Troubleshooting Caterpillar 3612 and 3616 (5)

Troubleshooting Caterpillar 3612 and 3616

Air Starting Motor's Pinion does not Disengage from the Flywheel
Probable Cause
1. High air pressure
Check air supply pressure and the air pressure regulator.
2. Incorrect timing of crank termination
Check the controls of the air starting motor for the correct setting for crank termination.
3. Faulty bearing in air starting motor
Check the condition of the bearings in the air starting motor. Replace the bearings, as required.

Electric Starting Motor does not Turn
Probable Cause
1. Low voltage to starting motor
Check power supply to the starting motor. If necessary, make repairs.
2. The wiring is faulty or the switch is faulty.
If necessary, make repairs or replacement.
3. Starting motor's solenoid is faulty.
Install a new solenoid.
4. The starting motor is faulty.
If necessary, repair the starting motor or replace the starting motor.

High Crankcase Pressure
Probable Cause
1. Engine oil level is too high.
Remove extra oil. Find the source of the extra oil. Put the correct amount of oil in the engine.
2. Restricted crankcase breathers
Check and clean crankcase breather elements and tubes.
3. Seized piston and/or stuck piston rings
Replace piston assembly and cylinder liner.
4. Loose fuel injector
Ensure that all fuel injectors are tight.
5. Faulty turbocharger seal
Replace the turbocharger seal.

Turbocharger Surge
Note: A rapid drop in load will cause the turbocharger to surge.
Probable Cause
1. Insufficient air passage through filters or inlet air piping
Ensure that the filters are sized properly for the engine. Ensure that the air passages are clean and that the air
passages are free of obstructions.
2. The inlet manifold temperature is too high.
Refer to "High Air Inlet Temperature".
3. Partially closed air shutoff
Ensure that the air shutoff is in the open position.
4. Unequal operation between cylinder banks
Ensure that the cylinder banks are operating evenly. Look for any cylinders that are misfiring. This may be the
cause of uneven operation. Refer to "Misfire or Running Rough".
5. Unequal exhaust back pressure between cylinder banks
The maximum allowable differential pressure between the cylinder banks is 0.5 kpa (2.00 inches of H2o).
Ensure that the difference between the back pressures of the cylinder banks is no greater than this limit.
6. Fouled turbocharger compressor or a fouled turbocharger diffuser (air side)
Ensure that the passages are free of debris. Ensure that there is not excessive soot in the passages.
7. Damaged turbocharger compressor or a damaged turbocharger diffuser
Ensure that the components are not damaged. If necessary, replace the components or repair the components.
8. Incorrect turbocharger or associated parts
Ensure that the installed turbocharger has the proper rating. Ensure that the parts that are used are intended for
the turbocharger that is being used.
9. High pressure drop in aftercooler (air side)
Ensure that the pressure drop between the compressor outlet and the intake manifold is not excessive.
10. Fouled turbocharger nozzle (turbine side)
On engines that use heavy fuel oil, ensure that the proper water wash intervals are followed.
11. Excessive turbulence at the air inlet for the turbocharger
Ensure that transitions within the ducting to the air inlet for the turbocharger are not too close to the
turbocharger. Use a Caterpillar supplied air inlet elbow or follow the guidelines that are given in the
"Application and Installation Guide".
Note: Inlet air piping that is common to two turbochargers should receive special attention.
12. Excessive back pressure
On engines that use heavy fuel oil and high overlap camshafts, ensure that there is not excessive back pressure.
13. Low inlet air temperature to turbocharger
Ambient air temperature that is below 0 °C (32 °F) should be noted in the rating request. This will allow proper
selection of a turbocharger. Contact your local Caterpillar dealer.
14. Too little valve lash (unlikely cause)
Adjust the valve lash. Refer to System Operation/Testing and Adjusting, "Valve Lash and Valve Bridge
Adjustment".
15. Damage to valve train components
Inspect all of the following valve train components:
Valves
Springs
Camshafts
Lifters
Rocker arms
Pushrods
Check for worn parts or damaged parts. Replace worn parts or damaged parts, as required.
16. Incorrect camshaft installation
Ensure that the camshafts are installed correctly. Refer to System Operation/Testing and Adjusting, "Fuel
System".
17. High load operation at low engine speed
Ensure that engine speed is not below 85 percent rated speed on engines that are not used as gensets during high load operation.

