46982 Mercruiser ELBOW (90 DEGREES)

Basic Engine Troubleshooting
SMCS Code: 1000-035Troubleshooting can be difficult. The Troubleshooting Index gives a list of possible problems. To make a repair to a problem, see the possible cause and corrective action on the pages that follow. Also, refer to 3176B & 3406E Electronic Troubleshooting, Form No. SENR5582 (R2900-101 to 121) or 3406E Electronic Troubleshooting, Form No. SENR1073 (R2900-122 & Up).This list of problems, causes and corrections will only give an indication of where a possible problem can be and what repairs are needed.Service personnel may remember similar complaints which were corrected by a previous method of troubleshooting. However, just because the complaint is the same the cause for the complaint can be different.Be sure to get a good description of the problem from the operator and/or the person who owns the machine. What they tell you about the problem can save you time and make the repair job faster and easier.Troubleshooting Problem List
1. Loud Combustion Noise ... 382. Fuel Consumption Too High ... 383. Too Much Black or Gray Smoke ... 394. Too Much White Smoke ... 395. Too Much Blue Smoke ... 396. Engine Has Low Oil Pressure ... 397. Engine Overheating ... 408. Engine Overcooling ... 429. Coolant Leaks Outside of Engine ... 4210. Coolant Leaks at the Overflow Tube ... 4211. Coolant Leakage Inside Engine ... 43Troubleshooting Problems
Problem 1: Loud Combustion NoiseProbable Cause:1. Poor Quality or Water in Fuel. Follow the recommendations given in Special Instruction, SEHS7067, Fuel Recommendations for Caterpillar Diesel Engines. Also, Special Instruction, SEHS6947 has fuel correction factors and tables.2. Wrong Timing Position Sensor Calibration. Refer to 3176B & 3406E Electronic Troubleshooting, Form No. SENR5582 (R2900-101 to 121) or 3406E Electronic Troubleshooting, Form No. SENR1073 (R2900-122 & Up). Problem 2: Fuel Consumption Too HighProbable Cause:1. Consumption Measurement Errors Follow machine high fuel consumption check list:* Distance measured correctly* Fill fuel tank and measured correctly* Comparison to other machines* Different machine or engine specifications* Different operating loads* Different operating modes2. Poor Quality or Water in Fuel. Follow the recommendations given in Special Instruction, SEHS7067, Fuel Recommendations For Caterpillar Diesel Engines. Also, Special Instruction, SEHS6947 has fuel correction factors and tables.3. Fuel System Leaks. Inspect the fuel system for leaks and make repairs or replacements as needed.4. Excess Idle Time. Shut engine off when not in use.5. Brakes Dragging. Repair brakes.6. Fuel and Combustion Noise (knock). Refer to 3176B & 3406E Electronic Troubleshooting, Form No. SENR5582 (R2900-101 to 121) or 3406E Electronic Troubleshooting, Form No. SENR1073 (R2900-122 & Up).7. Wrong Timing Position Sensor Calibration. Refer to 3176B & 3406E Electronic Troubleshooting, Form No. SENR5582 (R2900-101 to 121) or 3406E Electronic Troubleshooting, Form No. SENR1073 (R2900-122 & Up). Problem 3: Too Much Black or Gray SmokeProbable Cause:1. Not Enough Air for Combustion. Check for a plugged air cleaner element or blockage in the air lines. Follow the procedures in the Testing and Adjusting section to check inlet manifold pressure and aftercooler core leakage.2. Wrong Timing Position Sensor Calibration. Refer to 3176B & 3406E Electronic Troubleshooting, Form No. SENR5582 (R2900-101 to 121) or 3406E Electronic Troubleshooting, Form NO. SENR1073 (R2900-122 & Up). Problem 4: Too Much White SmokeProbable Cause:1. Too Much Oil in Engine. Do not put too much oil in the crankcase. If the oil level in the crankcase goes up as the engine is used, check for fuel in the crankcase. Make repairs or replacements to the fuel injection lines and nozzles as needed to keep fuel out of the crankcase.2. Engine Misfires or Runs Rough. Check items listed in Problem No. 3. Refer to 3176B & 3406E Electronic Troubleshooting, Form No. SENR5582 (R2900-101 to 121) or 3406E Electronic Troubleshooting, Form No. SENR1073 (R2900-122 & Up).3. Wrong Timing Position Sensor Calibration. Refer to 3176B & 3406E Electronic Troubleshooting, Form No. SENR5582 (R2900-101 to 121) or 3406E Electronic Troubleshooting, Form No. SENR1073 (R2900-122 & Up).4. Coolant in Combustion System. Coolant in the combustion chamber can cause white smoke. A cracked cylinder head or liner, also a bad cylinder head gasket are possible causes for this condition. Problem 5: Too Much Blue Smoke1. Failed Turbocharger Oil Seal. Check inlet manifold and aftercooler core for oil. Make a repair or replacement of the turbocharger as needed.2. Worn Valve Guides. See the Specifications module for the maximum permissible wear of the valve guides.3. Worn Piston Rings. Worn piston rings and/or cylinder walls can be the cause of blue smoke and can cause a loss of compression. Make a visual inspection of the cylinder walls and piston rings. If necessary, measure the cylinder walls and piston rings. For the cylinder and piston ring specifications, see the Specifications module. High wear at low engine hours is normally caused by dirt coming into the engine with the inlet air. Problem 6: Engine Has Low Oil PressureProbable Cause:1. Low Engine Oil Level. Check engine oil level and fill to proper level.2. Oil Leaks. Check for loose oil filter or oil supply lines, etc.3. Dirty Oil Filter or Cooler Core. Check the operation of bypass valve for the filter. Install new oil filter elements if needed. Clean or install new oil cooler core. Remove dirty oil and fill the engine with clean oil to the correct level.4. Diesel Fuel in Lubricating Oil. Find the place where diesel fuel gets into the lubrication oil. Make repairs as needed. Remove any oil that has diesel fuel in it. Install new oil filters and fill the engine with clean oil to the correct level.5. Too Much Clearance Between Rocker Arm Shaft and Rocker Arms. Check for correct lubrication in valve train compartment. Install new parts as necessary.6. Oil Pump Suction Pipe has a Defect. Replacement of the pipe is needed.7. Relief Valve for Oil Pump Does Not Operate Correctly. Clean valve and housing. Install new parts as necessary.8. Oil Pump Has a Defect. Make a repair or replacement of the oil pump as needed.9. Too Much Clearance Between Camshaft and Camshaft Bearings. Install new camshaft and camshaft bearings if necessary.10. Too Much Clearance Between Crankshaft and