lubrication and cooling system

8/6/2019 Lubrication and Cooling System

1/22

Lubrication and Cooling

System in an Engine


2/22

Upon completion of this lesson, the

students will be able to:

Upon completion of this lesson, the students willbe able to:

1) Identify where the cooling occurs in anengine

2) Identify where lubrication in an engineoccurs

3) List the parts in an engine where coolingand lubrication occurs

4) Know the importance of keeping anengine lubricated


3/22

There are a few safetyprecautions that

need to be followed when checking thelubrication and cooling systems in an engine

1. The engine should be cold before you start.

2. The cap on the top of almost every car or truckradiator (or on the separate coolant reservoir) isdesigned for safety first letting any built- uppressure escape slowly before the cap is

completely removed.3. Dont touch the oil because it maybe hot.

4. Wear gloves or use a rag.

5. Wear safety glasses.

Can anyone give me another?


4/22


5/22

Does anyone know the importance of

lubrication and cooling systems in an

engine?

The lubrication and cooling system of an

internal- combustion engine is veryimportant. If the lubricating system should

fail, not only will the engine stop, but many

of the parts are likely to be damagebeyond repair. Coolant protects your

engine from freezing or overheating.


6/22

What lubrication system does for an

engine.

1. The job of the lubrication system is to distribute oil to the movingparts to reduce friction between surfaces which rub against eachother.

2. An oil pump is located on the bottom of the engine.

3. The pump is driven by a worm gear off the main exhaust valve camshaft.

4. The oil is pumped to the top of the engine inside a feed line.

5. Small holes in the feed line allow the oil to drip inside the crankcase.

6. The oil drips onto the pistons as they move in the cylinders,lubricating the surface between the piston and cylinder.

7. The oil then runs down inside the crankcase to the main bearingsholding the crankshaft.

8. Oil is picked up and splashed onto the bearings to lubricate thesesurfaces.

9. Along the outside of the bottom of the crankcase is a collection tubewhich gathers up the used oil and returns it to the oil pump to becirculated again.


7/22


8/22

Proper lubrication of an engine is a

complex process.

Motor oil must perform many functions under many different operatingconditions. The primary functions of oil are listed below:

1. Provide a barrier between moving parts to reduce friction, heat buildup, andwear.

2. Disperse heat. Friction from moving parts and combustion of fuel produceheat that must be carried away.

3. Absorb and suspend dirt and other particles. Dirt and carbon particles needto be carried by the oil to the oil filter where they can be trapped.

4. Neutralize acids that can build up and destroy polished metal surfaces.5. Coat all engine parts. Oil should have the ability to leave a protective coating

on all parts when the engine is turned off to prevent rust and corrosion.

6. Resist sludge and varnish buildup. Oil must be able to endure extreme heatwithout changing in physical properties or breaking down.

7. Stay fluid in cold weather; yet remain thick enough to offer engine


9/22

What the cooling system does for an

engine.

1. Although gasoline engines haveimproved a lot, they are still notvery efficient at turning chemicalenergy into mechanical power.

2. Most of the energy in the gasoline(perhaps 70%) is converted into

heat, and it is the job of thecooling system to take care of thatheat. In fact, the cooling systemon a car driving down the freewaydissipates enough heat to heattwo average-sized houses!

3. The primary job of the cooling

system is to keep the engine fromoverheating by transferring thisheat to the air, but the coolingsystem also has several otherimportant jobs.

4. The engine in your car runs best ata fairly high temperature.

5. When the engine is cold,components wear out faster, andthe engine is less efficient andemits more pollution.

6. So another important job of thecooling system is to allow theengine to heat up as quickly aspossible, and then to keep theengine at a constant temperature.


10/22


11/22

Cooling systems consist of three main

parts:

1. Pumping

Your cooling system's

pumping function is

handled by its water

pump, which keeps the

coolant mixture moving.

The main water pump is

gear- or belt-driven but, in

many cars, a secondary

electric water pump is

used for improved flow

and cooling.


12/22


parts:

2. Piping

Your cooling system's pipingconsists of all hoses, any controlvalves, the heater core, the

radiator and the expansion tank.Because of the materials usedand the constant contact withcoolant, all parts in this systemdeteriorate more from time thanuse.

