3408C, 3412C and 3412D High Performance Marine Engines Caterpillar

Introduction

Troubleshooting can be difficult. The following pages contain a list of possible problems. In order to make a repair to a problem, refer to the cause and the correction of the problem.

The list on the following pages will provide the following information:

• known problems

• probable causes of known problems

• repairs in order to correct known problems

Normally, additional repair work is needed beyond the recommendation in the list.

Remember that a problem is not normally caused by only one part. The problem's cause can be related to problems with other parts. This list does not include all possible problems and corrections. The service technician must find the problem and the problem's source. After the problem's source is determined, the service technician can make the necessary repairs.

Troubleshooting Problem List

1. The Engine Crankshaft Will Not Turn When The Start Switch Is On.

2. The Engine Will Not Start.

3. The Engine Is Misfiring Or The Engine Is Running Rough.

4. The Engine Stalls At Low RPM.

5. The Engine Has Sudden Changes In Engine RPM.

6. The Dashpot Governor Corrects The Speed Of The Engine Slowly. The Engine Changes Speeds Constantly.

7. The Engine Does Not Have Enough Power.

8. The Engine Has Too Much Vibration.

9. The Engine Has A Loud Combustion Noise (Knock).

10. The Engine Has a Valve Train Noise (Clicking).

11. Oil Is In The Cooling System.

12. Mechanical Noise (Knock) Is In The Engine.

13. Fuel Consumption Is Too High.

14. A Loud Noise Is In The Valve Train.

15. Too Much Valve Lash Is Present.

16. The Valve Rotocoil Or The Spring Lock Is Free.

17. Oil Is At The Exhaust.

18. Little Valve Lash Or No Valve Lash Is Present.

19. The Engine Has Early Wear.

20. Coolant Is In The Lubrication Oil.

21. Too Much Black Smoke Or Gray Smoke Is Present.

22. Too Much White Smoke Or Blue Smoke Is Present.

23. The Engine Has Low Oil Pressure.

24. The Engine Uses Too Much Lubrication Oil.

25. The Engine Coolant Is Too Hot.

26. The Exhaust Temperature Is Too High.

27. The Starting Motor Does Not Turn.

28. The Alternator Provides No Charge.

29. The Alternator Charge Rate Is Low. The Alternator Charge Rate Is Not Regular.

30. The Alternator Charge Rate Is Too High.

31. The Alternator Has Noise.

32. The Rack Solenoid Does Not Stop The Engine.

Troubleshooting Problems

Problem 1

The Engine Crankshaft Will Not Turn When The Start Switch Is On.

Probable Cause

1. Low Output Of The Battery

   Refer to "Problem 27".

2. Faulty Wires Or Faulty Switches

   Refer to "Problem 27".

3. Faulty Starter Motor Solenoid

   Refer to "Problem 27".

4. Problem With The Starting Motor

   Refer to "Problem 27".

5. An Internal Problem Prevents The Turning Of The Engine Crankshaft.

   If the crankshaft cannot be turned after disconnecting the driven equipment, inspect the cylinders for fluid while the crankshaft is being turned. If fluid in the cylinders is not the problem, the engine must be disassembled. After disassembling the engine, inspect the engine for other internal problems. Possible internal problems include the following conditions:

   • bearing seizure

   • piston seizure

   • valve and piston contact

Problem 2

The Engine Will Not Start.

Probable Cause

1. A Slow Turning Starter Motor

   Refer to "Problem 27" and refer to "Problem 28".

2. Dirty Fuel Filter

   Install a new fuel filter.

3. Dirty Fuel Line Or Broken Fuel Line

   Clean the fuel lines or install new fuel lines, as required.

4. Fuel Transfer Pump

   At the starting rpm, the minimum fuel pressure from the fuel transfer pump must be 35 kPa (5 psi). Change the fuel filter element if the fuel pressure is less than 35 kPa (5 psi). Look for air in the fuel system. Install a new fuel transfer pump if the fuel pressure is still low.

