engines problems &main causes

7/31/2019 Engines Problems &Main Causes

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1a. Engine Crankshaft Will Not Turn

When Start Switch Is On

Cause

Battery Has Low Output

Wiring or Switches Have Defect Starting Motor Solenoid Has a

Defect

Starting Motor Has A Defect

Oil Pressure Switch For

Prelubrication Pump Has A Defect Prelubrication Oil Pump Has a

Defect

Correction

Make Reference to Item 25.

Make Reference to Item 25. Make Reference to Item 25.


Make a replacement of defective

switch

Repair or replace pump componentsas needed.



3

1b. Engine Crankshaft Will Not Turn

When Start Switch Is On

Cause

Inside Problem Prevents Engine

Crankshaft From Turning

Correction

If the crankshaft can not be turned

after disconnecting the drivenequipment, remove the fuel nozzles

and check for fluid in the cylinders

while turning the crankshaft. If fluid

in the cylinders is not the problem,

the engine must be disassembled to

check for other inside problems.Some of these inside problems are

bearing seizure, piston seizure,

wrong pistons installed in the

engine.



4

2a. Engine will not start

Cause

Slow Cranking Speed

Dirty Fuel Filter Dirty or Broken Fuel Lines

Fuel Pressure is Low

Correction


Install new fuel filter Clean or install new fuel lines as

necessary

At starting rpm, the minimum fuel pressure from fuel transfer pump must be 3 psi (20 kPa). If fuel pressure isless than 3 psi (20 kPa), change the

fuel filter element. Look for air in thefuel system. If fuel pressure is still low,check the fuel control valve and thefuel transfer pump for correctoperation.



5

2b. Engine will not start

Cause

No Fuel to Cylinders

Bad Quality Fuel

Wrong Fuel Injection Timing

Correction

Put fuel in fuel tank. “Prime” (removethe air and/or low quality fuel from the

fuel system)

Remove the fuel from the fuel tank.

Install a new fuel filter element. Put a

good grade of clean fuel in the fuel

tank.

Make adjustment to timing.



6

3a. Misfiring Or Running Rough

Cause


Correction

Make sure there is fuel in the fuel tank.Look for leaks or bad bends in the fuel

line between fuel tank and fuel transfer pump. Look for air in the fuel system,sticking, binding or defective fuelcontrol valve. Check fuel pressure. Theoutlet pressure of the fuel transfer pump must be a minimum of 20 psi(140 kPa) at full load speed.

If fuel pressure is lower than the above pressure, install a new filter element. If fuel filter is still low, check the fueltransfer pump.



7

3b. Misfiring Or Running Rough

Cause

Air In Fuel System

Leak or Break in Fuel Line Between

Injection Pump and Injection Valve

Wrong Valve Clearance

Correction

Find the air leak in the fuel system andcorrect it. If air is in the fuel system it

will generally get in on the suction side

of the fuel transfer pump.

Install a new fuel line.

Make adjustment according to Testing

and Adjusting.



8

3c. Misfiring Or Running Rough

Cause

Defect in Fuel Injection valve(s) or Injection Pump(s).


Correction

Run engine at rpm that gives maximummisfiring or rough running. Then

loosen a fuel line nut on the injection

valve for each cylinder, one at a time.

Find the cylinder where loosening the

fuel line nut does not change the way

the engine runs. Test the injection

pump and injection valve for thatcylinder. Install new parts where

needed.




9

4a. Stall At Low RPM

Cause


Correction

Make sure there is fuel in the fuel tank.Look for leaks or bad bends in the fuel

line between fuel tank and fuel transfer pump. Look for air in the fuel system,sticking, binding or defective fuelcontrol valve. Check fuel pressure. Theoutlet pressure of the fuel transfer pump must be a minimum of 20 psi(140 kPa) at full load speed.

If fuel pressure is lower than the above pressure, install a new fuel filter element. If fuel pressure is still low,check the fuel transfer pump.



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4b. Stall At Low RPM

Cause

Idle rpm Too Low

Correction

Make adjustment to governor so idle

rpm is the same as given in the RACK

SETTING INFORMATION.



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4c. Stall At Low RPM

Cause

Defect in Fuel Injection Valve(s) or

Fuel Injection Pump(s)

Engine Accessories.

Correction


loosen a fuel line nut on the injection pump for each cylinder, one at a time.Find the cylinder where loosening thefuel line nut does not change the waythe engine runs. Test the injection pump and injection valve for thatcylinder. Install new parts where

needed.

Check engine accessories for damageand correct adjustment. If necessary,disconnect the accessories and test theengine.



12

5. Sudden Changes In Engine Speed (rpm)

Cause

Failure of Governor or Fuel Injection

Pump

Correction

Look for damaged or broken springs,

linkage or other parts. Remove the

governor. Check for free travel of the

fuel rack. Be sure fuel injection pumps

are installed correctly. Check for

correct governor spring. Install new

parts for those that have damage or

defects.



