The role of turbocharger

A turbo's basic purpose is to boost power, so when an otherwise healthy engine suddenlybecomes anemic, it often (but not always) means turbo trouble. 

Some of the symptoms thatmay indicate a sick turbo include a loss of power, loss of boost pressure, turbo noise, increasedoil consumption and oil fouled spark plugs, or excessive exhaust smoking on diesel engines &high fuel consumption.