5. No Fuel To Cylinders

   Put fuel in the tank. Remove the air and/or remove the low quality fuel from the fuel system (prime).

6. Low Quality Fuel

   Remove the fuel from the fuel tank. Install a new fuel filter element. Fill the fuel tank with a good grade of clean fuel.

7. Wrong Fuel Injection Timing

   Make adjustment to timing. Refer to Testing And Adjusting, "Fuel System".

8. Defect In the Shutoff Solenoid

   The solenoid must get electricity to stop the engine. Operate the control for the shutoff solenoid. Listen to make sure that the solenoid makes a noise (clicking sound). If this sound can be heard and the engine will not start, remove the shutoff solenoid. Try and start the engine. If the engine starts, the shutoff solenoid is bad. Replace the shutoff solenoid.

Problem 3

The Engine Is Misfiring Or The Engine Is Running Rough.

Probable Cause

1. Low Fuel Pressure

   The fuel pressure at the outlet of the fuel filter housing must be a minimum of 230 ± 35 kPa (33 ± 5 psi) at full load speed. If fuel pressure is lower than 140 kPa (20 psi), check the following items:

   • plugged fuel filters

   • fuel transfer pump

   Make sure that there is fuel in the fuel tank. Look for leaks or bends in the fuel line between the fuel tank and the fuel transfer pump. Look for air in the fuel system. Also look for a faulty return fuel pressure regulating valve.

2. Air In Fuel System

   Find the air leak in the fuel system and correct the air leak. If there is air in the fuel system, the air generally enters the fuel system on the suction side of the fuel transfer pump.

3. Leakage Or Breakage In Fuel Line Between Fuel Manifold And Cylinder Head

   Install a new fuel line.

4. Wrong Valve Clearance

   Make an adjustment to the valve clearance. Refer to Testing And Adjusting, "Air Inlet And Exhaust System".

5. Defect In Fuel Injector

   Run the engine at a rpm that causes the engine to misfire or run the engine at a rpm that causes the engine to run rough. Loosen a fuel injection line nut at the valve cover base for each cylinder. Loosen a fuel injection line nut one at a time. Locate the cylinder that does not change the operation of the engine. Test the injection pump. Test the fuel injection nozzle for that cylinder. Install new parts, as required.

6. Wrong Fuel Injection Timing

   Make adjustment to timing. Refer to Testing And Adjusting, "Fuel System".

7. Bent Pushrod Or Broken Pushrod

   Make a replacement of pushrod, if necessary.

8. Fuel Has Cloud Point Higher Than Atmospheric Temperature. Cloud Point Is The Temperature When Wax Is Formed In The Fuel.

   Drain the fuel tank, fuel lines and fuel manifolds. Change the fuel filter. Fill the tank with fuel that has the correct cloud point. Remove the air from the system with the priming pump.

Problem 4

The Engine Stalls At Low RPM.

Probable Cause

1. Low Fuel Pressure

   The fuel pressure at the outlet of the fuel filter housing must be a minimum of 230 ± 35 kPa (33 ± 5 psi) at full load speed. If fuel pressure is lower than 140 kPa (20 psi), check the following items:

   • plugged fuel filters

   • fuel transfer pump

   Make sure that there is fuel in the fuel tank. Look for leaks or bends in the fuel line between the fuel tank and the fuel transfer pump. Look for air in the fuel system. Also look for a faulty return fuel pressure regulating valve.

2. Low Engine Idle RPM

   Make adjustment to the governor. Ensure that the idle rpm setting matches the rpm that is listed in the "Fuel Setting Information".

3. Defect In Fuel Injection Nozzle

   Install a new fuel injection nozzle.

4. Engine Accessories

   Check the engine accessories for damage. Check the engine accessories for correct adjustments. If necessary, disconnect the accessories and test the engine.

5. Defect In Fuel Injection Pump

   Install new part.

