Here at VW Specialties we recommend flushing your engines cooling system every 2 years. The reason for this is that as coolant/antifreeze gets old it starts to break down chemically. As it breaks down it does not dissipate heat as well and it begins to cause corrosion in the cooling system. This corrosion can start to circulate through the cooling system and cause blockages. Also this corrosion causes excess wear on moving parts leading to failure. One common cause of water pump failure is poor coolant quality, since the pump is lubricated by the coolant. Almost all VW’s and Audi’s have a pink colored coolant. If you check your’s and it looks brown/rusty or like chocolate milk, it’s definitely time for a flush. If it looks good but hasn’t been changed in 3 or 4 years it’s probably time for a flush as well.