easyfindcarparts.com Home Page Home / Manufacturers List   Engine Troubleshooter Engine Troubleshooter   easyfindcarparts Contact Contact                                    EasyFindCarParts on Facebook

EasyFind Car Parts

New & Used Parts for Classic Cars

 

Engine Troubleshooter

If the engine in your old classic car is giving you problems this page comprehensively lists possible causes for a variety of symptoms. It covers all common components in the fuel, ignition & electrical systems plus the internal mechanical parts such as pistons, valves, connecting rods, crankshaft & bearings etc.

Select Symptom:

Engine not starting or hard to start

Engine misfiring at idle or slow speed

Engine misfiring at high speed

Loss of engine compression

Engine backfires through the carburetor

Pre ignition or spark knock

Excessive oil consumption

Low oil pressure

High oil pressure

Crankshaft noise

Connecting rod noise

Piston noise

Valve noise

Engine vibration at idle

Engine vibration at high speed

Oil pump & distributor shaft noise

Excessive fuel consumption

Starter not functioning correctly

Generator / dynamo not charging

High engine temperature

 

Engine not starting or hard to start:

Ignition Wiring Connections:

1.Loose or corroded connections at the ammeter, ignition switch, coil or distributor.
2.Low tension wire insulation cracked or worn through.
3.Poor low-tension wire ground connection.
4.Loose, corroded or burned ignition switch contacts.
5.Faulty ammeter.
6.Loose or corroded high tension terminals or cable sockets.
7.Cracked, oil soaked, wet chafed or worn high-tension cable insulation.
8.High tension cables installed not according to engine Firing order.
9.High tension cable from coil to distributor not connected.
10.Poor ground between coil and its mounting.
11.Poor ground between distributor and engine.

Distributor:

1.Breaker point gap much too wide.
2.Breaker points not synchronized properly.
3.Breaker points dirty, cracked, pitted or burned.
4.Breaker arm spring weak or broken.
5.Breaker arm sticking.
6.Breaker arm grounded due to worn or broken insulating bushing.
7.Breaker arm rubbing block loose or badly worn.
8.Breaker arm plate loose or not properly grounded.
9.Loose breaker plate terminal posts.
10.Breaker pigtail Lead wires loose or broken.
11.Breaker cam loose due to burrs on cam locking screw taper.
12.Incorrect ignition timing.
13.Distributor cap cracked.
14.Distributor cap inserts bent, loose or badly burned.
15.Too much clearance between distributor cap inserts and rotor.
16.Grounded rotor.
17.Broken, loose or bent rotor spring.
18.Distributor cap center terminal (rotor contact missing or broken.
19.Distributor cap wet or dirty.
20.Broken or bent distributor shaft.
21.Distributor shaft worn.
22.Distributor shaft bushing or bearing loose or worn.
23.Distributor drive gear or coupling sheared, broken or loose on shaft.
24.Distributor drive gear not properly with oil pump drive gear.
25.Automatic spark advance installed backwards.
26.Weak or grounded condenser.
27.Defective coil.
28.Cracked coil tower.
29.Wet or dirty coil tower.

Battery:

1.Battery in low state of charge.
2.Battery completely discharged.
3.Poor ground connection between battery and frame.
4.Poor ground connection between frame and engine.
5.Battery terminals badly corroded or loose.
6.Cable from starter to battery broken, or terminal cracked.
7.Cable from starter to battery is 12 volt and not 6 volt (0 or 00 gauge).
8.Cable loose in terminal socket.
9.Dead cell in battery.
10.Under-sized battery cables.

Spark Plugs:

1.Plugs operating too cold, causing fouling.
2.Fouled plugs due to an excessively rich carburetor mixture.
3.Fouled plugs due to engine oil passing piston rings.
4.Fouled plugs due lo their being loose in cylinder head.
5.Fouled plugs due to damaged or ineffective plug gaskets.
6.Fouled plugs due to improper operation of choke.
7.Use of too hot operating plugs, causing pre-ignition.
8.Spark plug gaps much too wide.
9.Use of some types of spark plug and coil radio suppressors.
10.Spark plugs damp or covered with dirt.

