Questions and answers to the Maintenance and car control

(!) What does the coolant consist of? Coolant is a mixture of destilled water and antifreezing fluid in
order to resist temperatures up to –20 degrees.C. In emergency cases tap water can be used instead.
(!) Why does coolant need to be changed? Coolant consists of inhibitors of corrosion – they prevent the
engine from inside corrosion. This property, however, decreases with time.
10. Describe the function of the exhaust fume catalyst and its location and how to
influence its life span.
The catalyst is a device to lower the content of harmful substances in exhaust fumes of combustion
engines. It has a great environmental significance. It is part of the front component of the exhaust pipe –
near the engine. The life span is mainly decreased by:
bad driving technique (pushing the car to start, driving pointlessly at high revolutions etc.)
bad fuel (engines with a catalyst use unleaded gasoline (petrol)).
Fig.: The bottom
of Skoda Octavia
cars – a catalyst
(marked by the red
circle) in a
protective housing.