Operation of the cooling system (Opel Vectra A)

The engine cooling system of Opel Vectra/Calibra cars has forced circulation of coolant and automatic regulation of its temperature. The coolant contains anti-corrosion additives and should be used both in winter and summer. Before the cold season, the density of the liquid should be checked. There is a safety valve in the expansion tank cap that maintains the pressure in the system within 1.0-1.3 bar. Increased pressure increases the boiling point of the coolant to 125°C. In order to prevent the occurrence of a vacuum in the system hoses during engine cooling, there is a check valve in the cap that opens air access to the cooling system when the pressure in it drops to 0.06-0.10 bar.

Coolant flows through the radiator from top to bottom, being cooled by the air flow blowing over it. The system pump draws the liquid from the bottom of the radiator and delivers it through a hose to the cylinder head and block.

The cylinder head is designed in such a way that the coolant is supplied through internal channels directly to the valves, cooling them. From here the liquid enters the cylinder block. After cooling the cylinders, the liquid enters the thermostat and, having passed through it, enters the upper part of the radiator through a hose. The cycle is repeated.

When the coolant temperature is below 92°C, the thermostat is closed. The liquid is sucked in by the pump through the bypass channel directly at the thermostat and fed into the cylinder head channels. This ensures uniform and rapid engine warm-up. When the liquid reaches a temperature of about 92°C, the thermostat begins to open, and at a temperature of 107°C it is already fully open, and the coolant passes through the radiator.

[Original source on the website: OPELBOOK.ru]