Starter Motor:

1.Broken starter pinion.
2.Broken flywheel ring gear.
3.Sticking starter due to burred tooth on starter pinion or flywheel gear.
4.Broken Bendix spring.
5.Oil congealed in starter drive due to the use of too heavy a grade.
6.Starting switch not operating properly.
7.Starting switch not grounded properly. Switch contacts burned or corroded.
8.Rotation of starter prevented due to teen armature shaft, cracked or distorted housing, tight bearings, misaligned bearings, lack of lubrication, sludge formation in starter drive, starter not aligned properly with engine.
9.Rotation of starter prevented due to timed loose brush connections, loose pigtails, brushes sticking in holders, bent brush plate holder arms, weak or broken brush springs, sticking brush holders, incorrect type of brushes, brushes worn too short.
10.Armature shorted.
11.Commutator surface dirty, burned, pitted or excessively lubricated.
12.High mica between commutator segments due to worn commutator.
13.Brush ring set incorrectly or grounded.
14.Excessive brush spring tension, causing rapid wear of brushes and commutator.
15.Burned out, shorted or open circuited field coils.
16.Brushes sticking in brush holder.
17.Worn bushings or bearings causing armature to drag against pole pieces.

Fuel System:

1.Intake manifold and cylinders hooded with fuel due to faulty choke operation.
2.Old, stale or a poor grade of fuel being used, particularly during cold weather or after being in dead storage.
3.Air Leaks due to cracked intake manifold, air horn gasket broken or damaged, worn throttle she fit bearing, loose manifold attaching nuts, loose carburetor attaching nuts, warped carburetor flange, broken or damaged intake manifold or carburetor gaskets, poor vacuum line connection at the intake manifold, loose or missing intake manifold core hole plugs or warped choke cover.
4.Choke valve fails to close fully when starting a cold engine. Broken or loose choke wire.
5.Low carburetor float or fuel level.
6.Clogged or dirty carburetor screen.
7.Inoperative fuel pump.
8.Restricted, broken or clogged fuel line from the pump to carburetor.
9.Restrictions in carburetor passages due to presence of ice, corrosion or water.
10.No fuel supply.
11.Ice formation in fuel pump sediment trap.
12.Vapor lock.
13.Automatic choke control faulty or sticking.
14.Leaky carburetor jet gasket so that carburetor is dry after car is parked for some time.

Loss of Engine Compression:

1.Spark plugs loose in cylinder head.
2.Cylinder head bolts loose.
3.Piston rings which are broken, badly worn, weak or stuck.
4.Cylinder head gasket damaged or improperly installed.
5.Valves held open due to insufficient tappet clearance.
6.Valves held open due to warped corroded or gummed stems.
7.Valve seating poorly.
8.Valve springs weak or broken.

Other Conditions:

1.Broken or loose camshaft or distributor drive shaft gear.
2.Valves improperly timed.
3.Cracked cylinder block.
4.Water in cylinder.
5.Excessive internal friction of engine assembly due to insufficient clearances.
6.Broken or jammed internal parts of clutch or transmission.
7.Engine "seized" due to excessive overheating.
8.Broken flywheel ring gear.
9.Gasoline tank filler cap clogged.
10.Sludge conditions due to water in oil.

BACK TO TOP

Engine misfiring at idle or slow speed:

Ignition:

1.Loose or corroded connections or terminals at the ammeter, ignition switch, coil or distributor.
2.Slight short in primary circuit wiring.
3.Poor low tension wire ground connection.
4.Loose, corroded or burned ignition switch contacts.
5.Loose or corroded high tension terminals or cable sockets.
6.Cracked, oil soaked, wet, chafed or worn high tension cable insulation.
7.Poor ground between coil and its mounting.
8.Poor ground between distributor and engine.
9.Breaker point gap incorrect.
10.Breaker points not synchronized properly.
11.Breaker points dirty, cracked pitted or burned.
12.Breaker arm spring weak or broken.
13.Breaker arm sticking.
14.Breaker arm insulating bushing worn.
15.Breaker arm plate loose or note properly grounded.
17.Loose breaker plate terminal posts.
18.Breaker plate pigtail leads loose or broken.
19.Breaker cam with low lobe.
20.Breaker cam loose due to burrs on cam locking screw taper.
21.Incorrect ignition timing.
22.Distributor cap cracked, wet or dirty.
23.Distributor cap inserts bent, loose or badly burned.
24.Distributor shaft bent or worn.
25.Distributor shaft bushing or bearing loose or worn.
26.Weak condenser.
27.Defective coil.
28.Cracked, wet or dirty coil tower.
29.Defective spark plug or coil radio suppressor.
30.Defective spark plugs.
31.Spark plugs not gapped properly.
32.Weak battery.
33.Ruptured automatic advance diaphragm.

