Transcript Lesson 3- Lubrication Cooling
Slide 1
Engine Lubrication & Cooling
Slide 2
In the last lesson we learned about the
incredible temperatures and speeds at
which engine parts operate. An engine
could not run for very long without some
way of reducing the friction between
moving parts and controlling the
temperature of engine components.
In this lesson we will learn how oil and coolant
perform these important tasks for us, and
what we can do—as car owners—to
ensure that they will continue to do so for
a long time.
Slide 3
Slide 4
Pistons, valves, and all of the moving parts in the engine would get
very hot and fail quickly if they were actually rubbing against each
other inside the engine. Fortunately, they are not. All of the moving
parts inside of your engine have a very thin film of oil between them,
keeping metal from ever contacting metal.
When the engine is not
running, all of the oil sits in
the bottom of the engine in
the “oil pan.” Once the car
is started, an oil pump
begins to deliver oil to the
rest of the engine.
Oil is pumped throughout
the engine, so that it is
constantly circulating and
lubricating all of the moving
components.
Oil Pan
Slide 5
Oil’s job is a tough one. Today’s oils contain many additives
that help them to hold up under the extreme
conditions they are subjected to. However, even the
best oils break down with time. They become
contaminated with dirt, moisture, and fuel—all of
which are poor lubricants!
How do dirt, moisture, and fuel get into my oil?
•Dirt comes from dust in the air taken into the engine on the intake stroke, which gets past the piston into the oil
•Moisture also comes from the incoming air; it gets into the warm engine and condenses when it cools down
•Small amounts of fuel also get past the pistons and end up in the oil
For these reasons, old oil needs to be drained and
replaced with new oil regularly. Oil that is not
changed will start to turn into “sludge,” plugging
critical oil passages. Additionally, over time, moisture
in the oil causes corrosive acids to form, which will
begin to damage internal engine parts if the oil isn’t
changed.
When the oil is changed, the oil filter should also be replaced. This filter is
usually located on the side of the engine and helps to trap some of the
harmful particles that might be circulating in your oil.
To learn more about changing oil, return to I-learn now and watch the
video entitled “Changing Oil.” Even people who have changed their
own oil before will learn some new things from this video.
Slide 6
This picture shows
sludge on an
engine’s timing
chain and
camshafts.
This is a result of
not changing the
oil often enough.
When oil becomes
thick like this,
severe engine
damage has
probably already
occurred.
Slide 7
This photograph shows
a piston that was
removed from an
engine that was
neglected. The owner
forgot to change his
engine oil for over a
year.
Scoring that occurred when this piston and
the cylinder wall were contacting each other
without a film of oil between them.
The scoring on the side
of the piston give us an
indication of how much
friction and heat are
developed when an
engine lacks plenty of
good, clean oil.
Slide 8
People are often confused about how often to change their engine oil.
Many owner’s manual maintenance schedules call for oil change
intervals that range from every 5,000 miles to every 12,000 miles. Yet,
you will hear others say it should be changed every 3,000 miles or every
3 months.
Your owner’s manual can usually be trusted! If your owner’s manual calls for
a very long interval between oil changes (such as 10,000 miles or more),
make sure to read the fine print. This interval is likely only valid if you are
using a specific brand of synthetic oil and under normal or “ideal” driving
conditions only. If you drive your car under any of the following conditions,
your oil becomes contaminated and breaks down much faster:
What this means for you: nearly everyone drives their car under one or more of these
severe conditions. Therefore, you should change your oil frequently, regardless of how
many miles you drive. The safest recommendation is to change it every 5,000 miles or every
6 months (whichever comes first)—if you want your engine to last! If your engine does fail, it
will cost you $3,000 - $8,000 to repair it; changing your oil is much less expensive!
Slide 9
Checking your oil is just as important as
changing your oil. In the first slide of this
lesson we learned that keeping your oil full
and keeping it changed are the two most
critical things you can do for your engine.
How often should you check your oil level?
You should check your oil level every week. Many people make a habit
of doing this each time they buy fuel. But, no matter when you choose
to check your oil, the important thing is that you are doing it! The oil
level in your engine drops for two reasons:
1-Every engine burns some oil during the combustion process
2-Many engines leak some oil past the seals
Since an engine can suddenly—and without warning—begin to burn or
leak more oil, watch for signs of these problems such as smoke coming
from the exhaust pipe or drops of oil on the ground. Check your oil level
immediately if you see this. But remember that even brand new engines
consume some oil and may run low if not checked regularly.