13

6a. Not Enough Power Cause

Bad Quality Fuel


Correction

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

Make sure there is fuel in the fuel tank.Look for leaks or bad bends in the fuelline between fuel tank and fuel transfer pump. Look for air in the fuel system,sticking, binding or defective fuelcontrol valve. Check fuel pressure. The

outlet pressure of the fuel transfer pump must be a minimum of 20 psi(140 kPa) at full load speed.

If the fuel pressure is lower than theabove pressure, install a new fuel filter element. If fuel pressure is still low,check the fuel transfer pump.



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6b. Not Enough Power

Cause

Leaks in Air Inlet System

Governor Linkage

Wrong Valve Clearance

Correction

Check the pressure in the air intake

manifold. Look for restrictions in the air

cleaner.

Make adjustment to get full travel of linkage.

Install new parts of those that have damage

or defects.

Make adjustment according toSpecifications.



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6c. Not Enough Power

Cause

Defect in Fuel Injection Valve(s) or

Fuel Injection Pump(s)


Correction


loosen a fuel line nut on the injection pump for each cylinder, one at a time.Find the cylinder where loosening thefuel line nut does not change the waythe engine runs. Test the injection pump and injection valve for thatcylinder. Install new parts where

needed.




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6d. Not Enough Power

Cause

Rack Setting Too Low

Fuel Ratio Control Has Wrong

Adjustment or Defect

Turbocharger has Carbon Deposit

Correction

Make reference to the RACK SETTING

INFORMATION. Make adjustment to control. Check for

bad diaphragm and weak or broken

springs. Replace parts if needed.

Inspect and repair turbocharger as

necessary.



17

7. Too Much Vibration

Cause

Vibration damper or Pulley is Loose

Vibration Damper Has A Defect

Engine Supports Are Loose, Worn or Have a Defect

Driven Equipment is not in Alignmentor is Out of Balance

Flexible Coupling Between Engine andDriven equipment Has a Defect

Misfiring or Running Rough

Correction

Check vibration damper and pulley for

damage. Tighten bolts or nuts. If

vibration damper or pulley bolt holes

have damage or wear, replace with new

parts.

Install a new vibration damper

Tighten all mounting bolts. Install new

components if necessary.

Check alignment and balance, correct

if needed.

Repair or replace coupling

components.

Make reference to item 3.



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8. Loud Combustion Noise (Sound)

Cause

Bad Quality Fuel

Defect in Fuel Injection Valve(s) or Fuel Injection Pump(s)


Correction

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

Run engine at rpm that givesmaximum misfiring or rough running.Then loosen a fuel line nut on theinjection pump for each cylinder, oneat a time. Find the cylinder whereloosening the fuel line nut does notchange the way the engine runs. Testthe injection pump and injection valvefor that cylinder. Install new partswhere needed.




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9. Valve Train Noise (Clicking)Cause

Broken Valve Spring(s) or Locks

Not Enough Lubrication

Too Much Valve Clearance

Correction

Install new parts where necessary.Broken locks can cause the valve toslide into the cylinder. This will causemuch damage.

Check lubrication in valvecompartment. There must be a strongflow of oil at engine high rpm, but onlya small flow of oil at low rpm. Oil passages must be clean, especiallythose sending oil to the cylinder head.

Make adjustment according to Testingand Adjusting.



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10. Oil In Cooling SystemCause

Defect In Core of Oil Cooler

Failure of Cylinder Head Gasket

Correction

Install a new core in the oil cooler

Check cylinder liner projection.

Replace head gasket.



21

11. Mechanical Noise (Knock) In Engine

Cause

Failure of Bearing For Connecting Rod

Damaged Timing Gears

Defect in Attachment.

Correction

Inspect the bearing for the

connecting rod and the bearing

surface (journal) on the crankshaft.

Install new parts where necessary.

Install new parts where necessary.

Repair or install new components.



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12. Fuel Consumption Too High

Cause

Fuel System Leaks

Fuel and Combustion Noise (Knock)


Correction

Replacement of parts is needed at

points of leakage.

Make Reference to Item 3 and Item 6.




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13. Loud Valve Train Noise

Cause

Broken Valve Spring(s)

Broken Camshaft

Correction

Make replacement of parts with damage

Make replacement of parts with damage.

Clean engine thoroughly.



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14a. Too Much Valve Lash

Cause

Not Enough Lubrication

Rocker Arm Worn at Face That

Contacts End of Valve

Correction

Check lubrication in valve

compartment. There must be a strong

flow of oil at engine high rpm, but only

a small flow at low rpm. Oil passages

must be clean, especially those sendingoil to the cylinder head.

