The "big plug" is the port for the oil pressure bypass valve.  The
coolant is coming from somewhere else.  It could be from the water pump,
or from a head seal leak.  DMc

On Wed, Dec 30, 2009 at 6:07 PM, Aaron wrote:

> Hello all.
> I just noticed a coolant leak out of what appears to be a drain plug
> in the engine on the driver's side of my '87 westy. It's flat, about
> 1" across with a slot in it and sits just to the left and behind the
> oil drain plug. Anyway, I'm not sure if it's plugging the cooling
> system, but it appears that coolant is leaking out of there.  I
> suppose it could be the water pump as well, but it didn't appear to be
> dripping down from above. I'm planning on doing some driving this
> weekend and wanted to hear opinions on:
>
> Is the big plug likely where it's leaking from?
> Will this leak get worse?
> What's the best way to fix it?
>
> Thanks!
> Aaron '87 Westfalia