Slide 10
To check your oil, follow these steps:
1. Make sure the engine has been off for at least 2-3 minutes
2. Open the hood and locate the engine oil dipstick (refer to your
owner’s manual to make sure you are using the correct dipstick)
3. Pull the dipstick out and wipe if off with a rag
4. Reinsert the dipstick, making sure it is fully seated
5. Remove the dipstick again and look for the oil level on the dipstick.
What are the marks on the dipstick for?
On the dipstick you will likely see a “full” mark
and an “add” or “low” mark. The oil should be
to the “full” mark. It takes exactly one quart of
oil to raise it from the “add” mark to the “full”
mark.
The color of the oil is also an indicator of its
condition. The picture on the left shows used
oil (at the “add” mark) just before it was
changed. The oil on the dipstick to the right is
new—just after an oil change.
“Full” mark
“Add” mark
Slide 11
If you need to add oil, determine the correct type of oil, locate & remove
the engine oil fill cap, and pour it in (you may need a funnel). Be
careful not to over-fill it. If the oil level gets too high in the oil pan, the
crankshaft and pistons can begin to splash in the oil, causing it to
become foamy and aerated. Over-filling an engine with oil can damage
your engine just as easily as letting it get too low can.
Engine oil
fill cap
Engine oil dipstick
Slide 12
There are two important considerations to make when choosing the oil you will use in your car:
1. It should be the correct viscosity and type for your car
2. The oil should be API certified
(We will discuss what both of these mean in the next two slides)
There are some other factors that do not matter and are personal preferences only:
•The brand of the oil
•Whether it is synthetic or conventional oil (some cars call for a specific type of
synthetic oil. Very high quality synthetic oils do last longer and provide better
protection, but as long as you change it often, conventional oil will suffice)
Slide 13
Viscosity is a measurement of how easily oil flows at a given temperature. Oil acts a lot like
maple syrup—if it is warm, it is thin and flows easily, but if it has been in the refrigerator, it is
thick and flows slowly.
Oil is assigned a weight based on its viscosity. The lower the number, the thinner the oil will
be. For example, a 40 weight oil is a lot thinner than a 75 weight oil, but a 10 weight oil is
even thinner than them both and will flow more easily in cold temperatures.
Today’s engine oils are “multi-viscosity” oils—for example 5W-30 or 10W-40. If an oil has a
viscosity, or weight, of 5W-30, it is formulated to act as a 5 weight oil in the winter and a 30
weight oil in the summer. Because of this, the oil will be thin enough to flow in the winter, but
thick enough to provide lubrication in the summer. Therefore, the same oil can usually be
used all year long.
It is important to use oil
with the right viscosity
for your engine!
While you may hear a lot of different things and people
may try to sell you many different kinds of oil, the
safest advice is this: Always use the type and
weight of oil called for in your owner’s manual.
Slide 14
The American Petroleum Institute (API) sets standards for motor oil. If a
motor oil meets these minimum standards, one or both of the seals
shown below will appear on the bottle. If it doesn’t have these seals—
don’t buy it!
Slide 15
Used motor oil should be taken to a facility that will recycle it. If it is
dumped on the ground or down a drain it can have detrimental
effects on the environment.
One gallon of used motor oil (about the amount
obtained from one oil change) can contaminate up to 1 million gallons of
drinking water!
Most auto parts stores will take
your used oil for free. If you
choose to change your own oil,
just put the used oil in a
container (like an empty milk
carton) and drop it off to them.
These facilities will make sure
your oil is recycled or disposed
of properly.
Slide 16
Your car has a sensor on the engine that constantly monitors your oil
pressure. It is making sure that the oil pump is pumping the oil with
enough pressure to reach all of the parts of your engine.
Most cars have an oil pressure light on the dash. A few cars have
an oil pressure gauge instead. Either way, your dash instruments
should alert you if the your engine’s oil pressure gets too low.
Your oil pressure light should be on whenever the engine is not running, but should turn off within a
few seconds of starting the car. If the light remains on or comes back on while the engine is running,
pull over and shut the engine off! Check your oil level first. If it is fine, get your car to a repair shop
and have it checked out. By turning the engine off quickly, you may just save your engine!
Slide 17
When it is very cold outside,
your oil is also cold.
Most of your engine wear
happens right after startup on
these cold days because the oil
cannot reach or lubricate all of
the moving parts very quickly.