If there is too much wear, install new

parts or rocker arms. Make adjustment

of valve clearance according to Testing

and Adjusting.



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14b. Too Much Valve Lash

Cause

End of Valve Stem Worn

Worn Push Rods

Correction


valves. Make adjustment to valve

clearance according to Testing and

Adjusting.


push rods. Make adjustment of valve


Adjusting.



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14c. Too Much Valve Lash

Cause

Valve Lifters Worn

Broken or Worn Valve Lifters

Correction


valve lifters. Make adjustment of valve


Adjusting.

Install new valve lifters. Check

camshaft for wear. Check for free

movement of valves or bent valve

stem. Clean engine thoroughly. Make

adjustment of valve clearance

according to Testing and Adjusting.



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14d. Too Much Valve Lash

Cause

Worn Cams on Camshaft

Correction

Check valve clearance. Check for free

movement of valves or bent valve

stems. Install a new camshaft. Make

adjustment of valve clearanceaccording to Testing and Adjusting.



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15. Valve Rotocoil Or Spring Lock Is Free

Cause

Broken Locks

Broken Valve Spring(s)

Broken Valve

Correction

Broken locks can cause the valve to

slide into the cylinder. This will cause

much damage.

Install new valve spring(s).

Replace valve and other damaged

parts.



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16. Oil At The Exhaust

Cause

Too Much Oil in the Valve

Compartment

Worn Valve Guides

Worn Piston Rings

Correction

Look at both ends of the rocker arm

shaft. Be sure that there is a plug in

each end.

Reconditioning of the cylinder head isneeded.

Inspect and install new parts as needed.



30

17. Little Or No Valve Clearance

Cause

Worn Valve Seat or Face of Valve

Correction

Reconditioning of cylinder head is

needed. Make adjustment of valve

clearance according to Testing andAdjusting.

.



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18. Engine Has Early Wear

Cause

Dirt in Lubricating Oil

Air Inlet Leaks

Fuel Leakage Into Lubrication Oil

Correction

Remove dirty lubrication oil. Install anew oil filter element. Put clean oil inthe engine. Check oil filter bypassvalve for a weak or broken spring.

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

This will cause high fuel consumptionand low engine oil pressure. Makerepairs if leaks are found. Install new

parts where needed.

.



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19. Coolant In Lubrication Oil

Cause

Failure of Oil Cooler Core

Failure of Cylinder Head Gasket

Crack or Defect in Cylinder Head

Crack or Defect in Cylinder Block

Failure of Liner Seals

Correction

Install a new core for the oil cooler.Drain crankcase and refill with cleanlubricant. Install new oil filter element.

Check cylinder liner projection. Install anew cylinder head gasket. Tighten the bolts holding the cylinder head,according to the specifications.

Install a new cylinder head.

Install a new cylinder block.

Replace seals.

.



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20. Too Much Black Or Gray Smoke

Cause

Not Enough Air For Combustion

Bad Fuel Injection Valve(s)


Defect in Fuel Ratio Control

Correction

Check air cleaner for restrictions.

Test fuel injection valves. Replace bad

valves.


Make an adjustment to control. Check for broken springs. Replace if needed.

.



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21a. Too Much White or Blue Smoke

Cause

Too Much Lubrication Oil in

Engine

Misfiring or Running Rough


Correction

Remove extra oil. Find where extra oil

comes from. Put correct amount of oil

in engine. Do not put too much oil in

engine.

Make reference to item 3.


.



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21b. Too Much White or Blue Smoke

Cause

Worn Valve Guides

Worn Piston Rings

Failure of Turbocharger Oil Seal

Correction

Reconditioning of cylinder head isneeded.

Install new piston rings.

Check inlet manifold for oil andrepair turbocharger if necessary.

.



36

22a. Engine Has Low Oil Pressure

Cause

Dirty Oil Filter or Oil Cooler

Diesel Fuel in Lubrication Oil

Correction

Check the operation of bypassvalve for the filter. Install new oilfilter elements if needed. Clean or

install new oil cooler core.Remove dirty oil from engine. Putclean oil in engine.

Find the place where diesel fuelgets into the lubrication oil. Make

repairs as needed. Remove thelubrication oil that has diesel fuelin it. Install a new oil filter element. Put clean oil in theengine.



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22b. Engine Has Low Oil Pressure

Cause

Too much Clearance between Rocker

Arm Shaft and Rocker Arms

Oil Pump Suction Pipe Has A Defect

Pressure Regulating Valve Does Not

Close

Correction

Check lubrication in valve

compartment. Install new parts as

necessary.

Replacement of pipe is needed.

Clean valve and housing. Install new

parts as necessary.



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22c. Engine Has Low Oil Pressure

Cause

Oil Pump Has A Defect

Too Much Clearance Between

Crankshaft and Crankshaft Bearings

Too much Clearance between

Camshaft and Camshaft Bearings.