Fuel System:

1.Float level too high or too low.
2.Idle adjusting screws (dual carburetors) not properly balanced.
3.Throttle valves (dual carburetors) not properly synchronized.
4.Restricted or partially clogged idle air passage.
5.Restricted or partially clogged idle jet or passage.
6.Air leaking around throttle shaft.
7.Air leaking around idle tube.
8.Loose manifold connections.
9.Air leak in vacuum lines.
10.Loose manifold nuts.
11.Broken or damaged carburetor or intake manifold gaskets.
12.Cracked intake manifold.
13.Contacting surface of intake manifold warped or damaged.
14.Slight leak at check valves in fuel pump.
15.Punctured diaphragm in vacuum section of combination fuel pump causing fouled spark plugs due to oil being drawn into cylinders.

Other Conditions:

1.Unequal compression in cylinders.
2.Slight water leak in cylinders or combustion chambers.

BACK TO TOP

Engine misfiring at high speed:

Ignition:

1.Loose or corroded connections or terminals at the ammeter, ignition switch, coil or distributor.
2.Slight short in primary circuit wiring.
3.Poor low tension ground connection.
4.Loose, corroded or burned ignition switch contacts.
5.Loose or corroded high tension terminals or cable sockets.
6.Cracked, oil soaked, wet, chafed or worn high tension cable insulation.
7.Broken wire inside of cable.
8.Stray cable strand shorting spark plug.
9.Poor ground between distributor and engine.
10.Breaker point gap incorrect.
11.Breaker points not synchronized properly.
12.Breaker points dirty, cracked, pitted or burned.
13.Breaker arm spring weak.
14.Breaker arm insulating bushing worn.
15.Breaker arm rubbing block loose or badly worn.
16.Breaker arm plate loose or not properly grounded.
17.Loose breaker plate terminal posts.
18.Breaker plate pigtail leads loose or broken 19.Breaker cam with low lobe.
20.Breaker cam loose due to burrs on cam locking screw taper.
21.Incorrect ignition timing.
22.Distributor cap cracked, wet or dirty.
23.Distributor cap inserts bent, loose or badly burned.
24.Bent or worn distributor shaft.
25.Distributor shaft bushing or bearing loose or worn.
26.Automatic spark advance plate loose.
27.Automatic advance governor springs weak or broken.
28.Automatic advance governor weight pins worn.
29.Weak condenser.
30.Defective coil.
31.Cracked, wet or dirty coil tower.
32.Defective spark plugs.
33.Spark plug gapped too wide.
34.Spark plugs operating too hot or too cold.
35.Spark plugs loose in cylinder head.
36.Fouled plugs due to damaged or ineffective gaskets.
37.Faulty radio suppressor.
38.Pre-ignition due to any source.
39.Weak battery in combination with an inoperative generator.

Fuel System:

1.Dirty air cleaner.
2.Restricted air passages in air cleaner silencer.
3.Oil level too high in oil bath type air cleaner, causing restriction.
4.Choke valve not fully open.
5.Punctured diaphragm in vacuum section of combination fuel pump, causing fouled spark plugs due to oil being drawn into cylinder.
6.Float level too low.
7.Throttle valves (dual carburetors) 8.Air leak around throttle shaft.
9.Loose manifold connections.
10.Air leak in vacuum lines.
11.Loose manifold nuts.
12.Broken or damaged carburetor or intake manifold gaskets.
13.Cracked intake manifold.
14.Contacting surface of intake manifold being warped or damaged.
l5.Slight leak at check valves in fuel pump.
16.Improper setting of economizer valve in carburetor.
17.Carburetor throttle lever loose on shaft.
18.Water in gasoline.
19.Clogged filter screens.

