Hi
My Daishitspoo has a knocking noise coming from the head when cold, for a couple of minutes until she warms up. It definitely isn't a big end as far as I'm aware (what are the symptoms of a run bigend? other than the bang bang from the block!), it is definitely from the head, and goes completely away when the car is warm, with decent oil pressure.
Its' 16 valve with sohc/rocker setup. I've had a look at the rockers, they look good, all still have mint side thrust springs and minimal play.
My guess is either a sticky or bent valve? I would've though if it was bent, it wouldn't go away with oil pressure/temp. Tapping the cam cover with a sparkplug gives an almost identical noise. Dropped valve seal? What would that do? The car runs perfectly otherwise.
Any ideas?