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The Cooling System

The cooling system regulates the engine's temperature, removes excess heat, and provides heat to the passenger compartment. The water pump circulates coolant at high speeds. The cooling fan provides air flow when stopped or at low speeds. A belt-driven or electric fan is controlled by temperature. A flex blade fan reduces noise at high speeds. Sensors monitor temperature and controls electric or viscous fan speed. The radiator transfers heat from coolant to air. A thermostat regulates coolant temperature, and coolant provides freeze and corrosion protection. The heater core transfers heat from coolant to the cabin.

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264 views20 pages

The Cooling System

The cooling system regulates the engine's temperature, removes excess heat, and provides heat to the passenger compartment. The water pump circulates coolant at high speeds. The cooling fan provides air flow when stopped or at low speeds. A belt-driven or electric fan is controlled by temperature. A flex blade fan reduces noise at high speeds. Sensors monitor temperature and controls electric or viscous fan speed. The radiator transfers heat from coolant to air. A thermostat regulates coolant temperature, and coolant provides freeze and corrosion protection. The heater core transfers heat from coolant to the cabin.

Uploaded by

AMARNATHNAIDU77
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
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THE COOLING SYSTEM

Purpose
• To regulate the engines internal
temperature
• To remove excess heat from the engine
• To provide heat to the passenger
compartment
The Water Pump
• Centrifugal-type,
rotates faster than
crank, up to
10,000 gal. per
hour
• Pulley driven, belt,
chain drive or
direct drive
The Cooling Fan
• Provides air flow
with vehicle stopped
• Provides increased
air flow at low RPM
or vehicle speeds
• Belt driven or
Electric
Belt Driven Cooling Fan Clutch
• Limits actual fan speed
no more than 2000 rpm
• Engaged at low speeds
• Disengaged at high
speeds
• Thermostatic (temp.
sensitive)
Flex Blade Fan
• Fan blades
flatten out at
high
speeds,
reducing
noise,
increasing
horse power
Electric Cooling Fan

• Electric – 12v DC motor


driven fan
• Controlled in several ways
– Engine coolant temp (ECT)
switch
– A/C select switch
– PCM controlled based on
various inputs
• Fan turns on/off at specific
temps.
Electro-Viscous Fan Clutch
• PCM Controlled fan
speed
• Sensors monitored to
control speed:
– ECT, A/C request,
VSS, IAT, Trans Fluid
Temp, AAT
• Solenoid controls fluid
flow, regulating fan
speed
• Internal hall effect sensor
monitors fan speed
The Radiator
• Transfers heat from coolant to the
atmosphere
• Two types – Vertical & cross flow
• Aluminum, brass, copper core; brass,
copper or plastic tanks
• Air movement through radiator created
by a mechanical fan or by vehicle
movement (ram air) dissipates heat
How a Radiator Works
Radiator Pressure Cap
• Regulates pressure in the cooling
system
• Rated in psi – always replace with same
rating
• Pressure valve – allows liquid or vapor
to escape
• Vacuum valve – as system cools,
coolant can reenter the system
The Thermostat

• Regulates engine coolant temperature


• Rated in degrees – 195 degrees most
common
• Solid Expansion design – wax pellet
expands as temp increases, valve
begins opening at rating & is completely
open within 20 degrees
Coolant
• Provides freeze & boil over protection,
corrosion prevention & good heat
transfer
• Ethylene Glycol based – recommended
50/50 mixture with water, poisonous
• Dex-Cool – used by GM, 5 year
150,000 mile protection, doesn’t contain
silicate & phosphate additives
The Heater Core
• Small size radiator located in the dash,
coolant circulates through it. A blower
motor passes fresh air over it, heat
transfers to the cooler air and into the
cabin
• Many vans & SUV have rear heating
units
OLD NEW
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SUBMITTED BY:-

ASHU RANJAN
ROLL NO

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