General Engine Diagnosis Part 1

routine

When an engine is using oil, check the crank case ventilation system as a _____

The head gasket has blown between the two cylinders

While doing a cylinder leak down test you hear air coming from the next cylinder over, what does this mean?

The torque converter bolts are loose

While in park you hear a slight knock but sounds behind the motor, what could it be?

o-ring

a leak from a fitting that is tight, may be from a damaged ______.

idle

at _____ a substantial amount of air enters the PCV valve.

02 sensors

What could you remove to identify a restricted exhaust system

Hydrocarbons

What element comes from the exaust and helps you pinpoint a faulty cylinder while doing tests.

Verify the customer complaint

What is the first step to working on vehicle.

PCV Valve

What should always be checked for good operation to prevent oil leaks.

The ignition and fuel systems

What two systems do you have to turn off to do a conpression test along with many other test

valvetrain noises

-bearings -rocker arms, shaft, ball and seat -pushrods -tappets and camshaft -timing gears and chain

Causes of black smoke

-leaking fuel pressure regulator diaphragm. -defective fuel injector. -electronic sensor misleading computer, adding more fuel than needed.

other engine noises

-loose or broken brackets -belt squeaking -spark knock - exhaust leak

crankshaft noises

-main bearings -connecting rod bearings -pistons -wrist pin -crankshaft end-play

half pint of fuel in 30 seconds

A good running motor will produce this within the fuel system

You have pinpointed the faulty hydraulic lifter

A hammer handle is pressed down on number 4 intake valve rocker and a slight ticking sound stops, what has happened?

Rotor button

Always check this while turning the motor to see if your timing chain or belt had broke.

white smoke

Any leak from the cooling system into the intake or combustion areas can cause ____

4 puffs

How many compression strokes do you allow while doing a compression test.

3-5

How much in. Hg of vacuum is acceptable while cranking the engine?

17-21

How much in. Hg vacuum is acceptable while running the engine?

spark plug doesnt fire

If this happens you should disconnect the coil wire from the cap and use a spark test.

Super over heat the coolant into a very fine vapor.

The convertor could do this and causes the internal coolant leak to be hid until it is very sever.

secondary circuit

The distributor, cap, rotor, wires, plug of the ignition system

pressure

The fuel system is always under ______. (on fuel injection systems, even when turned off)

primary circuit

The module and coil of the ignition system

Blown head gasket

The most common cause of white smoke

Black smoke

This is an indicator of an air fuel mixture that is too rich.

White smoke

This is an indicator that coolant is leaking into one or more cylinders and the engine is trying to burn the coolant.

cause of oil leaks

bad gaskets and seals.

Main bearing noise

caused by too much bearing clearance, which usually create a deep metallic knocking. When you increase rpm or engine load, the knocking usually increases in frequency.

hydraulic lifter noise

consistent ticking that occurs at a frequency slower than the engine rpm

crankshaft end play noise

deep knocking most obvious at idle, diminishes when a load is put on the crank shaft. Or if the clutch is disengaged on a manual vehicle.

piston noises

dull or muffled metallic rattle

piston pin noises

light but sharp metallic rapping at idle.

crank to easily

the timing belt or chain may have broken or jumped time.

valve stem seals

these are designed to keep normal amounts of lubrication oil from entering the combustion chamber.

excessive oil consumption

these are the common causes of _______. -oil leaks -guide/valve seal problems -piston ring problems

spark knock

uncontrolled combustion, sounds like a metallic ringing noise.

pressure testing the cooling system

watch the gauge needle for an indication of a leak.

Bearing noises

what is caused by too much clearance between parts or loss of oil pressure

fresh air

what must be able to enter the crank-case.

deceleration

when a vehicle suffers from worn valve guides and/or bad valve stem seals you'll see exhaust smoke during _____

entire

when excess oil is coming from the rings, the deposits on the spark plug accumulate on the ______ spark plug.

one side

when excess oil is coming from the valve guide, the oil tends to deposit on just _______ of the spark plug

tip of craknshaft

you can verify if excessive crankshaft end play by fitting a dial indicator to the ______

before road test

you should always visually inspect the vehicle for fuel/oil/coolant leaks, loose/cracked/glazed/frayed belts

inlet

you should feel a strong pressureif you pull the PCV valve out of its grommet with the engine idling, you should feel a strong suction at the valves _____.