Valves:

1.Warped valve face.
2.Valve leaks due to faulty seating.
3.Valve sticking 4.Valve Badly burned.
5.Cracked valve seat.
6.Valve spring weak or broken.
7.Bent valve stem.
8.Valve stem too tight in its guide.
9.No or too great tappet clearance.
10.Sticking rocker arm.
11.Broken mushroom on valve lifter.
12.Valve held open due to shoulder on valve face.
13.Valve held open due to carbon on valve seat.
14.Valve held open due to gum on valve stem.

Other Conditions:

1.Partially restricted or clogged muffler, exhaust pipe or tail pipe.
2.Engine overheated.
3.Unequal or lack of engine cylinder compression.
4.Manifold heat control valve held in closed position.
5.Cracked cylinder head.
6.Broken cylinder head gasket.

BACK TO TOP

Loss of engine compression:

Valves:

1.Weak or broken valve springs.
2.Valves held open due to insufficient tappet clearance.
3.Sticking valves due to insufficient valve stem-to-guide clearance.
4.Sticking valves due to carbon deposits or gum on the valve stems and in the valve guides.
5.Warped or broken valve heads.
6.Bent valve stems.
7.Pitted, burned or distorted valve seats. The entire list of defects in engine parts has already been completed. It will be evident from the two samples above that by explaining what engine troubles detects will cause, the reader mill have an excellent background for using our system of diagnosis intelligently.

Piston & Ring Conditions:

1.Scored cylinder walls.
2.Excessive clearance between cylinder walls and pistons.
3.Tapered or eccentric cylinder bores.
4.Worn ring grooves.
5.Undersized rings.
6.Hole in piston head.
7.Insufficient ring tension.
8.Rings stuck in grooves due to gum or carbon deposit.
9.Scored piston ring faces.
10.Scored pistons.
11.Insufficient piston ring end gap clearance may cause scored cylinders.

Other Conditions:

1.Broken cylinder head gasket.
2.Loose cylinder head bolts.
3.Spark plugs loose in cylinder head.
4.Compression loss due to faulty spark plug gaskets.
5.Warped cylinder head.

BACK TO TOP

Engine backfires through carburetor:

Check:

1.Incorrect valve timing.
2.Incorrect ignition timing.
3.Improper choke action in conjunction with cold engine.
4.Intake valves not seating properly.
5.Pre-ignition.
6.Excessively lean carburetor mixture.
7.Abnormally rich carburetor mixture.
8.Intake manifold air leaks.
9.Broken cylinder head gasket between cylinders.
10.Spark plug cables installed not according to engine firing order.
11.Distributor governor sticking.
12.Poor quality fuel 13.Shorted distributor cap.
14.Wet distributor cap or wires.

BACK TO TOP

Pre ignition or spark knock:

Check:

1.Ignition timed too early.
2.Weak distributor automatic advance springs.
3.Combustion chamber with large carbon deposits.
4.Spark advance not operating upon acceleration.
5.Use of spark plug which is too hot.
6.Spark plug electrodes or insulators burned or carbonized.
7.Sharp metallic edges in combustion chamber.
8.Cylinder head gasket projecting into combustion chamber.
9.Excessively lean carburetor mixture.
10.Automatic heat control valve held in closed position.
11.Engine overheated.
12.Poor grade of fuel.
13.Old or stale fuel which has lost its volatility.
14.Using a high compression cylinder head with standard fuel.
15.Hot engine valves caused by incorrect valve seat width.
16.Hot engine valves caused by insufficient tappet clearance.
17.Hot engine valves due to use of wrong type or valves having thin edges.

BACK TO TOP

Excessive oil consumption:

External Leaks:

1.Leak at oil gauge pipe connections.
2.Leak at oil filter lines.
3.Improperly installed rear camshaft bearing Welch plug.
4.Loose rear camshaft bearing Welch plug.
5.Loose fuel pump or faulty gasket.
6.Timing gear cover not properly centered.
7.Faulty crankshaft oil scats.
8.Crankshaft pulley hull eccentric.
9.Restricted oil return groove in pulley hub.
10.Rough crankshaft pulley hub.
11.Crankshaft pulley nut, washer or gasket not properly installed.
12.Oil pan gasket broken or improperly installed.
13.Oil pan cap screws loose.
14.Oil pan gasket flange distorted.
15.Oil pan cracked.
16.Oil pan drain plug loose.
17.Oil pan drain plug gasket missing or damaged.
18.Timing gear cover gasket broken or improperly installed.
19.Timing gear cover bolts loose.
20.Timing gear cover flange distorted.
21.Timing gear cover cracked.
22.Valve cover plate gasket broken or improperly installed.
23.Breather housing or housing tube loose or clogged.
24.Oil pump cover gasket broken, loose or improperly installed.
25.Valve stems or guides worn.

