Help with thermostat problems (Opel Vectra B)

Removal the thermostat

A jammed thermostat in a model with an eight-valve 1.6-liter engine cannot be removed on the road without a well-stocked toolbox. The thermostat is located on the front side of the engine behind the timing belt cover. In models with other engines, the thermostat is located on the right next to the exhaust manifold in the cylinder head. Dismantling is not a problem.

Drain the coolant into a container.



8-valve engine with a working volume of 1.6 l: loosen the tension of the alternator poly V-belt and remove it, see the chapter on the alternator.

Disconnect the coolant hose from the thermostat housing.

Remove the timing belt, see the engine chapter.

Remove the rear timing belt cover.

Loosen the thermostat housing mounting bolts and remove the housing.

Remove the thermostat from the engine block.

When installing, insert a new sealing ring into the engine block. Tighten the bolts to 10 Nm.

16V Engine: Loosen the coolant hose at the outlet pipe and then remove.

Unscrew the drain pipe from the cylinder head and remove it together with the thermostat.

Press the thermostat spring plate firmly, turn the thermostat and remove it from the outlet pipe.

The defective thermostat is replaced together with the coolant outlet pipe.

When installing, use a new sealing ring. Tighten the bolts in the 16V 1.6L engine to 8 Nm and in the 16V 1.8 and 2.0L engine to 15 Nm.

After installation, fill with coolant.

Checking the Thermostat

With the built-in thermometer you can control yourself whether the coolant flow regulator opens at the prescribed temperature:

Remove the thermostat.

Hang the thermostat in a container of water and heat the water.

Check to see if the valve disc lifts in the seat and opens fully.

The following values are set for Vectra engines:

Start of opening at 92°C, end of opening at 107°C.