Here are some tips to minimize
engine wear and help your car
to last longer:
Start your engine & wait until the oil light on your dash turns off
Drive away slowly—don’t rev the engine or accelerate quickly
Avoid idling the engine for long periods (letting the engine idle while the heater
warms up is not recommended)
Never drive your car until your windows are completely clear of ice and snow!
If you have a garage, keep your car parked there; garages stay warmer
When your car is idling, the oil pressure is low. When the oil is cold, it is thick and doesn't lubricate the engine very well. Combine
both of those factors--idling when the oil is cold--and it's twice as hard on your engine.
Slide 18
Slide 19
The cooling system does exactly what you would expect—it helps to
control the temperature of the engine. It performs these two basic
functions:
1. The cooling system keeps the engine from
getting too hot—the engine would be
permanently damaged if it overheated by even
a few degrees.
2. The cooling system helps the engine to
warm up quickly once it is started. This is
important because the engine doesn’t run
efficiently until it is warmed up.
Slide 20
Coolant (also called antifreeze) circulates
around the outside of the engine’s
cylinders in “water jackets.”
Cylinder
Remember—the cylinders are where the pistons travel
up and down and where the combustion takes place.
The coolant absorbs heat from the
combustion process and carries it away to
the radiator. The radiator is usually near
the front of the car where air passes
through it and cools off the hot coolant.
Once the coolant is cooled off, it returns
to the engine to absorb more heat. This
process continues as long as the engine is
running.
Water Jacket
Slide 21
When you first start your car, the
Pressure Cap
water pump begins turning and
circulates the coolant around in
the water jackets. However,
Fan pulls air
until the engine and coolant get
through radiator
warmed up, a thermostat stays
closed and blocks the coolant
from flowing to the radiator. This
keeps the warming coolant in the
engine and helps the engine to
warm up quickly.
As soon as the coolant is warm
enough, the thermostat opens
and the hot coolant begins to flow
to the radiator.
When the car is moving down the
road, air flows through the
radiator, cooling this hot coolant.
But, if the car is not moving (or is
driving slowly), a fan turns on and
pulls additional air through the
radiator, preventing the coolant
from getting too hot.
Radiator
Thermostat Regulates
flow of coolant
Water Pump
Circulates coolant
Cylinders
Water
Jacket
The pressure cap (also called a radiator cap) seals
the system, allowing pressure to build as the coolant
heats up and expands.
Go back to I-learn now and watch the video entitled
“How the Cooling System Works”
Slide 22
As we just mentioned, the pressure cap is designed to keep the cooling
system under pressure. As the coolant heats up, it expands. Because
the cap seals the cooling system, this expansion creates pressure.
Increased pressure works in our favor because it increases the boiling
point of the coolant. If the coolant were to boil, it would vaporize and
would no longer be able to circulate or conduct heat away from the
engine.
Therefore, the pressure cap is an
indispensible part of the cooling system,
and a faulty pressure cap can easily cause
the engine to overheat.
Caution: Never open the pressure cap
when it is warm or hot. The hot, pressurized
coolant could cause severe burns. Wait
until it has cooled down!
Slide 23
Today’s cars all have some type of coolant reservoir aside from the radiator.
It is usually a clear or opaque bottle somewhere under the hood with “min”
and “max” marks on the side of it. But what is it for?
As the coolant expands, it
eventually may build
enough pressure to
bypass the pressure cap.
If it does this, it needs a
place to go.
The reservoir takes on the
expanding coolant and
holds it until it cools back
down and contracts back
into the radiator.
Go back to I-learn now
and watch the video
entitled, “Pressure Caps.”
Slide 24
In early automobile history, people used water to cool their engines.
However, water had several drawbacks—it freezes at 32°F, it boils at
212°F, and it causes the insides of the engine and radiator to rust.
On a cold night, if water were to freeze inside your engine and radiator, it would
expand and crack your engine block, damaging it beyond repair.
These problems and others prompted
the development of “antifreeze,” a
chemical that is added to water,
creating a mixture with a lower
freezing point and a higher boiling
point.
This mixture is called coolant.
Today’s coolants also prevent
corrosion and protect the inside of
the cooling system from rust.
