Better keep a close eye on the oil to have anti-freeze in it also.
This is deadly to the engine bearings. As to the cause could be anything.

            Eric                   86-VW4x4
            vw4x4@fyi.net          86-SS Syncro
            Pittsburgh, PA USA     1936-Chrysler
                                   92-Jetta GWC
            www.fyi.net/~vw4x4/vw4x4.htm

On Fri, 2 May 2003, Andy Yarnell wrote:

> I have heard several ideas about why I have coolant in my oil, and oil
> in the bottom of the expansion tank.
>
> Is my oil cooler to blame? Broken head stud? Bad cylinder sealing
> gaskets (green and black)?
>
> After looking the archives, I thought it probably was a bad oil cooler,
> but now I am not sure after talking to a fellow
> Vanagonite near me (Zoran in Golden, CO).
>
> I would like to hear from those folks who have had this problem, oil and
> coolant mixing, and what the problem was, and how
> you fixed it.
>
> Thanks, and have a great weekend!
>
> Andy
> Lakewood, CO
> 1987 Wolfsburg GL
> 1992 GTi
>