OK. just gone to change the oil in my 93 WRX. Warmed up the engine, undone the oil filter and bugger all oil has come out, the dipstick still says full !! dosnt make sense to me, what am i missing ? some sort of valve need to be undone ?

 

You need to remove the sump plug to get the oil out, although i you should have got some out from removing the filter. Do you mean none what so ever or just a trickle?
Anyway remove the sump plug

 

Yeah just ignore that, been a long day and i forgot to remove the sump plug !!! no idea why iv changed oil loads of times in the last 5 or so years !

Doh ! how stoopid do i feel !