Slide 25
As a car owner, you’ll be glad to know that the cooling system
requires very little maintenance. However, it cannot be neglected,
either! Here is a list of things you should do; each of them will be
discussed in a subsequent slide:
Check your coolant level regularly
Have your coolant changed at the correct interval
(specified in your owner’s manual)
Watch the temperature gauge or warning light on your
dash
Occasionally check your hoses and belts
Keep the radiator clean of bugs, leaves & dirt
Slide 26
Because it is so easy, there is no excuse to not check your coolant level
each time you open your hood to check your oil. Simply glance at the
coolant reservoir and make sure the level is somewhere between the
“min” and “max” marks. If it is low, add some coolant and check for
leaks. While it is normal for a very small amount of coolant to
evaporate over time, if you have to add coolant more than once a year,
you probably have a leak that needs to be addressed.
You should not have to open the pressure cap to check the
coolant level or add coolant unless there is none in the
reservoir. If you see none in the reservoir, it is time to open
the pressure cap (if it is not hot) and find out if there is any in
the radiator!
Coolant in the radiator
Slide 27
The answer to this question is simple: whenever your owner’s manual
says that you should. Coolant breaks down over time. It looses its ability
to protect from freezing, boiling, and corrosion. If coolant is not changed
on time, it can cause expensive damage to the engine, radiator, and other
components. No matter how much its costs to change your
coolant, it costs less than it would to replace your engine.
There are different types of coolants used in different cars. Because of
this, the service interval may range from “every 24,000 miles” to “every
150,000 miles.”
If the wrong coolant is ever added to your system, it may greatly reduce
the life expectancy of your coolant—so make sure you use the correct
fluid!
It is recommended that you take your car to a professional for cooling
system services and flushes. If you choose to do it yourself, remember
that roughly half of your coolant is in your radiator and half is in your
engine. Draining the radiator alone will only get half of it!
Slide 28
Depending on your car, your dash should have a
temperature gauge, a temperature warning
light, or both. If you have a gauge, the needle
should move to the middle of the gauge (about
210°F) as the car warms up, and never get any
higher than this.
“Danger Zone”—do
not continue to drive
If you have a warning light, it should come on
when you first turn your key on, then shut off
once you start your car. If it ever comes back
on while you are driving, the engine is too hot.
“Danger Zone”—do
not continue to drive
Temperature
Warning light
Temperature gauge
Slide 29
Belts
It is a good idea to periodically inspect
your belts and hoses. The belts keep
your water pump and other accessories
turning. If it breaks, the pump will not
circulate the coolant and the engine will
overheat.
Check your belts at each oil change,
looking for cracking and chunks that are
breaking off. Belts typically need to be
changed about every 60,000 miles
Cracking
Chunking
Hoses
Hoses transport the coolant from the
engine to the radiator and back. At the
same time you are checking your belts,
check your hoses for bulging, softness,
leaks, or other indications of
deterioration. Have them replaced at the
first sign of trouble.
Bulging (feels soft)
Leaking
Slide 30
Another way you can keep your cooling
system operating at its best is to
periodically check the radiator to make
sure it isn’t plugged with bugs, dirt,
leaves, or other debris.
A bug or two is not a problem, but if
buildup begins to block airflow through
the radiator, the coolant will not be
able to cool off enough and the engine
may overheat.
When cleaning the radiator, use water,
compressed air, or a very soft brush
(most auto parts stores sell an
inexpensive tool you can use). Using a
metal object to clean the radiator may
result in punctures and leaks.
Slide 31
In the past, all cars used the same
antifreeze/coolant. Not today! As mentioned
earlier, there are many different types of
coolants and they are not all the same. Even
coolants that are the same color are not
necessarily interchangeable.
The simplest way to determine which type of
coolant to use in your car is . . . you guessed
it . . . look in your owner’s manual.
Typically, coolant should be checked and added at the reservoir.
Unless you buy it pre-mixed, coolant needs to
be mixed with water before it is added to the
system. Neither coolant nor water alone has a
sufficient freezing or boiling point. However, a
proper mixture of both fluids does.
Remember this! For most climates, the recommended ratio of coolant to water is
1:1. This means that the coolant you use should be composed of 50% water and 50%
antifreeze, which provides freeze protection down to -35°F.
Slide 32
In this lesson we have learned about the indispensible roles of the
lubrication and cooling systems in your automobile. Without them,
the engine could not operate for very long.
Both of these systems require some periodic maintenance. Whether
you choose to do this maintenance yourself or have someone else do
it, becoming an educated owner is the first step to extending the life
of your engine and car.
Remember: keeping your oil and your coolant full and changed on
schedule is the most important thing you can learn from this lesson!
