on a '94 9k cse lpt auto, the (12mm)4 no nuts holding the turbo under the exh manifold refuse to budge despite overnight soak in wd40? Can't get ring spanner around them....just open end! Any suggestions on how to open them?
Heating is the safest way. I did not have any available so I took my ring spanner and ground it down some and was then able to use it. A alternate to oxy/acetylene is MAPP gas which can be bought just like propane.
You could try a dedicated dismantling lubricant like "Plus-Gas". It's quite a bit more effective than WD-40 because that's exactly what it is designed for. Soak them for a while, then try *tightening* the nuts a bit to crack any corrosion, then loosening (that's what it says to do on the can).
If that doesn't work, then you're stuck with applying heat.
Not to make you jealous, but some of the nuts on my Aero were finger-tight...