Problem 5

The Engine Has Sudden Changes In Engine Speed (RPM).

Probable Cause

1. Failure Of The Governor Or Failure Of The Fuel Injection Pump

   Look for defects in the following parts:

   • damaged springs or broken springs

   • damaged linkage

   • damaged parts

   Remove the governor. Check for free travel of the fuel racks. Make sure that the fuel injection pumps are installed correctly. Check for the correct governor spring. If necessary, install new parts.

Problem 6

The Dashpot Governor Corrects The Speed Of The Engine Slowly. The Engine Changes Speeds Constantly.

Probable Cause

1. Wrong Adjustment Of Dashpot Governor

   Make the correct adjustment. Refer to Testing And Adjusting, "Fuel System".

Problem 7

The Engine Does Not Have Enough Power.

Probable Cause

1. Low Quality Fuel Or Water In Fuel

   Remove the fuel from the fuel tank. Install new fuel filters. Put a good grade of clean fuel in the fuel tank.

2. Low Fuel Pressure

   The fuel pressure at the outlet of the fuel filter housing must be a minimum of 230 ± 35 kPa (33 ± 5 psi) at full load speed. If fuel pressure is lower than 140 kPa (20 psi), install new fuel filter elements. If the fuel pressure is still low, check the fuel transfer pump.

   Make sure that there is fuel in the fuel tank. Look for leaks or bends in the fuel line between the fuel tank and the fuel transfer pump. Look for air in the fuel system. Also look for a faulty return fuel pressure regulating valve.

3. Leaks In Air Inlet System

   Check the pressure in the air inlet manifold. Look for restrictions in the air cleaner.

4. Governor And Fuel Control Linkage

   Ensure that the governor is moving the fuel control linkage against the fuel setting stop. Make adjustment in order to get the full travel of the linkage. Install new parts for those parts that have damage or defects.

5. Wrong Valve Clearance

   Make an adjustment to the valve clearance. Refer to Testing And Adjusting, "Air Inlet And Exhaust System".

6. Defect In Fuel Injector

   Run the engine at a rpm that causes the engine to misfire or run the engine at a rpm that causes the engine to run rough. Loosen a fuel injection line nut at the valve cover base for each cylinder. Loosen a fuel injection line nut one at a time. Locate the cylinder that does not change the operation of the engine. Test the injection pump. Test the fuel injection nozzle for that cylinder. Install new parts, as required.

7. Wrong Fuel Injection Timing

   Make adjustment to timing. Refer to Testing And Adjusting, "Fuel System".

8. Incorrect Fuel Setting

   Make adjustment to timing. Refer to Testing And Adjusting, "Fuel System".

9. Defect In Aftercooler

   Check temperature of inlet and outlet coolant supply. Remove any external restrictions or internal restrictions.

10. Carbon Deposits On Turbocharger Or Other Causes Of Friction

    Inspect the turbocharger. Repair the turbocharger, if necessary.

Problem 8

The Engine Has Too Much Vibration.

Probable Cause

1. Loose Vibration Damper Or Loose Pulley

   Inspect the vibration damper for damage. Inspect the pulley for damage. Tighten the bolts, if necessary. Tighten the nuts, if necessary.

2. Faulty Vibration Damper Or Faulty Pulley

   Install a new vibration damper. Install a new pulley.

3. Engine Supports Are Loose or Faulty.

   Tighten all mounting bolts. Install new components, if necessary.

4. The Engine Is Misfiring Or The Engine Is Running Rough.

   Refer to "Problem 3".

5. Fan Blade Is Not In Balance.

   Loosen the fan drive belts or remove the fan drive belts. Operate the engine for a short time at the rpm that caused the vibration. If vibration is not still present, replace the fan assembly.

Problem 9

The Engine Has A Loud Combustion Noise (Knock).

Probable Cause

1. Low Quality Fuel

   Remove the fuel from the fuel tank. Install a new fuel filter element. Put a good grade of clean fuel in the tank.