Maintenance of cooling system

piping consists of scheduledcoolant replacement, replacementof all hoses on a regular basis andreplacement of any plugged orleaking parts.

All hoses should be checked atleast twice a year for abrasions,cracks, flexibility and evidence ofleakage. Whenever the coolant isdrained for replacement or duringengine repairs, any suspect hoses

should be replaced. All hosesshould be replaced at least everyfew years.

Radiators, expansion tanks,heater cores and control valvesare normally only replaced due toleakage or plugging. The conditionof these parts should be assessedby a professional since properfunctioning is critical to many othersystems within your car.


13/22


parts:

3. Temperature Control

Your cooling system's temperature controls include all coolant temperaturesensors, thermostat, radiator or expansion tank cap, cooling fan(s) and fan

clutch (if equipped). These cooling system parts function primarilyindependent of the engine but control the engine either through cooling orby sending control signals to your car's electronic systems.

The thermostat is a spring-loaded valve that opens and closes based on thetemperature of the coolant flowing through it. A high temperature readingfollowed by a drop to normal temperature (or a continuously lowtemperature) is a common first sign of a sticking thermostat. However,

many other conditions may cause these symptoms, so you need to knowhow to eliminate each possibility.

The radiator or expansion tank cap is also a spring-loaded valve reacting tosystem pressure. It serves to maintain proper system coolant level atpredetermined pressures. It must always be replaced with an exactreplacement cap with the same pressure setting. Never use other capsexcept for short-term emergencies!


14/22


15/22

Liquid Cooled System

In a liquid cooled system, heat is carried awayby the use of a heat absorbing coolant that

circulates through the engine, especially aroundthe combustion chamber in the cylinder headarea of the engine block. The coolant is pumpedthrough the engine, then after absorbing the

heat of combustion is circulated to the radiatorwhere the heat is transferred to the atmosphere.The cooled liquid is then transferred back intothe engine to repeat the process.


16/22


17/22

Maintenance of your cooling system

Maintenance of your cooling system sensors is

virtually impossible since there's nothing really to

"maintain". Keeping them clean both internally(coolant replacement) and externally (engine

cleaning) is the best way to ensure trouble-free

driving. Checking and replacing all parts at the

factory-recommended time or mileage limitshelps as well.

Is there any questions?


18/22

Lubrication and Cooling System

The lubrication system ofan internal-combustionengine is very important.If the lubricating system

should fail, not only willthe engine stop, but manyof the parts are likely tobe damaged beyondrepair.

The only purpose of theengine's cooling systemis to remove excess heatfrom the engine, to keep

the engine operatingtemperature at its mostefficient level, and to getthe engine up to thecorrect temperature assoon as possible afterstarting. A cooling systemis also required to preventthe internal engine partsfrom melting from theheat of the burning fuel.


19/22

Engine Failures

Does anyone know

the how many engine

failures are attributed

to cooling systemfailure?

-Over 50% of engine

failures can be

attributed to cooling

system failure.


20/22

Thing needed to repair a cooling system

Can anyone list some of the things needed to repair a coolingsystem?

- Coolant- Water Pump

- Water Pump Drive Belt (timing, V-, or flat)- Hoses (upper & lower radiator, bypass, heater, manifoldcoolant, etc.)

- Radiator- Expansion Tank- Heater Core- Control Valves- Temperature Sensors- Radiator Cap and/or Expansion Tank Cap- Fan Clutch

Can anyone tell me how important a lubrication system is in anengine?


21/22

1) What does an Oil Pump do?

2) What does an Oil Pan do?

3) What does an Engine Oil Cooler do?

4) What does an Oil Filter do?

5) What does a Water Pump do?

6) What does a fan do?

7) What does a Radiator do?

8) What does the Transmission Oil Filter do? 9) What does the Transmission Oil Cooler do?

10) What does the Liquid Cooling system do?


22/22

1) http://www.autohausaz.com/html/cooling_systems.html

2) http://auto.howstuffworks.com/cooling-system.htm3) http://science.howstuffworks.com/engine12.htm

4)http://www.tpub.com/content/fc/14104/css/14104_115.htm

5) http://www.tpub.com/content/constructionforklifts/TM-10-

3930-660-10/css/TM-10-3930-660-10_22.htm

lubrication and cooling system

Documents