Engine Lubrication & Cooling
Slide 2
In the last lesson we learned about the
incredible temperatures and speeds at
which engine parts operate. An engine
could not run for very long without some
way of reducing the friction between
moving parts and controlling the
temperature of engine components.
In this lesson we will learn how oil and coolant
perform these important tasks for us, and
what we can do—as car owners—to
ensure that they will continue to do so for
a long time.
Slide 3
Slide 4
Pistons, valves, and all of the moving parts in the engine would get
very hot and fail quickly if they were actually rubbing against each
other inside the engine. Fortunately, they are not. All of the moving
parts inside of your engine have a very thin film of oil between them,
keeping metal from ever contacting metal.
When the engine is not
running, all of the oil sits in
the bottom of the engine in
the “oil pan.” Once the car
is started, an oil pump
begins to deliver oil to the
rest of the engine.
Oil is pumped throughout
the engine, so that it is
constantly circulating and
lubricating all of the moving
components.
Oil Pan
Slide 5
Oil’s job is a tough one. Today’s oils contain many additives
that help them to hold up under the extreme
conditions they are subjected to. However, even the
best oils break down with time. They become
contaminated with dirt, moisture, and fuel—all of
which are poor lubricants!
How do dirt, moisture, and fuel get into my oil?
•Dirt comes from dust in the air taken into the engine on the intake stroke, which gets past the piston into the oil
•Moisture also comes from the incoming air; it gets into the warm engine and condenses when it cools down
•Small amounts of fuel also get past the pistons and end up in the oil
For these reasons, old oil needs to be drained and
replaced with new oil regularly. Oil that is not
changed will start to turn into “sludge,” plugging
critical oil passages. Additionally, over time, moisture
in the oil causes corrosive acids to form, which will
begin to damage internal engine parts if the oil isn’t
changed.
When the oil is changed, the oil filter should also be replaced. This filter is
usually located on the side of the engine and helps to trap some of the
harmful particles that might be circulating in your oil.
To learn more about changing oil, return to I-learn now and watch the
video entitled “Changing Oil.” Even people who have changed their
own oil before will learn some new things from this video.
Slide 6
This picture shows
sludge on an
engine’s timing
chain and
camshafts.
This is a result of
not changing the
oil often enough.
When oil becomes
thick like this,
severe engine
damage has
probably already
occurred.
Slide 7
This photograph shows
a piston that was
removed from an
engine that was
neglected. The owner
forgot to change his
engine oil for over a
year.
Scoring that occurred when this piston and
the cylinder wall were contacting each other
without a film of oil between them.
The scoring on the side
of the piston give us an
indication of how much
friction and heat are
developed when an
engine lacks plenty of
good, clean oil.
Slide 8
People are often confused about how often to change their engine oil.
Many owner’s manual maintenance schedules call for oil change
intervals that range from every 5,000 miles to every 12,000 miles. Yet,
you will hear others say it should be changed every 3,000 miles or every
3 months.
Your owner’s manual can usually be trusted! If your owner’s manual calls for
a very long interval between oil changes (such as 10,000 miles or more),
make sure to read the fine print. This interval is likely only valid if you are
using a specific brand of synthetic oil and under normal or “ideal” driving
conditions only. If you drive your car under any of the following conditions,
your oil becomes contaminated and breaks down much faster:
What this means for you: nearly everyone drives their car under one or more of these
severe conditions. Therefore, you should change your oil frequently, regardless of how
many miles you drive. The safest recommendation is to change it every 5,000 miles or every
6 months (whichever comes first)—if you want your engine to last! If your engine does fail, it
will cost you $3,000 - $8,000 to repair it; changing your oil is much less expensive!
Slide 9
Checking your oil is just as important as
changing your oil. In the first slide of this
lesson we learned that keeping your oil full
and keeping it changed are the two most
critical things you can do for your engine.
How often should you check your oil level?
You should check your oil level every week. Many people make a habit
of doing this each time they buy fuel. But, no matter when you choose
to check your oil, the important thing is that you are doing it! The oil
level in your engine drops for two reasons:
1-Every engine burns some oil during the combustion process
2-Many engines leak some oil past the seals
Since an engine can suddenly—and without warning—begin to burn or
leak more oil, watch for signs of these problems such as smoke coming
from the exhaust pipe or drops of oil on the ground. Check your oil level
immediately if you see this. But remember that even brand new engines
consume some oil and may run low if not checked regularly.
