[oldsaab93]

T4 all now fixed and back in action.
Helpful local forum member read error codes - misfire on cylinder 4.
Bought 2x new coil packs, plus plug leads and spark plugs.
Car now runs better than ever, so assume that the one coil pack that had failed was already weak/compromised.
In daylight the mayo on dipstick was only minor, cold weather period? Nothing under the oil filler cap.
Thanks for pointers and advice.