2. Defect In Fuel Injector

   Install a new fuel injector.

3. Defect In Injection Pump

   Install a new fuel injection pump.

4. Wrong Fuel Injection Timing

   Make adjustment to timing. Refer to Testing And Adjusting, "Fuel System".

Problem 10

The Engine Has A Valve Train Noise (Clicking).

Probable Cause

1. Damage To Valve Train Components

   Inspect all of the following valve train components:

   • valves

   • springs

   • camshaft

   • lifters

   • rocker arms

   • pushrods

   Check for worn parts or damaged parts. Replace worn parts or damaged parts, as required.

2. Not Enough Lubrication

   Check the lubrication in the valve compartment. There must be a strong flow of oil at engine high rpm. There must be a small flow of oil at low rpm. Oil passages must be clean. The oil passages that send the oil to the cylinder head are particularly important.

3. Too Much Valve Clearance

   Make an adjustment to the valve clearance. Refer to Testing And Adjusting, "Air Inlet And Exhaust System".

Problem 11

Oil Is In The Cooling System.

Probable Cause

1. Defect In Core Of Engine Oil Cooler

   Inspect each engine oil cooler. Repair any faulty oil cooler or replace any faulty oil cooler, as required.

2. Defect In Spacer Plate Gasket

   Install a new spacer plate gasket.

3. Failure Of Cylinder Head Gasket

   Check the cylinder liner projection. Install a new head gasket.

Problem 12

Mechanical Noise (Knock) Is In The Engine.

Probable Cause

1. Failure Of Bearing For Connecting Rod

   Inspect the bearings for the connecting rods and the bearing surfaces (journals) on the crankshaft. Install new parts, as required.

2. Damaged Timing Gears

   Install new parts, as required.

3. Damaged Crankshaft

   Replace the crankshaft.

4. Defect In Accessory Equipment

   Repair the faulty components or install new components.

Problem 13

Fuel Consumption Is Too High.

Probable Cause

1. Fuel System Leaks

   Tighten the parts at points of leakage. Replace the parts.

2. Fuel And Combustion Noise (Knock)

   Refer to "Problem 3" and "Problem 12".

3. Wrong Fuel Injection Timing

   Make adjustment to timing. Refer to Testing And Adjusting, "Fuel System".

Problem 14

A Loud Noise Is In The Valve Train.

Probable Cause

1. Damage To Valve Springs

   Make a replacement of the damaged parts.

2. Damage To Camshaft

   Make a replacement of the damaged parts. Clean the engine thoroughly. If a replacement of the camshaft is made, new valve lifters are also required.

3. Damage To Valve Lifter

   Make a replacement of the damaged parts. Clean the engine thoroughly. Inspect the camshaft cams (lobes) for damage. Inspect the valves that do not move freely. Make an adjustment to the valve clearance. Refer to Testing And Adjusting, "Air Inlet And Exhaust System".

4. Damage To Bridges For Valves Or Damage To Bridge Dowel

   Make a replacement of the damaged parts. Make an adjustment to the bridges, as required.

Problem 15

Too Much Valve Lash Is Present.

Probable Cause

1. Not Enough Lubrication

   Check the lubrication in the valve compartment. There must be a strong flow of oil at engine high rpm. There must be a small flow of oil at low rpm. Oil passages must be clean. The oil passages that send the oil to the cylinder head are particularly important.

2. Worn Rocker Arm

   If the face of the rocker arm that makes contact with the valve bridge has too much wear, install new parts or rocker arms. Make adjustment to valve lash. Refer to Testing And Adjusting, "Air Inlet And Exhaust System".

3. Worn Valve Bridges

   Make an adjustment or replacement, as required.

4. Worn Valve Stem

   If the end of the valve stem has too much wear, install new valves. Make adjustment to valve lash. Refer to Testing And Adjusting, "Air Inlet And Exhaust System".