Slide 10
To check your oil, follow these steps:
1. Make sure the engine has been off for at least 2-3 minutes
2. Open the hood and locate the engine oil dipstick (refer to your
owner’s manual to make sure you are using the correct dipstick)
3. Pull the dipstick out and wipe if off with a rag
4. Reinsert the dipstick, making sure it is fully seated
5. Remove the dipstick again and look for the oil level on the dipstick.
What are the marks on the dipstick for?
On the dipstick you will likely see a “full” mark
and an “add” or “low” mark. The oil should be
to the “full” mark. It takes exactly one quart of
oil to raise it from the “add” mark to the “full”
mark.
The color of the oil is also an indicator of its
condition. The picture on the left shows used
oil (at the “add” mark) just before it was
changed. The oil on the dipstick to the right is
new—just after an oil change.
“Full” mark
“Add” mark
Slide 11
If you need to add oil, determine the correct type of oil, locate & remove
the engine oil fill cap, and pour it in (you may need a funnel). Be
careful not to over-fill it. If the oil level gets too high in the oil pan, the
crankshaft and pistons can begin to splash in the oil, causing it to
become foamy and aerated. Over-filling an engine with oil can damage
your engine just as easily as letting it get too low can.
Engine oil
fill cap
Engine oil dipstick
Slide 12
There are two important considerations to make when choosing the oil you will use in your car:
1. It should be the correct viscosity and type for your car
2. The oil should be API certified
(We will discuss what both of these mean in the next two slides)
There are some other factors that do not matter and are personal preferences only:
•The brand of the oil
•Whether it is synthetic or conventional oil (some cars call for a specific type of
synthetic oil. Very high quality synthetic oils do last longer and provide better
protection, but as long as you change it often, conventional oil will suffice)
Slide 13
Viscosity is a measurement of how easily oil flows at a given temperature. Oil acts a lot like
maple syrup—if it is warm, it is thin and flows easily, but if it has been in the refrigerator, it is
thick and flows slowly.
Oil is assigned a weight based on its viscosity. The lower the number, the thinner the oil will
be. For example, a 40 weight oil is a lot thinner than a 75 weight oil, but a 10 weight oil is
even thinner than them both and will flow more easily in cold temperatures.
Today’s engine oils are “multi-viscosity” oils—for example 5W-30 or 10W-40. If an oil has a
viscosity, or weight, of 5W-30, it is formulated to act as a 5 weight oil in the winter and a 30
weight oil in the summer. Because of this, the oil will be thin enough to flow in the winter, but
thick enough to provide lubrication in the summer. Therefore, the same oil can usually be
used all year long.
It is important to use oil
with the right viscosity
for your engine!
While you may hear a lot of different things and people
may try to sell you many different kinds of oil, the
safest advice is this: Always use the type and
weight of oil called for in your owner’s manual.
Slide 14
The American Petroleum Institute (API) sets standards for motor oil. If a
motor oil meets these minimum standards, one or both of the seals
shown below will appear on the bottle. If it doesn’t have these seals—
don’t buy it!
Slide 15
Used motor oil should be taken to a facility that will recycle it. If it is
dumped on the ground or down a drain it can have detrimental
effects on the environment.
One gallon of used motor oil (about the amount
obtained from one oil change) can contaminate up to 1 million gallons of
drinking water!
Most auto parts stores will take
your used oil for free. If you
choose to change your own oil,
just put the used oil in a
container (like an empty milk
carton) and drop it off to them.
These facilities will make sure
your oil is recycled or disposed
of properly.
Slide 16
Your car has a sensor on the engine that constantly monitors your oil
pressure. It is making sure that the oil pump is pumping the oil with
enough pressure to reach all of the parts of your engine.
Most cars have an oil pressure light on the dash. A few cars have
an oil pressure gauge instead. Either way, your dash instruments
should alert you if the your engine’s oil pressure gets too low.
Your oil pressure light should be on whenever the engine is not running, but should turn off within a
few seconds of starting the car. If the light remains on or comes back on while the engine is running,
pull over and shut the engine off! Check your oil level first. If it is fine, get your car to a repair shop
and have it checked out. By turning the engine off quickly, you may just save your engine!
Slide 17
When it is very cold outside,
your oil is also cold.
Most of your engine wear
happens right after startup on
these cold days because the oil
cannot reach or lubricate all of
the moving parts very quickly.
