[TCSGTO]

I had a similar condition once when using aftermarket spring retainers with the stock o-ring seals on the valve. The stock retainers are longer and the bottom and capture the o-ring, the aftermarket retainers caused oil to be sucked down the guide. It would puff blue smoke at idle and clear up when driving. Positive seals on all of the guides fixed the problem.

If the leak down or compression test come out normal, pull the intake and see if there is oil on the top of the valve heads. Sure sign the oil is coming from up top.