Chapter 20 Engine

In today's vehicles, most automotive cooling systems are pressurized at ____ psi.

13-21

When engine temperature gets hot enough (approximately _____), the thermo-control switch will close and either send power directly to the fan or cause a relay to be activated, which turns on the fan.

215° F

What percentage of the original energy is used for powering the vehicle and its accessories?

25% - 30%

For each "pound" (psi) of pressure applied to the cooling system, the coolant's boiling point is increased by:

3.0° F.

Approximately what percentage of heat energy is wasted by the cooling system, which prevents overheating of the engine components?

33%

Surge tanks:

Are usually mounted at the highest point of the cooling system.

Coolant flow through a piston engine is being discussed. Technician A says that a piston engine coolant flow is considered a normal flow system if the flow from the water pump goes through the engine block, then the cylinder heads. Technician B says that a piston engine's coolant flow is considered a reverse flow system if the flow from the water pump goes through the cylinder heads first, then the engine block. Who is correct?

Both A and B

The water pump in a vehicle's cooling system uses a:

Centrifugal pump.

The type of heat transfer where heat is transferred from one solid to another is called:

Conduction.

_________ provide power to drive the water pump and other accessories on the front of the engine.

Drive belts

In a typical reverse-flow cooling system, after the coolant moves through the cylinder head, it finds its way to the _______, and then returns to the radiator.

Engine block

The device that is attached to the radiator to help draw air through the entire radiator is called the:

Fan shroud

The _____ consists of many air doors, which are plastic or metal flaps that seal off parts of the air box to control airflow.

Heater box

The _______ controls the flow of coolant to the heater core to control the temperature of the air desired by the operator.

Heater control valve

Heat is transferred from areas of:

Higher temperature to lower temperature.

A proper mixture of antifreeze and water:

Increases the boiling point of the coolant.

Heater cores are typically constructed from all of the following EXCEPT:

Iron.

The heater box air doors can be moved by the following methods EXCEPT:

Mechanical lever.

Technician A states that the cooling system of the rotary engine is very different from the piston engine's cooling system. Technician B states that water flows from the water pump to the radiator, then into the rotor housing. Who is correct?

Neither Technician A nor Technician B

The cooling system of the rotary engine is _______ the piston engine's cooling system.

Not much different from

Centrifugal force is a force pulling ______ on a ______ body.

Outward; rotating

Because the _______ can create substantial power, hydraulic driven fans can be used to draw a large amount of air through the radiator.

Power steering pump

The cooling system device that maintains pressure in order to raise the boiling point of the coolant is called the:

Pressure Cap

A spring-loaded automatic tensioner is typically used with ________.

Serpentine accessory belts

A ________, also called a multi-groove V-belt, has a flat profile with a number of small V-shaped grooves running lengthwise along the inside of the belt.

Serpentine belt

Some radiator hoses, especially lower hoses, have a _______ inside to keep the hose from collapsing during heavy acceleration when the water pump is drawing a lot of water from the radiator.

Spiral wire

The _______ has coolant constantly running through it and is usually located higher than the top of the radiator.

Surge tank

Technician A says core plugs are used to plug the holes that are used in the manufacturing process for the engine block. Technician B says that core plugs are designed to pop out of the block if the coolant freezes. Who is correct?

Tech A

Technician A says that electric cooling fans save energy because they only come on when needed. Technician B says that engine-driven fans are more fuel efficient than electric fans. Who is correct?

Tech A

Technician A says that some drive belts are of a stretch fit design and are not adjustable. Technician B says that automatic belt tensioners never wear out. Who is correct?

Tech A

Technician A says that the design of a surge tank system helps to purge air from the cooling system. Technician B says that the overflow tank adds coolant to the radiator when the engine is hotter than normal. Who is correct?

Tech A

Technician A states that about 33% of the heat energy created is wasted by being dumped straight out of the exhaust to the atmosphere. Technician B states that 33% of the heat energy created is wasted by internal friction and from radiating off hot engine components straight to the atmosphere. Who is correct?

Tech A

Technician A says that electric fans should run continuously to ensure proper engine cooling. Technician B says that a fan is usually not needed at vehicle speeds above 35 mph. Who is correct?

Tech B

Technician A says that green coolant that has been around since the 1930s is categorized as a HOAT coolant. Technician B says that HOAT stands for hybrid organic acid technology. Who is correct?

Technician B

The __________ regulates coolant flow to the radiator.

Thermostat

The liquid with the best available cooling properties because of it's ability to absorb large amounts of heat is:

Water.

Thermostats use a ________ to open the valve to allow coolant flow.

Wax pellet

Most water pumps have a small ______ that sits between the seal and the bearing, and vents any coolant that leaks past the seal to be drained to the outside of the engine.

Weep hole

All of the following statements are true of a thermostat EXCEPT:

When the engine is cold, the valve is open; when hot, the valve is closed.

An overflow tank is used to:

catch coolant that is released by the radiator cap when the coolant heats up