I have an earlier AAH style V6 which has lost oil pressure. I belief that it is a failed relief valve nearest to the Oil Filter. If I am looking at the correct component, it's approx. 6mm Male thread under the control plate which feeds the filter and is threaded into the upper sump housing.
Does anyone know how to remove this unit? There is no obvious way to extract it without a pair of needle nosed Vicegrips.
Thanks for your time.....

I think you are looking at the right thing, but I have no idea how to remove it. Bentley offers no clues. :(

You mean item "C" below:
<img src="http://www.12v.org/engine/images/AAH-oil.gif">
I've never noticed that on my '94 AAH, I've even removed the upper pan and cover plate! Any chance of a digi-pic of the valve?

Anyone with an ETKA copy confirm the part number for this valve? thanks.