[Vwdiesel] Oil leaking into water

[James Hansen]

Sherwin Goff wrote:
>   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 is also normal, and how it is normally done.


  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? 

Anecdotal only.
As far as I can recall, I have heard of one.

>   2. Is replacement the only repair process for stopping this type of oil cooler leaking oil into the water? 

Absolutely. If it is indeed leaking, yes.

>   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? 
> 
Pressure test.  Pressure the coolant lines and see if air leaks from the 
oil passages. 40 or so lbs regulated air supply should do the trick.

Disconnect the coolant lines, and bypass the cooler.  Drive the car, see 
if oil continues to leave the cooler after a few days. Don't do any big 
long uphill pulls, as the cooler is there for a reason...

USUALLY, it is the copper o-ring around the oil passage on the head 
gasket that has failed.
Oil hits 100ish psi on startup, and leaks to the coolant then. New head 
gaskets have addressed this.
-James