Internal Conditions:

1.Piston rings badly worn or scuffed.
2.Broken piston rings.
3.Insufficient ring tension.
4.Insufficient end gap clearance of piston rings which may cause cylinder scores.
5.Poor quality oil.
6.Oil of improper viscosity.
7.Oil which is badly diluted.
8.Excessive amount of oil in oil pan.
9.Continuous high speed operation.
10.Excessive oil pressure.
11.Punctured diaphragm in vacuum section of combination fuel pump.
12.Scuffed pistons.
13.Excessive clearance between cylinder walls and pistons.
14.Tapered, scored or eccentric cylinder bores.
15.Abnormally high crankcase temperatures.
16.Excessive clearance between intake valve stems and guides.
17.Crankshaft journals out of round.
18.Main and connecting rod bearings with excessive end wise or radial clearance.
19.Cylinder block distorted due to uneven tightening of cylinder head bolts.
20.Bearing chipped.

BACK TO TOP

Low oil pressure:

Check:

1. Excessive clearance between push rods and guides.
2. Use of badly diluted engine oil.
3. Use of too light a grade of engine oil.
4. Oil pump intake screen clogged with water, sludge, fee or dirt.
5. Weak or broken oil relief valve spring.
6. Relief valve spring not adjusted properly.
7. Relief valve face or seat distorted.
8. Relief valve face or seat held open by dirt, ate.
9. Air leak in oil pump suction line.
10. Excessive clearance of oil pump gears in pump body.
11. Oil pump gears which are damaged or badly worn.
12. Loose oil pump body or cover.
13. Oil pump gaskets improperly installed or damaged.
14. Broken oil pipe or tube.
15. Loose oil pipe or tube connections.
16. Excessive clearance of main, connecting rod or camshaft bearings.
17. Inaccurate oil pressure gauge giving an impression of low oil pressure.
18. Bearings chipped.
19. Bearing caps filed out of round.

BACK TO TOP

High oil pressure:

Check:

1. Use of too heavy a grade of engine oil.
2. Restricted oil passage at the relief valve.
3. Relief valve improperly adjusted.
4. Relief valve spring too stiff or too heavy.
5. Stuck relief valve.
6. Inaccurate oil pressure gauge gives impression of high oil pressure.

BACK TO TOP

Crankshaft noise:

Check:

1.Loose crankshaft gear or sprocket.
2.Loose flywheel.
3.Loose vibration damper.
4.Engine oil too thin due to dilution.
5.Sprung crankshaft.
6.Excessive radial bearing clearance.
7.Excessive crankshaft end play.
8.Low oil pressure.
9.Bearing misalignment.
10.Out of round or eccentric journals.
11.Insufficient oil supply.
12.Distorted crankcase.
13.Broken crankcase web.
14.Flywheel or clutch out of balance.

BACK TO TOP

Connecting rod noise:

Check:

1.Out of round or eccentric crank pins.
2.Excessive radial bearing clearance.
3.Insufficient oil supply.
4.Low oil pressure.
5.Engine oil too thin due to dilution.
6.Connecting rods misaligned.
7.Bearing caps filed.
8.Oil dippers not supplying oil to bearings.

BACK TO TOP

Piston noise:

Check Pistons for:

1.Collapsed piston skirts.
2.Insufficient piston pin clearance.
3.Excessive clearance between piston and cylinder bore.
4.Connecting rod misalignment.
5.Tapered or eccentric cylinder bores.
6.Rings or piston butting against ridge at of cylinder bore.
7.Piston head buying against projecting cylinder head gasket.
8.Broken or stuck piston rings.
9.Excessive vertical clearance between ring and ring groove.
10.Piston pin hole not square with the piston.
11.Piston ring lands not relieved properly.
12.Piston head butting against carbon accumulation at of cylinder bore.
13.Scored piston.
14.Piston pin frozen.

