This page introduces the possible causes and troubleshooting methods of Caterpillar 325C excavator engine oil pressure low and excessive white smoke or blue smoke

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a. Excessive white or blue smoke The possible causes and solutions are as follows.  

 (1) There is too much lubricating oil in the engine. Drain off excess oil. Find out its source. Fill the engine with an appropriate amount of oil. 

(2) The engine misfires or the engine does not run smoothly. Refer to the "Engine Misfiring or Rough Engine Running" section. 

 (3) Fuel injection timing error. Adjust timing. 

 (4) The valve guide is worn. The cylinder head needs to be repaired. 

 (5) The piston ring is worn. Install new parts if necessary. 

 (6) The turbocharger oil seal is damaged. Check the intake pipe for oil. Repair turbocharger if necessary.  

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b. The possible causes of low engine oil pressure and the troubleshooting methods are as follows. 

 (1) The oil pressure gauge is faulty. Install a new oil pressure gauge. 

 (2) The engine oil filter or oil cooler is dirty. Check the operation of the filter bypass valve. If necessary, install a new oil filter element. Clean the engine oil cooler core or install a new one. Drain the dirty oil in the engine and fill it with clean oil. 

 (3) There is diesel oil in the lubricating oil. Locate the source of diesel leakage into the lubricating oil. Repair if necessary. Drain lubricating oil contaminated with diesel fuel. Install a new oil filter. Fill the engine with clean oil. 

 (4) The gap between the rocker shaft and the rocker arm is too large. Check the lubrication of the valve chamber. Install new parts if necessary. 

 (5) The suction pipe of the oil pump is faulty. The oil pump suction pipe needs to be replaced. 

 (6) Improper operation of the pressure safety valve of the oil pump. Clean valve and housing. Install new parts if necessary. 

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 (7) Oil pump failure. Repair or replace the oil pump if necessary.

  (8) The gap between the crankshaft and the crankshaft bearing is too large. Check crankshaft bearings. Replace with new parts if necessary.

  (9) The clearance between the camshaft and the camshaft bearing is too large. Check the camshaft and camshaft bearings. Replace with new parts if necessary. 

 (10) The intermediate gear bearing clearance is too large. Check the bearings. Replace with new parts if necessary.