[Vwdiesel] Oil leaking into water

[Sherwin Goff]

  Instead of the oil filter spinning onto the bracket attached to the engine block, as is normally done, my engine has an oil cooler attached first and then the oil filter spins onto the oil cooler.
   
  On my VW diesel engine there is an oil cooler. This oil cooling unit has water hoses connected to it so that the engine’s cooling system circulates water through the oil cooler. It’s like an added unit that the oil filter spins onto. The cooler is between the oil filter and the oil filter’s normal receiver on the engine’s block. 
    
  I’m getting oil in the water. Now, here is my questions
   
  1. Do these water coolers have a history of leaking oil into the water cooling system of the engine? 
  2. Is replacement the only repair process for stopping this type of oil cooler leaking oil into the water? 
  3. How would one test this to be sure that the leak is coming from the oil cooler instead of from some other possible source? 
   
  SherwinGoff at yahoo.com.