Check Piston Pins for:

1.Loose piston pin clamp screw.
2.Excessive piston pin clearance.
3.Piston slap caused by insufficient piston pin clearance.
4.Piston pin loose in connecting rod.
5.Piston pin rubbing cylinder wan.
6.Upper end of connecting rod rubbing against piston pin boss.
7.Oil passage through rod clogged.

BACK TO TOP

Valve noise:

Check:

1. Worn lifter adjusting screw face.
2. Lifter adjusting screw face not machined properly.
3. Lifter adjusting screw threads stripped or crossed.
4. Weak valve springs.
5. Excessive valve stem to tappet clearance.
6. Lifter assembly loose on the cylinder block.
7. Excessive clearance between lifter and guide.
8. Lifter misaligned on cylinder block.
9. Lower end of the lifter broken, worn, chipped, rough or scored.
10. Too much or too little clearance between valve stem and guide.
11. Warped valve head.
12. Valve head face or valve seat face not concentric with valve stem axis.
13. Rough cam surfaces.
14. Rough lifter bore surfaces.
15. Valve seat insert loose.

BACK TO TOP

Engine vibration at idle:

Check:

1.Vibration damper not assembled properly.
2.Vibration damper not adjusted properly.
3.Vibration damper loose on crankshaft.
4.Inoperative damper due to sticking.
5.Excessive timing gear or chain lash.
6.Timing gears or sprockets loose on camshaft or crankshaft.
7.Engine slightly loose in mountings.
8.Clutch linkage cross shaft not free or not properly lubricated.
9.Excessive clearance at front camshaft bearing.
10.Excessive clearance at front crankshaft bearing.
11.Eccentric timing gear - usually due to high key.
12.Loose timing chain.

BACK TO TOP

Engine vibration at high speed:

Check:

1.Engine missing at high speed.
2.Loose fan blade.
3.Unbalanced fan.
4.Uneven cylinder compression.
5.Distributor points not synchronized.
6.Engine mountings not adjusted properly.
7.Loose engine mountings.
8.Crankshaft which is sprung or unbalanced.
9.Engine support loose.
10.Scored pistons.
11.Insufficient clearances of internal engine parts.
12.Flywheel loose.
13.Fan belt worn or broken.

BACK TO TOP

Oil pump & distributor shaft noise:

Check:

1.End play in distributor drive shaft.
2.End play in oil pump drive shaft.
3.Oil pump not rigidly mounted.
4.Scullfed or damaged oil pump drive gears.
5.Worn or damaged oil pump and distributor driven gear.
6.Worn or damaged camshaft drive gear.
7.Oil pump drive and driven gears not meshed properly.
8.Couplings loose on shaft.
9.Excessive clearance of shaft in pump body.
10.Excessive clearance of shaft in distributor bracket bushings.
11.Hydraulic oil pump noise or rap.
12.Noise telegraphed through oil lines.
13.Relief valve clogged causing excessive oil pressure.

BACK TO TOP

Excessive fuel consumption:

Ignition:

1. Loose or corroded connections or terminals at the ammeter, ignition switch, coil or distributor.
2. Slight short in primary circuit wiring.
3. Poor low tension wire ground connection.
4. Loose, corroded or burned ignition switch contacts.
5. Faulty ammeter.
6. Loose or corroded high tension terminals or cable sockets.
7. Cracked, oil soaked, wet, chafed or worn high tension cable insulation.
8. Poor ground between coil and its mounting.
9. Poor ground between distributor and engine.
10. Breaker points not spaced properly.
11. Breaker points dirty, cracked, pitted or burned.
12. Breaker arm spring weak.
13. Breaker arm sticking.
14. Breaker arm insulating bushing worn.
15. Breaker arm rubbing block loose or badly worn.
16. Breaker arm plate loose or not properly grounded.
17. Breaker plate terminal posts loose.
18. Breaker pigtail lead wires loose or broken.
19. Ignition timing too late.
20. Distributor cap cracked, dirty or wet.
21. Distributor cap inserts bent, loose or badly burned.
22. Distributor shaft bent or worm.
23. Distributor shaft bushing or bearing loose or worn.
24. Distributor drive gear not timed properly with oil pump drive gear.
25. Vacuum spark advance diaphragm or spring broken.
26. Automatic spark advance plate stuck or loose.
27. Automatic advance governor springs weak or broken.
28. Automatic advance governor sticking or dirty.
29. Automatic advance governor pins worn.
30. Weak condenser.
31. Defective coil.
32. Cracked, wet or dirty coil tower.
33. Defective spark plugs.
34. Spark plugs operating too hot or too cold.
35. Spark plugs improperly gapped.
36. Spark plugs loose in cylinder head.
37. Fouled plugs due to damaged or ineffective gaskets.
38. Pre-ignition due to any source.
39. Weak battery.
40. Defective spark plugs or coil radio suppressors.