5. Worn Pushrods

   If the pushrods have too much wear, install new pushrods. Make adjustment to valve lash. Refer to Testing And Adjusting, "Air Inlet And Exhaust System".

6. Broken Valve Lifters Or Worn Valve Lifters

   Install new valve lifters. Check the camshaft for wear. Check for free movement of valves or bent valve stem. Clean the engine thoroughly. Make adjustment to valve lash. Refer to Testing And Adjusting, "Air Inlet And Exhaust System".

7. Worn Camshaft

   Check valve lash. Check for wear on camshaft lobes. Check for free movement of valves or bent valve stems. Install a new camshaft. Install new valve lifters. Make adjustment to valve lash. Refer to Testing And Adjusting, "Air Inlet And Exhaust System".

Problem 16

The Valve Rotocoil Or Spring Lock Is Free.

Probable Cause

1. Broken Locks

   Broken locks can cause the valve to get into the cylinder. This will cause damage to the engine.

2. Broken Valve Springs

   Install new valve springs.

3. Broken Valve

   Replace the valve and replace other damaged parts.

Problem 17

Oil Is At The Exhaust.

Probable Cause

1. Too Much Oil In The Valve Compartment

   Be sure that the plugs are installed in the ends of the rocker arm shaft.

2. Worn Valve Guides

   Reconditioning of the cylinder head is required.

3. Worn Piston Rings

   Inspect piston rings and install new parts, as required.

Problem 18

Little Valve Clearance Or No Valve Clearance Is Present.

Probable Cause

1. Worn Valve Seat Or Worn Valve Face

   Reconditioning of the cylinder head is required. Make adjustment to valve lash. Refer to Testing And Adjusting, "Air Inlet And Exhaust System".

Problem 19

The Engine Has Early Wear.

Probable Cause

1. Dirt In Lubrication Oil

   Remove dirty lubrication oil. Install new filter elements. Put clean oil in the engine.

2. Air Inlet Leaks

   Inspect all gaskets and connections. Make repairs if leaks are found.

3. Fuel Leakage Into Lubrication Oil

   This will cause high fuel consumption and low engine oil pressure. This condition may also increase the oil level in the crankcase. Make repairs if leaks are found. Install new parts, as required.

Problem 20

Coolant Is In The Lubrication Oil.

Probable Cause

1. Failure Of The Engine Oil Cooler

   Install a new engine oil cooler. Drain the crankcase and refill the crankcase with clean lubricant. Install new oil filter elements.

2. Failure Of Cylinder Head Gaskets Or Failure Of Water Seals

   Check the cylinder liner projection. Install a new spacer plate gasket. Install new water seals in the spacer plate. Install a new cylinder head gasket. Tighten the bolts that hold the cylinder head. Refer to Specifications for torque values.

3. Crack Or Defect In Cylinder Head

   Install a new cylinder head.

4. Crack Or Defect In Cylinder Block

   Install a new cylinder block.

5. Failure Of Cylinder Liner Seals

   Replace cylinder liner seals.

Problem 21

Too Much Black Smoke Or Gray Smoke Is Present.

Probable Cause

1. Not Enough Air For Combustion

   Check the air cleaner for restrictions. Check the inlet manifold pressure. Inspect the turbocharger for correct operation.

2. Faulty Fuel Injection Valves

   Install new fuel injection valves.

3. Wrong Fuel Injection Timing

   Make adjustment to timing. Refer to Testing And Adjusting, "Fuel System".

Problem 22

Too Much White Smoke Or Blue Smoke Is Present.

Probable Cause

1. Too Much Lubrication Oil In Engine

   Remove extra oil. Find the source of the extra oil. Put the correct amount of oil in engine.

2. The Engine Is Misfiring Or The Engine Is Running Rough.

   Refer to "Problem 3".

3. Wrong Fuel Injection Timing

   Make adjustment to timing. Refer to Testing And Adjusting, "Fuel System".

