ELBOW ASSEM. 2P0927 - Caterpillar

Note: This is not an electronic system fault.Refer to Systems Operation, Testing and Adjusting for information on determining the cause of this condition.Probable Causes
Engine supports
Low compression (cylinder pressure)
Fuel injection nozzles
Malfunctioning individual cylinderRecommended Actions
Engine Supports
Start the engine and run the engine through the speed range. Check for any of the following conditions:
Loose engine supports
Loose mounting brackets or broken mounting brackets
Loose bolts
Omitted bolts
Make all necessary repairs. Ensure that the repairs have eliminated the fault. If the vibration is still present, proceed to "Low Compression (cylinder pressure)". Low Compression (cylinder pressure)
Remove the fuel injection nozzles from the cylinder head. Refer to Disassembly and Assembly, "Fuel Injection Nozzles - Remove".
Perform a compression test on each cylinder. Refer to Systems Operation, Testing and Adjusting, "Compression - Test".
If necessary, investigate the cause of low compression. Examples of low compression are shown in the following list:
Loose glow plugs (if equipped)
Mechanical problem
Faulty piston rings
Worn cylinder bores
Worn valves
Faulty cylinder head gasket
Damaged cylinder head
If the vibration has not been eliminated, proceed to "Fuel Injection Nozzles". Fuel Injection Nozzles
Remove the fuel injection nozzles from the cylinder head. Refer to Disassembly and Assembly, "Fuel Injection Nozzles - Remove".
Visually inspect the fuel injection nozzles. If there is a suspected fault, replace the faulty fuel injection nozzle.
Install the fuel injection nozzles. Refer to Disassembly and Assembly, "Fuel Injection Nozzles - Install".
Ensure that the repairs have eliminated the fault.
If the vibration has not been eliminated, proceed to "Malfunctioning Individual Cylinder". Malfunctioning Individual Cylinder
With the engine speed at a fast idle, loosen the high pressure fuel line to the fuel injection nozzle of number 1 cylinder. Note if there is any reduction in engine speed. Tighten the high pressure fuel line to the fuel injection nozzle.
Individually repeat this procedure for each fuel injection nozzle. If there is no reduction in the engine speed, investigate the cause of the malfunction.