the service guys said they would like to open up the engine and perhaps loosen/adjust the tappets. is this worth doing?
2 days later - hey everyone thanks for your replies. some of you have said, there is no adjustment, and some have said, do it. My service tech is a Subaru specialist, and has quoted me $700.00(AUD) to loosen the tappets/lifters.But if some of you say that they are non adjustable, am l being played? Where is the proof that these are non adjustable so l can ask them more questions? Thanks again!

yes as it can cause damage if too loose or too tight , the tappet head can wear down or the top of the rocker valve can wear excessively , worst scenario is if the tappet head is now pitted on the underside or the valve head is pitted , get it set then if not cured you may have a serious problem of replacement .

Yes it is. It will give you more MPG if they are set correctly and you will lose the noise. Plus it dose not do the engine any good if the settings are in correct.

yes it can damage your engine and its worth doing

there is no adjustment on those tappets ( lifters ) there is a product called risolone ( comes in a yellow plastic bottle ) add one quart to ur oil as well as one quart of lucas oil stabilizer, remember to count the 2 quarts of additives so u dont overfill the oil l use the oil stabilizer every oil change my ford van with a 351 w has 220,000 miles on it, & runs like it thinks its part nascar, lol & just for ur general info, check out another product called sea foam ,you add it to ur gas, it will make u think u have a new engine

You've got solid lifters in your 2.5, and they are non adjustable. More likely the noise you hear is piston slap, which was bad enough to get some of those engines recalled. l would have someone familiar with Subaru is take a look.

your tech wont lie to you-id be his ass if he did-if u like you car-take care of it..do your service intervals and follow mechs advice- not a bunch of s on the internet