4. Worn Valve Guides

   Reconditioning of cylinder head is required.

5. Worn Piston Rings Or Improperly Installed Piston Rings

   Inspect piston rings and install new parts, as required.

6. Failure Of Turbocharger Oil Seal

   Check the air inlet manifold for oil and repair the turbocharger, as required.

7. Coolant In Combustion System

   Check for a cracked cylinder head.

Problem 23

The Engine Has Low Oil Pressure.

Probable Cause

1. Dirty Oil Filter Or Dirty Oil Cooler

   Check the operation of the bypass valve for the filter. Clean the oil cooler or install a new oil cooler core. Remove dirty oil from the engine. Put clean oil in the engine.

2. Diesel Fuel In Lubrication Oil

   Find the source of the leakage of the diesel fuel into the lubrication oil. Make repairs, as required. Remove the lubrication oil that has been contaminated with diesel fuel. Install new oil filters. Put clean oil in the engine.

3. Too Much Clearance Between Rocker Arm Shaft And Rocker Arms

   Check lubrication in valve compartments. Install new parts, as required.

4. Faulty Oil Pump Suction Pipe

   Replacement of oil pump suction pipe is required.

5. Stuck Open Oil Pressure Relief Valve

   Clean the valve and the housing. Install new parts, as required.

6. Faulty Oil Pump

   Repair the oil pump or replace the oil pump.

7. Too Much Clearance Between Crankshaft And Crankshaft Bearings

   Inspect the crankshaft bearings and make replacement, as required.

8. Too Much Clearance Between Camshaft And Camshaft Bearings

   Inspect the camshaft and the camshaft bearings. Replace the camshaft and the camshaft bearings, as required.

9. Faulty Oil Pressure Gauge

   Install new gauge.

10. Too Much Bearing Clearance For Idler Gear

    Inspect the bearings. Replace parts, as required.

Problem 24

The Engine Uses Too Much Lubrication Oil.

Probable Cause

1. Too Much Lubrication Oil In Engine

   Remove the extra oil. Find the source of the extra oil. Put the correct amount of oil in the engine.

2. Oil Leaks

   Find all oil leaks. Make repairs, as required. Check for dirty crankcase breathers.

3. High Oil Temperature

   Check operation of oil cooler and oil temperature regulator. Install new parts, as required. Clean the oil cooler cores.

4. Too Much Oil In The Valve Compartment

   Be sure that the plugs are installed in the rocker shafts.

5. Worn Valve Guides

   Reconditioning of the cylinder head is required.

6. Worn Piston Rings And Worn Cylinder Liners

   Inspect piston rings and install new parts, as required. Reconditioning of the cylinder block can be required.

7. Failure Of Turbocharger Oil Seal

   Check the air inlet manifold for oil and repair the turbocharger, as required.

Problem 25

The Engine Coolant Is Too Hot.

Probable Cause

1. Restriction Of Coolant Flow Through Radiator Core Tubes Or Through Heat Exchanger Lines

   Clean the radiator or the heat exchanger and flush the radiator or the heat exchanger.

2. Restriction Of Air Flow Through The Radiator

   Remove all restrictions to air flow.

3. Low Fan Speed

   Check for loose fan drive belts. Adjust the fan drive belt to the correct tension. Replace belts, as required.

4. Low Coolant Level

   Add coolant to the cooling system. Check for leaks.

5. Faulty Pressure Cap

   Check operation of the pressure cap. Install a new pressure cap, as required.

6. Combustion Gases In Coolant

   Find the source of the leakage of combustion gases into the cooling system. Make repairs, as required.

7. Faulty Water Temperature Regulators

   Check water temperature regulators for correct operation. Check the water temperature gauge for correct operation. Install new parts, as required.

8. Faulty Water Pump

   Make repairs, as required. Install a new water pump, as required.

9. Too Much Load On The System

   Reduce the load on the system.

10. Wrong Fuel Injection Timing

    Make adjustment to timing. Refer to Testing And Adjusting, "Fuel System".

