96 Legacy Outback lifter tap?

[rcote20]

My wife describes the sound that our subaru makes when you give it even the slightest amount of gas, as "the lawnmower noise" and honestly, that is a good comparison to what it sounds like. You hear it only when going down the road with the WINDOWS OPEN. It is a 2.5L DOHC with new headgaskets, timing belt and all components, blah blah blah, the whole nine yards, just had a fresh oil change and added some STP oil treatment (the problem, prehaps?) I am not too too worried about the sound, it's just annoying, especially after dumping a months worth of salary into our subie. It really is a great car, would just love to have this minor issue resolved. Any tips on how to get rid of that lifter tick or whatever it may be when giving it gas, would be GREATLY APPRECIATED! Thanks!

[lockmedic]

They're solid lifter (bucket and shim) so adjusting amounts to checking the lash on the current shim(s), removing it, and doing a bit of math to figure out the shim size you need to get it into spec.

If it is lifter noise, the STP won't have any effect on it unless they're bone dry, in which case you'd be about 30 seconds away from cam bearing failure. Not the case, just illustrating.

Were the valves ground when the headgaskets were done?

[rcote20]

I am not sure if the valves were ground when the headgaskets were done, i know that the manifold and exhaust valves were (if that sounds correct)

[cartwheels4amile]

I was fairly certain the 96 had hydraulic lifters... solid lifters were introduced in 97 with the revised EJ25D that ran on 87 octane. The 96 EJ25D ran on premium, made less power than the 97, and was only available with the automatic.

Going off this, it could simply be a sticky lifter. Correct me if I'm wrong here.

[canubaru]

I was fairly certain the 96 had hydraulic lifters... solid lifters were introduced in 97 with the revised EJ25D that ran on 87 octane. The 96 EJ25D ran on premium, made less power than the 97, and was only available with the automatic.

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i thought this as well, along with the set up being different than the 96 ej22 HLAs. not sure how, if it is really different.

do you think checking the valve clearance would be informative?

[rcote20]

Basically, I am wondering what my next step might be. You don't seem to hear it at idle, and not much if at all when reving it up in park, only when going down the road. Perhaps it's something else? Exhaust related? I am not quite sure. It just sounds similar to a "lawnmower" according to my wife. LOL!

[Glennda5id]

What does it sound like to you?

[rcote20]

Well, honestly, it kinda does sound like a lawn mower.

[ron917]

Maybe an exhaust leak?

[grossgary]

remember we can't see, drive, hear, touch, or otherwise diagnose *at all*, so while we have more collective experience than any Subaru dealer in the world.....we're really limited in what we can do on a forum as well.

if it was exhaust i would expect it should be noticeable if you were standing outside the vehicle and someone revved the motor while in neutral/park. try that first.

when it's revved up in neutral - park what does it do? any sounds then?

are you positive it never made this sound before the headgasket repair?

sounds like you have driven it some miles, sometimes the HLA's, if yours is so equipped, take some time to prime and quiet down after a head job. have you changed the oil since the HG job?

after that we'll need to know more about this noise - it could be the timing belt tensioner flopping around (a tap, tap, tap kind of noise) - this usually happens under load - which would be while driving as you're experiencing.