Have just bought a 93 import wrx. Unfortunately when I got there the guys was at work and drove the car to where I was (therefore already warm). Everything checked out no smoke noises etc under load or on acceleration. When I started it this morning white smoke ensued, then once I drove off nothing more. Its booked into scooby clinic on friday for a general once over. Am i right in thinkning its probably the stem seals as the car although has only done 84,000km is over ten years old and the seals probably are on the way out?

Or is it something more serious?

Regards