top end problem?

i got a slight ticking coming from my head or close to there i just came back from a trip to a city about 4 hours away and i drove 4 hours straight there and i noticed the ticking parked the car for 2 days and still ticking after turning it on drove it home and it got a bit worse , .. any ideas on what it might be ? friend told me it could be valve clearance or dirty fuel injectors .
anythoughts on this matter would help thanks
anythoughts on this matter would help thanks