectors to be installed). 

• Oil Leaks - Look closely for any Oil Leaks bleeding through rubber CAC boots. Oil entry into the CAC and Intake is a very common problem due to a failing Twin Turbochargers. This causes Soot/Oil to mix in the intake and cause major engine problems. 

• TURBOCHARGER Damage (Inspect) - Remove the Air Intake Boot to the Turbocharger and inspect the impeller/propeller blades for visible damage. Spin the Turbocharger shaft and inspect for bearing damage and/or play.

• TURBOCHARGER Wear (Test) - Recommend running the Air System Verification Test (ASVT) to determine overall Turbo & Intake health, as it is relatively short test in CAT ET. 

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• DPF REGEN Full Test - Running a DPF Parked REGEN can provide significant info on the DPF (and engine) Performance. Monitor the exhaust temperatures over duration of REGEN and compare to proper running REGEN.  Exhaust Temps at DPF Outlet should reach ~1,000F. Most importantly, monitor the Flame Temperature, which will rise quickly once the Ignition Coil turns on, and diesel fuel is passed through the ARD Head. Ignition will not occur when there are problems with the engine and DPF system (a failed ARD HEAD is most commonly the problem). 

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• ARD FUEL PRESSURE TEST - Both the Pilot Fuel Pressure and Main Fuel Pressure may be monitored by using Cat ET Software. Alternatively, mechanical Fuel Pressure Gages may be used to verify Fuel Pressure at the Pilot and Main Fuel Fittings at the ARD Head. Be aware the pressure fluctuates during the REGEN, to match the correct exhaust temperature. 

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• CGI AIR SUPPLY - The CGI (Clean Gas Injection) to the ARD HEAD may be monitored by using Cat ET. The CGI Solenoid Valve status, and CGI Delta-P can be monitored. If CGI Delta-P is not seen after the CGI Valve opens, more often than not the Delta-P Sensor "Tubing" is clogged, and/or the Venturi Tube itself is clogged. Remove the Delta-P Sensor and Venturi to clean if erratic data found. 

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• DPF REGEN (ARD) Basics - Remember, in order for the DPF REGEN to reach ignition, the system needs (3) items: Fuel, Air, Spark, which occurs at the ARD Head. Separating the (3) sections may make diagnostic more more productive.