Fuel System:

1. Fuel level too high.
2. Excessive fuel pump pressure.
3. Float punctured and partially with fuel.
4. Float needle valve leaking due (o wear or dirt.
5. External carburetor leaks.
6. Accelerating pump improperly adjusted.
7. Economizer piston stuck in its cylinder.
8. Economizer valve stem sticking in its guide.
9. Economizer valve and accelerating pump control linkage not properly adjusted.
10. Internal leak due to accelerating pump valve not seating properly.
11. Economizer or power valve not seating properly causing internal leak.
12. Economizer valve operating too quickly.
13. Internal leak due to broken or cracked passages.
14. Use of metering jets, metering rods or nozzles which are too large.
15. Loose plugs or damaged gaskets at base of main discharge nozzles.
16. Manifold heat control valve held in closed position.
17. Dirty or restricted carburetor air cleaner.
18. Oil Level too high in oil bath type air cleaner.
19. Choke valve not fully open.
20. Carburetor adjusted for normal altitudes may have too rich a mixture at higher altitudes.
21. Automatic choke not functioning properly.
22. Fuel pump diaphragm leaking.
23. Abnormally fast engine idle speed.

Other Conditions:

1. Unequal or insufficient cylinder compression.
2. Restricted or partially clogged muffler, exhaust or tail pipe.
3. Engine overheated.
4. Excessive internal friction - due to insufficient engine clearances.
5. Connecting rods misaligned.
6. The use of expansion rings under piston rings - causing excessive friction.
7. The use of too heavy a grade engine oil.
8. Clutch slipping.
9. Tires under-inflated.
10. Rear axle misaligned.
11. Brakes dragging.
12. Bearings too tight in wheel, pinion, differential or transmission.
13. A gear ratio which is too low.
14. Incorrect valve timing.
15. Excessive front wheel toe-in or toe-out.
16. Scored pistons.
17. Loose or worn timing gears or chain sets up torsional vibrations, causing failure of automatic advance governor in distributor.
18. High speed operation for long periods.
19. Long period of idle operation.
20. Constant operation on short trips only.
21 Numerous starts and stops due to operation in congested traffic.
22. Failure to use cooling system thermostat or radiator covers, etc. in cold weather.
23. Sudden starting and stopping.
24. High speed driving.

BACK TO TOP

Starter not functioning correctly:

Check:

1. Battery in low state of charge.
2. Battery completely discharged.
3. Poor ground connection between battery and frame or from frame to engine.
4. Battery terminals badly corroded or loose.
5. Cable from battery to starter broken or terminal cracked.
6. Broken starter pinion.
7. Broken flywheel ring gear.
8. Sticking starter due to burred teeth on starter pinion or flywheel ring gear.
9. Broken Bendix spring.
10. Use of engine oil which is too heavy - especially in cold weather.
11. Starting switch not operating properly.
12. Starting switch not grounded properly.
13. Rotation of starter excessively resisted due to bent armature shaft, cracked or distorted housing, tight bearing, misaligned bearings, lack of lubrication sludge formation in starter drive' starter not aligned properly with engine.
14. Improper functioning of starter brushes due to loose brush connections, loose pigtails, brushes sticking in holders, bent brush holder arms, weak or broken brush springs, sticking brush holders, incorrect type of brushes, brushes worn too short.
15. Armature shorted.
16. Commutator surface dirty, burned, pitted excessively lubricated.
17. High mica between commutator segments due to worn commutator.
18. Brush ring set incorrectly or grounded.
19. Excessive brush spring tension - causing rapid wear of brushes and commutator.
20. Burned out, shorted or open-circuited field coils.
21. Worn bushings or bearings causing armature to drag against pole pieces.
22. Battery cables Undersized.
23. Winding thrown from armature.

