Ticking sound coming from engine
first check your engine oil level. is this a new ticking sound or has it always been there? Subaru boxer engines are known for making a ticking noise and is said to be normal. if it is a new sound, you should have it checked out by a reliable mechanic. it is hard to tell without hearing it what it could be.
Is the ticking sound worse, louder, or better, softer in certain driving conditions? For example is it worse at idle than when driving down the road at 35 mph? During accelerations? In neutral vs in gear? Coasting in gear? Good advice above as first step, make sure the engine oil level is correct, and the oil appears to be in good condition (not black in other words) .