Low Boost Pressure
Probable Cause
1. Insufficient air passage through filters or inlet air piping
When the filters and the piping are clean, the pressure drop must not exceed 1.5 kpa (5.00 inches of H2O). This
pressure drop is measured between the filter inlets and the turbocharger inlet.
When the filters and the piping are dirty, the pressure drop must not exceed 3.75 kpa (15 inches of H2O). This
pressure drop is measured between the filter inlet and the turbocharger inlet.
2. Inlet air leakage
Check the following locations and the associated piping for air leakage. If necessary, make corrections.
O-ring seals between the compressor and the aftercooler
Air inlet shutoff
Plugged sections
Gaskets within aftercooler
Plenum
3. Excessive exhaust restriction
Ensure that the pressure difference between the outlet of the turbocharger and the atmosphere is less than 2.5kpa (10 inches of H2O).
4. Leakage of the exhaust piping
Ensure that there are no exhaust leaks. If necessary, make the proper repairs.
5. Dirty turbocharger
Clean the turbocharger.
6. Damaged turbine nozzle or damaged turbine blades
Ensure that the components of the turbine are not damaged.
7. Incorrect turbocharger or associated parts
Ensure that the installed turbocharger has the proper rating. Ensure that the parts that are used are intended for
the turbocharger that is being used.
8. The turbocharger bearings are damaged or the turbocharger bearings are not functioning correctly.
Ensure that the bearings are operating correctly and that the bearings are not causing excessive drag.
9. Damaged turbocharger compressor or turbocharger diffuser
Ensure that the components are not damaged. If necessary, replace the components or repair the components.
10. Partially closed air shutoff
Ensure that the air shutoff is in the open position.
11. The timing is advanced too far.
This will be only a minor influence. Refer to System Operation/Testing and Adjusting, "Camshaft Timing".
12. High pressure drop in aftercooler (air side)
Ensure that the pressure drop between the compressor outlet and the intake manifold is not excessive.
13. Wrong camshaft (high overlap camshaft)
Ensure that the correct camshafts are installed in the engine.
14. Incorrect valve lash (minor influence)
Adjust the valve lash. Refer to System Operation/Testing and Adjusting, "Valve Lash and Valve Bridge
Adjustment".
15. High ambient temperature
Inlet manifold pressure decreases approximately 0.3 percent for every 1 °C increase of the temperature of the air
to the turbocharger compressor.

High Boost Pressure
Probable Cause
1. Incorrect fuel setting
Make adjustment to timing. Refer to System Operation/Testing and Adjusting, "Fuel Setting".
2. Turbine nozzle ring is clogged with carbon.
Clean the ring.
3. Excessive engine load
Lighten the load on the engine.

Low Efficiency
Probable Cause
1. Ineffective aftercooler
Check temperature of inlet and outlet coolant supply. Remove any external restrictions or internal restrictions.
2. Late fuel injection timing
Make adjustment to timing. Refer to System Operation/Testing And Adjusting, "Fuel Timing".
3. High ambient temperature
Inlet manifold pressure decreases approximately 0.3 percent for every 1 °C increase of the temperature of the air
to the turbocharger compressor.
4. Excessive back pressure
On engines that use heavy fuel oil and high overlap camshafts, ensure that there is not excessive back pressure.
5. Engine misfiring
Refer to "Misfire or Running Rough".
6. A damaged turbine nozzle and turbine blades
Ensure that the components of the turbine are not damaged.
7. A worn turbine nozzle and turbine blades
Ensure that the components of the turbine are not worn.
8. Generator's efficiency is low.
An engine may appear to be operating with low efficiency. Ensure that the driven generator is operating at the
correct efficiency.
9. Improper conditions of fuel
Ensure that the following fuel requirements are being met.
Temperature
Heating value
Pressure
Api gravity
Governor limiting rack setting
Refer to Caterpillar 3600 Series Diesel Engine Fluids Recommendations For Lubricants, Fuels, and Coolants,SEBU7003.

Turbocharger Vibration
Probable Cause
1. Severe unbalance of the rotor due to dirt or damaged turbine blades
Rebalance the rotor assembly.
2. Bent rotor shaft
Inspect the shaft. Replace the shaft if it is necessary.
3. Worn bearings
Inspect the bearings. Replace the bearings if it is necessary.
4. Incorrectly assembled bearings
Inspect the bearings. Replace the bearings if it is necessary.

Engine Starts but the Turbocharger does not Turn
Probable cause
1. Debris is trapped between the turbine blade tips and the shroud ring.
Clean and eliminate the cause of the entrance of the debris.
2. Bearing failure
Inspect the bearings. Replace the bearings if it is necessary.

CAT SENR3593 - 3612 and 3616 Engines

Sumber : manuals book Caterpillar