Here are some tips to minimize
engine wear and help your car
to last longer:
Start your engine & wait until the oil light on your dash turns off
Drive away slowly—don’t rev the engine or accelerate quickly
Avoid idling the engine for long periods (letting the engine idle while the heater
warms up is not recommended)
Never drive your car until your windows are completely clear of ice and snow!
If you have a garage, keep your car parked there; garages stay warmer
When your car is idling, the oil pressure is low. When the oil is cold, it is thick and doesn't lubricate the engine very well. Combine
both of those factors--idling when the oil is cold--and it's twice as hard on your engine.
Slide 18
Slide 19
The cooling system does exactly what you would expect—it helps to
control the temperature of the engine. It performs these two basic
functions:
1. The cooling system keeps the engine from
getting too hot—the engine would be
permanently damaged if it overheated by even
a few degrees.
2. The cooling system helps the engine to
warm up quickly once it is started. This is
important because the engine doesn’t run
efficiently until it is warmed up.
Slide 20
Coolant (also called antifreeze) circulates
around the outside of the engine’s
cylinders in “water jackets.”
Cylinder
Remember—the cylinders are where the pistons travel
up and down and where the combustion takes place.
The coolant absorbs heat from the
combustion process and carries it away to
the radiator. The radiator is usually near
the front of the car where air passes
through it and cools off the hot coolant.
Once the coolant is cooled off, it returns
to the engine to absorb more heat. This
process continues as long as the engine is
running.
Water Jacket
Slide 21
When you first start your car, the
Pressure Cap
water pump begins turning and
circulates the coolant around in
the water jackets. However,
Fan pulls air
until the engine and coolant get
through radiator
warmed up, a thermostat stays
closed and blocks the coolant
from flowing to the radiator. This
keeps the warming coolant in the
engine and helps the engine to
warm up quickly.
As soon as the coolant is warm
enough, the thermostat opens
and the hot coolant begins to flow
to the radiator.
When the car is moving down the
road, air flows through the
radiator, cooling this hot coolant.
But, if the car is not moving (or is
driving slowly), a fan turns on and
pulls additional air through the
radiator, preventing the coolant
from getting too hot.
Radiator
Thermostat Regulates
flow of coolant
Water Pump
Circulates coolant
Cylinders
Water
Jacket
The pressure cap (also called a radiator cap) seals
the system, allowing pressure to build as the coolant
heats up and expands.
Go back to I-learn now and watch the video entitled
“How the Cooling System Works”
Slide 22
As we just mentioned, the pressure cap is designed to keep the cooling
system under pressure. As the coolant heats up, it expands. Because
the cap seals the cooling system, this expansion creates pressure.
Increased pressure works in our favor because it increases the boiling
point of the coolant. If the coolant were to boil, it would vaporize and
would no longer be able to circulate or conduct heat away from the
engine.
Therefore, the pressure cap is an
indispensible part of the cooling system,
and a faulty pressure cap can easily cause
the engine to overheat.
Caution: Never open the pressure cap
when it is warm or hot. The hot, pressurized
coolant could cause severe burns. Wait
until it has cooled down!
Slide 23
Today’s cars all have some type of coolant reservoir aside from the radiator.
It is usually a clear or opaque bottle somewhere under the hood with “min”
and “max” marks on the side of it. But what is it for?
As the coolant expands, it
eventually may build
enough pressure to
bypass the pressure cap.
If it does this, it needs a
place to go.
The reservoir takes on the
expanding coolant and
holds it until it cools back
down and contracts back
into the radiator.
Go back to I-learn now
and watch the video
entitled, “Pressure Caps.”
Slide 24
In early automobile history, people used water to cool their engines.
However, water had several drawbacks—it freezes at 32°F, it boils at
212°F, and it causes the insides of the engine and radiator to rust.
On a cold night, if water were to freeze inside your engine and radiator, it would
expand and crack your engine block, damaging it beyond repair.
These problems and others prompted
the development of “antifreeze,” a
chemical that is added to water,
creating a mixture with a lower
freezing point and a higher boiling
point.
This mixture is called coolant.
Today’s coolants also prevent
corrosion and protect the inside of
the cooling system from rust.
