Australian 4WD Action – August 2019

WHY STANDARD TEMP

GAUGES DON’T CUT IT

CAN I JUST RUN ANY

OLD COOLANT?

Standard temperature gauges are often only a graph with no

actual relation to temperature, and the actual range may only

be from around 80°c to 110°c (depending on the manufacturer).

While 80°c to 110°c is a normal operating range, you still don’t

know how quickly it is rising or exactly what temperature you

are running at.

With age these can start becoming less accurate, and can

hide small changes in temperature. If you are pushing the

limits of your cooling system, a quality temp gauge for oil and

water is a must, and a great early warning device.

Getting your coolant mix right plays a vital role in making your

4WD run cooler. While water is extremely efficient at

transferring heat, water on its own isn’t going to work. Why?

Because water freezes at 0°C and boils at 100°C, which is too

narrow a range for most engines, particularly in colder

climates where it could freeze and block up the engine’s water

jackets. Not to mention, water alone will quickly rust out vital

parts of your engine.

To get around these problems we mix ‘ethylene glycol’ with

water at just the right ratio to make ‘coolant’. Put simply, the

more glycol you add, the lower your freezing temp and higher

your boiling point. The down side is, though, ethylene glycol

isn’t as good at transferring heat as pure water, which is why

it’s important to get the ratio just right; the ratio depends on

the brand of coolant you use, so check the label).

With the engine cold and

coolant level full, pressure

test cooling system. Did it

hold pressure?

Rectify coolant leak -

Locate leaking hose or

gasket and replace, then

flush coolant and recheck

Radiator cap

fault -

Replace cap

and top up

coolant Fan belt fault -

Tension or

replace if

nessesary

Is fan belt in place,

tensioned

correctly and

turning smoothly?

Is the viscous

coupling

working

correctly?

Viscous

coupling fault -

Replace

fan fault -

Inspect fan is

fitted correctly

and is not

missing fins.

Replace as

required

fan shroud

missing or

broken -

Replace

Leave

engine to

cool, remove

thermostat

and check

operation. Is

thermostat

working

correctly?

Jammed

thermostat -

Replace

NO NO NO NO

NO

NO

NO

yes yes yes

yes yes

yes yes

Pressure test

radiator cap.

Did it hold

pressure?

Is the radiator

fan working

correctly?

Is the fan

shroud

complete and

in place?

At full operation

temp, carefully

feel both

radiator hoses.

Are they both hot

Blocked radiator

• Remove and
  service

NO

yes

OVER

HEAT

ING^

Honing in on an overheating problem is easier than you might

think. There are a few basic tell-tale signs to watch out for,

and some surprisingly easy remedies once you delve into it.

To help steer you in the right direction, we’ve put together

this simple step-by-step troubleshooting guide. For this

exercise, we’re going to assume basic servicing is already up

to scratch - things like engine oil, coolant mixture, brakes and

wheel bearings are all in good working order.

TRO

UBL

ESHO

OTIN

G^

MAD

E^ EA

SY!^

ES

SE

N

TI

A

L^

C

O

O

LI

N

G

S

YS

TE

M

M

O

D

S

T

E

C

H

T

A

L

K

Filling your (^) cooling
system with the right
coolant is crucial