Engines 2 written final

what two primary sensors are the (something) catalytic converter

02 sensor and 02 sensor (pre and post)

for every 1 psi of cooling system pressure, coolant's boiling point is raised how many degrees

1 psi = 3 degrees

normal operating temp of a engine equipped with a what thermostat

185/205

A single overhead cam v8 has how many camshafts

2 camshafts

a good reading for cylinder leakage would be (how much percentage)

20 is acceptable, ideal is 10 or less

what is the mixture of coolant and water

50/50

A good running engine should have how much compression during a running compression test

60/90

If your upper radiator hose collapses when the engines cools, what is most likely the cause

A cap (radiatore cap)

all of these are functions of coolant, except

All of these are functions of coolant.

water pumps

Are driven by the engine crankshaft or camshaft

Tech A says a (radiator?????? i dont understand what tyler said here, but im pretty sure he said Radiator) should be inspected for leaks and (proper flow???) before installing a rebuilt engine Tech B overheating during slow city driving can be caused by defective fan

Both

Tech A says before removing an engine, the battery should be disconnected Tech B says to assist in reassembly, you should mark all unfamiliar hoses and wires in the engine compartment

Both

Tech A says that converter rattles when tapped with the mallet, it should be replaced Tech B says the root cause of the Converter failure should be diagnosed and repaired before replacing a Converter

Both

Tech A says that cooling fans are designed to draw air through radiator to aid in the heat transfer process Tech B says that drawing heat from the coolant transfers heat from through outside air into the radiator

Both

Tech A says the cracked exhaust manifold can affect engine operation Tech B says a leaking lower intake manifold can vacuum leak

Both

A thermostat can fail in which way?

Both (stuck open and stuck closed)

Which of these is true about thermostats

Both A and B (thermostats often cause overheating and temperature marked on the thermo stat should start to be fully open or right before)

A smoothly operating engine depends on ______________. a. high compression on all cylinders b. equal compression among cylinders c. cylinder compression levels above 100 psi (700 kPa) and within 70 psi (500 kPa) of each other d. compression levels below 100 psi (700 kPa) on most cylinders

Equal

True or False: Back pressure should be above 2 psi

False

Why do we pressurize automotive cooling system

Increase boiling point

Tech A says location of the Cat Converter is not important Tech B says that the Cat Converter should be positioned as far from engine as possible

Neither

cracked exhaust manifolds can cause false readings from what sensor

Oxygen sensor

Tech A says that an exhaust system contains cat converter, exhaust pipes, and a muffler Tech B says the entire exhaust system is supported by metal hangers that isolate noise

Tech A

Tech A says the purpose and function of the coolant system is to maintain proper engine operating temperature. Tech B says the water pump controls engine coolant temperature by opening at its rated temperature

Tech A

Tech A says that a compression test can be used to test the condition of connecting rods Tech B says a leakage test fills the cylinder with compressed air and engage in ????? percentage of leakage

Tech B

Tech A says use a steel gasket scrapper on aluminum engine parts Tech B says a plastic or wood scrapper on aluminum engine parts

Tech B

Customer complains heater works sometimes but sometimes only cold air comes out while driving

Tech B, coolant system is low on coolant

True or False: All cars should have cylinder leakage at 20% or less

True

True or False: Coolant leaking internally can be caused by gasket failure, cracked heads, cracked blocks, or a cracked intake manifold

True

some engines equipped with a timing belt, that belt may also drive what?

Water pump

a technician is performing a leakage test, the leakage on all cylinders is less than 10%, except for one which is 80%, what should the technician do next?

YOU DID IT WRONG, REPEAT TEST BECAUSE CYLINDER WAS NOT AT TOP DEAD CENTER

the upper portion of a two part intake manifold is often called

a plenum

which of these can cause cat failure

any of these/those

what color smoke would be a fuel smoke out of the exhaust

black

what can be done to prevent air from being trapped in the coolant system when the coolant is being replaced

bleed it with a vacuum bleeder or a bleeder funnel

what color smoke indicates oil being burnt

blue

Tech A says that a leaking head gasket can be tested by using a chemical tester Tech B says that a leaking head gasket can be found using an exhaust gas analyzer

both

Tech A says that some intake manifolds are plastic Tech A says that some intake manifolds are constructed in two parts

both

What do we call when air and fuel explode inside an engine

combustion

The ratio of the volume of a cylinder when a piston is at its lowest point (bottom dead center) to its volume when the piston is at its highest point (top dead center)

compression ration

what changes up and down motion into rotational motion

crankshaft

Coolant drained from the cooling system when replacing a thermostat or water pump should be ________.

dispose of properly or recycled

there is a picture of a piston, what stroke is this

exhaust

True or False: Using 100% coolant in the coolant system improves coolant system capacity

false

All of these are procedures (something idk) to diagnose the engine fault except

fuel level

vacuum readings showing when taking at idle speeds readings indicates that (shows vacuum reading at about 18 inches)

good condition

there are gasses going in the cat converter, what do they change to

h20 and C02

an intake manifold gasket has been replaced due to a vacuum leak, which of the following steps uses a scan tool to complete the job

idle relearn

The torque specifications for many plastic intake manifolds are in what unit?

inch pounds

why do we use a vacumm filler for coolant

it prevents air from entering the coolant system

Running compression test at idle should be equal; and Lower or Higher than cranking compression (static)

lower

A water pump can fail to provide the proper amount of coolant flow through the cooling system if what has happened?

the blades are warm or slipping on shaft

electric coolant cooling fans are typically commanded by what?

the pcm

coolant flowing through radiator is controlled by what

thermostat

coolant is a mix of

water and coolant

when replacing a timing belt, most manufacturers recommend what other part should be replaced as well?

water pump, tension-er, gaskets, idler and pully

low oil pressure light comes on when

when pressure is danger low

if a coolant system is operating at too cool of a temperature (too cold), the ends

will produce less efficiency

can a cat be harmed by coolant be dumped down the exhaust

yes