Problem 26

The Exhaust Temperature Is Too High.

Probable Cause

1. Leakage At Air Inlet System

   Check pressure in the air inlet manifold. Look for restrictions at the air cleaner. Correct any leaks.

2. Leakage At Exhaust System

   Find the cause of the exhaust leak. Make repairs, as required.

3. Restriction At The Air Inlet System Or The Exhaust System

   Remove the restriction.

4. Wrong Fuel Injection Timing

   Make adjustment to timing. Refer to Testing And Adjusting, "Fuel System".

Problem 27

The Starting Motor Does Not Turn.

Probable Cause

1. Low Output Of The Battery

   Check the condition of the battery. Charge the battery or replace the battery, as required.

2. Faulty Wires Or Faulty Switch

   Replace the wires or replace the switch, as needed.

3. Faulty Starter Motor Solenoid

   Install a new solenoid.

4. Faulty Starter Motor

   Repair the starter motor or replace the starter motor, as needed.

Problem 28

The Alternator Gives No Charge.

Probable Cause

1. Loose Drive Belt

   Adjust the drive belt to the correct tension.

2. Faulty Charging Circuit, Faulty Ground Return Circuit Or Faulty Battery Connections

   Inspect all cables and inspect all connections. Clean connections. Tighten connections. Replace parts, as needed.

3. Faulty Rotor (Field Coil)

   Install a new rotor.

4. Faulty Brushes (If Equipped)

   Install new brushes.

Problem 29

The Alternator Charge Rate is Low Or The Alternator Charge Rate Is Not Regular.

Probable Cause

1. Loose Drive Belt

   Adjust the drive belt to the correct tension.

2. Faulty Charging Circuit, Faulty Ground Return Circuit Or Faulty Battery Connections

   Inspect all cables and inspect all connections. Clean connections. Tighten connections. Replace parts, as needed.

3. Faulty Alternator Regulator

   Install a new alternator regulator.

4. Incorrect Alternator Regulator Adjustment

   Some alternator regulators can be adjusted and some alternator regulators can not be adjusted. Refer to Testing And Adjusting, "Electrical System".

5. Faulty Rectifier Diodes

   Replace the faulty rectifier diode.

6. Faulty Rotor (Field Coil)

   Install a new rotor.

   Note: Install a new rotor for brush type alternators only.

Problem 30

The Alternator Charge Rate Is Too High.

Probable Cause

1. Loose Connections On The Alternator Or Loose Connections On The Alternator Regulator

   Tighten all connections.

2. Faulty Alternator Regulator

   Install a new alternator regulator.

3. Incorrect Alternator Regulator Adjustment

   Some alternator regulators can be adjusted and some alternator regulators can not be adjusted. Refer to Testing And Adjusting, "Electrical System".

Problem 31

The Alternator Has Noise.

Probable Cause

1. Faulty Drive Belt

   Install a new drive belt for the alternator.

2. Loose Alternator Drive Pulley

   Check the groove in the pulley that holds the pulley in place. If the groove is worn, install a new pulley. Tighten the pulley nut. Refer to Specifications for the correct torque value.

3. The Alternator Drive Belt Is Not In Alignment With The Drive Pulley.

   Align the drive belt with the drive pulley.

4. Worn Alternator Bearings

   Install new bearings in the alternator.

5. Bent Rotor Shaft

   Install a new rotor shaft.

6. Shorted Out Rectifiers

   Install a new diode assembly.

Problem 32

The Rack Solenoid Does Not Stop The Engine.

Probable Cause

1. Incorrect Electrical Connections

   Correct the electrical connections and correct the wiring.

2. Not Enough Plunger Travel

   Make an adjustment to the plunger shaft. Replace the solenoid, as needed.

3. Wrong Shaft In The Plunger

   Install the correct shaft in the plunger.

4. Faulty Solenoid Wiring

   Install a new solenoid.