BACK TO TOP

Generator / dynamo not charging:

Check for:

1. Engine idles too low on cars with free wheel and overdrive.
2. Incorrect size generator drive pulley.
3. Slipping belt.
4. Generator drive pulley loose on shaft.
5. Ammeter indicates no charging rate or incorrect charging rate.
6. Cutout relay points remaining open.
7. Generator regulator not operating properly.
8. Commutator not concentric.
9. Armature open-circuited, causing a low or no charging rate.
10. Armature grounded.
11. Generator pole piece loose, preventing easy rotation of armature.
12. Short circuit between commutator bars.
13. Bent or worn armature shaft, producing generator noise.
14. Brushes improperly seated or worn.
15. Incorrect type brushes being used.
16. Brush springs weak or broken.
17. High mica between commutator bars.
18. Commutator glazed, charred or dirty.
19. Brush holder arms sticking, probably caused by excessively worn brushes.
20. Field coils open-circuited, short circuited or burned out.
21. Brushes oily or soft due to excessive lubrication.

BACK TO TOP

High engine temperature:

Pre-Ignition:

1. Ignition timed too early.
2. Weak distributor automatic advance springs.
3. Combustion chamber with large carbon deposits.
4. Spark advance not operating upon acceleration.
5. Use of spark plugs which arc too hot.
6. Spark plug electrodes or insulators burned or carbonized.
7. Sharp metallic edges in combustion chamber.
8. Cylinder head gasket projecting into combustion chamber.
9. Excessively lean carburetor mixture.
10. Automatic heat control valve held in closed position.
11. Poor grade of fuel being used.
12. Stale fuel which has lost volatility.
13. Using a high compression cylinder head with standard fuel.
14. Hot engine valves caused by incorrect valve seat width.
15. Hot engine valves caused by insufficient valve tappet clearance.
16. Hot engine valves due to use of wrong type.
17. Hot engine valves due to their having thin edges.

Water Loss:

1. Radiator leak.
2. Any water hose leakage.
3. Leaky cooling system drain plug valve.
4. Leaky water pump.
5. Broken water pump gasket - or air cooling system gasket.
6. Cracked cylinder head or block causing an internal or external leak.
7. Water loss through overflow pipe especially when engine is overheated. 8. Radiator upper tank baffle plate loose.
9. Loose cylinder head cap screws or broken cylinder head gasket, allowing combustion gases to leak into the cooling system, causing overheating.
10. Loss of water at high speed due to an air leak at the water pump packing gland.
11. Loose or corroded water jacket cover plate.

Other Conditions:

1. Ignition timed too late.
2. Slipping fan belt.
3. Radiator core covered with dirt or heavy paint.
4. Radiator core surface restricted by license plate or emblems.
6. Heavy sludge or dirt accumulation in engine block.
7. Water manifold rusted, loose or damaged.
8. Engine thermostat not installed properly or not opening.
9. Collapsed or deteriorated water hose.
10. Water pump impeller loose on shaft.
11. Too much clearance between pump housing and impeller.
12. Use of certain types of anti-freeze solution during warm weather periods.
13. Water transfer holes in cylinder block or cylinder head restricted. 14. Cylinder head gasket installed in such a manner so as to restrict the flow of water.
15. Fan blades not pitched properly.
16. Using a rear axle gear ration which is too fast, or over sized tires in mountainous regions.
17. Brakes dragging.
18. Wheel bearings too tight.
19. Clutch slipping.
20. High frictional resistance in engine caused by: Insufficient oil circulation, Internal clearances of engine parts insufficient. Internal engine parts not aligned. Use of too heavy a grade engine oil.
21. High frictional resistance in power train transmitting units.
22. A floating foreign object in cylinder head which occasionally restricts water circulation.
23. Screen for hugs in front of radiator too fine.

BACK TO TOP

American Classic Car Parts

 

easyfindcarparts.com Home Page Home / Manufacturers List   Engine Troubleshooter Engine Troubleshooter   easyfindcarparts Contact Contact                                    EasyFindCarParts on Facebook

Copyright

easyfindcarparts.com - copyright symbol

easyfindcarparts.com