The owner of this vehicle was complaining of an over heating engine. We diagnosed the issue as a fault in the VANOS system.
Read on to find out exactly what we did to rectify this issue, we have some pictures to show the before and after results too!
Vanos information (courtesy of Wikipedia):
VANOS is a variator system that varies the timing of the valves by moving the position of the camshafts in relation to the drive gear. The relative timing between inlet and exhaust valves is changed.
At lower engine speeds, the position of the camshaft is moved so the valves are opened later, as this improves idling quality and smooth power development. As the engine speed increases, the valves are opened earlier: this enhances torque, reduces fuel consumption and lowers emissions. At high engine speeds, the valves are opened later again, because this allows full power delivery.
We stripped down the cylinder head which is where Vanos is located and were able to then take apart the various components of the Vanos. We found a large build up of dirt inside the components that we were able to clear out.
We removed all of the Valves, Valve Springs, Valve Guides and Seals. These were re-machined and made better than standard.