Australian 4WD Action – July 2019

I

t’s a question I get asked

all the time. “Do I need to

let my turbo cool down

after driving?” To answer

this we need to under-

stand the difference in cooling

an engine and cooling the turbo

on it.

Modern diesels are all

water-cooled. They have a fan

that varies in speed dragging air

through the radiator. Regardless

of road speed, the hotter things

get the more the fan helps to

keep the cooling system working.

Stop the engine and the cooling

system effectively stops being

cooled. If you measured the water

temperature with an external

gauge at this time, you might see

it continue to go up a little before

dropping as the engine naturally

cools. Remember the engine is

cooled by the cooling system. The

turbo on the other hand is not

cooled as such. It might be a

water-cooled type but this isn’t

cooling the hot exhaust housing.

The turbo is designed to be part

of the hot exhaust system and so

is very durable to heat. In

particular, the exhaust part of the

turbo is designed to get hot.

Since exhaust gases keep it hot,

it’s only logical that once you shut

the engine off the turbo

temperature can only cool

down, unlike the cooling system

on the engine.

So in summary, all engines

with a cooling system need a cool

down after long sustained full

load. This means everyone

towing or running fully loaded.

Once you shut the engine off, the

engine cooling system will

continue to get hotter before it

cools down. By nature of backing

the foot off a few kilometres

before you stop is the best cool

down you can give it as you are

still moving with lots of air going

through the engine bay.

‘So... do I need to cool down

my turbo?’ Not really, but you

should consider next time to cool

down your engine, especially if

you are stopping immediately

after heavy towing.

Safe Driving!

Andrew Leimroth

Berrima Diesel-

The Diesel Experts

WORDS BY ANDREW LEIMROTH, PHOTOGRAPHY BY 4WD ACTION

CONTACT

BERRIMA DIESEL SERVICE

Old Hume Hwy, Berrima, (^) NSW (^2577)
( 02 ) (^4877 1256)
http://www.berrimadiesel.com.au
Do you need to let your turbo cool down before shutting the
vehicle off? Andrew from Berrima explains
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