Slide 25
As a car owner, you’ll be glad to know that the cooling system
requires very little maintenance. However, it cannot be neglected,
either! Here is a list of things you should do; each of them will be
discussed in a subsequent slide:
Check your coolant level regularly
Have your coolant changed at the correct interval
(specified in your owner’s manual)
Watch the temperature gauge or warning light on your
dash
Occasionally check your hoses and belts
Keep the radiator clean of bugs, leaves & dirt
Slide 26
Because it is so easy, there is no excuse to not check your coolant level
each time you open your hood to check your oil. Simply glance at the
coolant reservoir and make sure the level is somewhere between the
“min” and “max” marks. If it is low, add some coolant and check for
leaks. While it is normal for a very small amount of coolant to
evaporate over time, if you have to add coolant more than once a year,
you probably have a leak that needs to be addressed.
You should not have to open the pressure cap to check the
coolant level or add coolant unless there is none in the
reservoir. If you see none in the reservoir, it is time to open
the pressure cap (if it is not hot) and find out if there is any in
the radiator!
Coolant in the radiator
Slide 27
The answer to this question is simple: whenever your owner’s manual
says that you should. Coolant breaks down over time. It looses its ability
to protect from freezing, boiling, and corrosion. If coolant is not changed
on time, it can cause expensive damage to the engine, radiator, and other
components. No matter how much its costs to change your
coolant, it costs less than it would to replace your engine.
There are different types of coolants used in different cars. Because of
this, the service interval may range from “every 24,000 miles” to “every
150,000 miles.”
If the wrong coolant is ever added to your system, it may greatly reduce
the life expectancy of your coolant—so make sure you use the correct
fluid!
It is recommended that you take your car to a professional for cooling
system services and flushes. If you choose to do it yourself, remember
that roughly half of your coolant is in your radiator and half is in your
engine. Draining the radiator alone will only get half of it!
Slide 28
Depending on your car, your dash should have a
temperature gauge, a temperature warning
light, or both. If you have a gauge, the needle
should move to the middle of the gauge (about
210°F) as the car warms up, and never get any
higher than this.
“Danger Zone”—do
not continue to drive
If you have a warning light, it should come on
when you first turn your key on, then shut off
once you start your car. If it ever comes back
on while you are driving, the engine is too hot.
“Danger Zone”—do
not continue to drive
Temperature
Warning light
Temperature gauge
Slide 29
Belts
It is a good idea to periodically inspect
your belts and hoses. The belts keep
your water pump and other accessories
turning. If it breaks, the pump will not
circulate the coolant and the engine will
overheat.
Check your belts at each oil change,
looking for cracking and chunks that are
breaking off. Belts typically need to be
changed about every 60,000 miles
Cracking
Chunking
Hoses
Hoses transport the coolant from the
engine to the radiator and back. At the
same time you are checking your belts,
check your hoses for bulging, softness,
leaks, or other indications of
deterioration. Have them replaced at the
first sign of trouble.
Bulging (feels soft)
Leaking
Slide 30
Another way you can keep your cooling
system operating at its best is to
periodically check the radiator to make
sure it isn’t plugged with bugs, dirt,
leaves, or other debris.
A bug or two is not a problem, but if
buildup begins to block airflow through
the radiator, the coolant will not be
able to cool off enough and the engine
may overheat.
When cleaning the radiator, use water,
compressed air, or a very soft brush
(most auto parts stores sell an
inexpensive tool you can use). Using a
metal object to clean the radiator may
result in punctures and leaks.
Slide 31
In the past, all cars used the same
antifreeze/coolant. Not today! As mentioned
earlier, there are many different types of
coolants and they are not all the same. Even
coolants that are the same color are not
necessarily interchangeable.
The simplest way to determine which type of
coolant to use in your car is . . . you guessed
it . . . look in your owner’s manual.
Typically, coolant should be checked and added at the reservoir.
Unless you buy it pre-mixed, coolant needs to
be mixed with water before it is added to the
system. Neither coolant nor water alone has a
sufficient freezing or boiling point. However, a
proper mixture of both fluids does.
Remember this! For most climates, the recommended ratio of coolant to water is
1:1. This means that the coolant you use should be composed of 50% water and 50%
antifreeze, which provides freeze protection down to -35°F.
Slide 32
In this lesson we have learned about the indispensible roles of the
lubrication and cooling systems in your automobile. Without them,
the engine could not operate for very long.
Both of these systems require some periodic maintenance. Whether
you choose to do this maintenance yourself or have someone else do
it, becoming an educated owner is the first step to extending the life
of your engine and car.
Remember: keeping your oil and your coolant full and changed on
schedule is the most important thing you can learn from this lesson!