Defect in Oil Pressure Gauge

Correction

Repair or replace oil pump.

Check the oil filter for correct

operation. Install new parts if

necessary.

Install new camshaft and camshaft

bearings if necessary.

Install new gauge.



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23a. Engine Uses Too Much Lubrication Oil

Cause

Too Much Lubricating Oil In Engine

Oil Leaks

Oil Temperature is Too High

Correction

Remove extra oil. Find where extra oil

comes from. Put correct amount of oil

in engine. Do not put too much oil in

engine.

Find all oil leaks. Make repairs as

needed. Check for dirty oil breather.

Check operation of oil cooler. Install

new parts if necessary. Clean the core

of the oil cooler.



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23b. Engine Uses Too Much Lubrication Oil

Cause

Too Much Oil in the Valve

Compartment.

Worn Valve Guides

Worn Piston Rings

Correction

Look at both ends of the rocker arm

shaft. Be sure that there is a plug in

each end.

Reconditioning of the cylinder head is

needed.

Inspect and install new parts as needed.



41

24a. Engine Coolant Is Too Hot

Cause

Restriction To Flow of CoolantThrough Radiator Core Tubes

Restriction To Air Flow ThroughRadiator

Low Fan Speed

Not Enough Coolant in System

Pressure Relief Valve Has a Defect

Correction

Clean and flush radiator.

Remove all restrictions of flow.

Check for work or loose fan belts.

Add coolant to cooling system. Check for leaks.

Check operation of pressure relief valve. Install a new pressure relief valve if necessary.



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24b. Engine Coolant Is Too Hot

Cause

Combustion Gases in Coolant

Water Temperature Regulators

(Thermostats) or Temperature GaugeHas a Defect

Water Pump Has A Defect

Too Much Load On The System


Correction

Find out where gases get into thecooling system. Make repairs asneeded.

Check water temperature regulators for correct operation. Check temperaturegauge operation. Install new parts asnecessary.

Make repairs to the water pump asnecessary.

Make a reduction to the load.




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25. Starting Motor Does Not Turn

Cause

Battery Has Low Output

Wiring or Switch Has Defect

Starting Motor Solenoid Has A Defect

Starting Motor Has A Defect

Correction

Check condition of battery. Charge battery

or make replacement as necessary.

Make repairs or replacement as necessary.

Install a new solenoid.

Make repair or replacement of startingmotor.



44

26. Alternator Gives No Charge

Cause

Loose Drive Belt For Alternator

Charging or Ground Return Circuit or

Battery Connections Have A Defect

Brushes Have A Defect

Rotor (Field) Has A Defect

Correction

Make an adjustment to put the correcttension on the drive belt.

Inspect all cables and connections.Clean and tighten all connections.Make replacement of parts with defect.

Install new brushes.

Install a new rotor.



45

27a. Alternator Charge Rate Is Low Or Not Regular

Cause

Loose Drive Belt For Alternator

Charging or Ground Return Circuit or

Battery Connections Have A Defect

Alternator Regulator Has A Defect

Correction

Make an adjustment to put thecorrect tension on the drive belt.

Inspect all cables and connections.Clean and tighten all connections.Make replacement of parts withdefect.

Make an adjustment or replacement of alternator regulator.



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27b. Alternator Charge Rate Is Low |Or Not Regular

Cause

Alternator Brushes Have A Defect

Rectified Diodes Have A Defect

Rotor (Field Coil) Has A Defect

Correction

Install new brushes.

Make replacement of rectifier diode that has a defect.

Install a new rotor.



47

28. Alternator Charge Too High

Cause

Alternator or Alternator Regulator Has

Loose Connections.

Alternator Regulator Has A Defect

Correction

Tighten all connections to

alternator or alternator regulator.

Make adjustment or replacement

of alternator regulator.



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29. Alternator Has Noise

Cause

Drive Belt For Alternator is Worn Or

Has A Defect.

Loose Alternator Drive Pulley

Drive Belt and Drive Pulley For

Alternator Are Not in Alignment.

Worn Alternator Bearings

Correction

Install a new drive belt for thealternator.

Check groove in pulley for key thatholds pulley in place If groove is worn,install a new pulley. Tighten pulley nutaccording to Specifications.

Make an adjustment to put drive beltand drive pulley in correct alignment.

Install new bearings in the alternator.



30. Exhaust Temperature Is Too High

Cause

Air Inlet System Has A Leak

Exhaust System Has A Leak

Air Inlet or Exhaust System Has A

Restriction


Correction

Check pressure in the air intake

manifold. Look for restrictions at

the air cleaner. Correct any leaks.

Find cause of exhaust leak. Make

repairs as necessary.

Remove restriction

Make an adjustment to the timing.

engines problems &main causes

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