03 Legacy valve tap

[Doug77]

2003 Legacy 2.5L w/slightly over 100,000 miles.
Had overheating issues. Took it to the garage and they shaved the head and just recently decked the block because it overheated 2 months after they re-surfaced the head. We got the car back from the shop and the overheating seems to be gone. We had to take it back to the garage after 1 week though because a loud valve tap and low power suddenly came on.
The mechanic adjusted the valves. He said a couple of them were out by 10 thousandth. He does not understand this because the valves should not need adjusting. He said nothing they did should cause a valve adjustment.
Anybody out there that can tell me what the mechanic or machinist might have done wrong? I'm a backyard mechanic, but this is over my head.

[RahX]

Well, Subaru uses a bucket under the cam to space out the distance from the lobe to the valve. They MIGHT have mixed up the buckets which shouldn't cause any damage but would cause the tapping. As far as the tapping goes, tap=ok knock=bad as long as you're sure it's the valvetrain. It's pretty rare if a Subaru needs anything more than a minor adjustment, usually don't worry about it unless you're in there already. Although they should be careful with shaving the head/block as it reduces the distance that the cam gear is from the crank which could cause timing issues. Subaru headgaskets leak like crazy even if they're properly torqued, Subaru has an additive that does wonders. You should make sure they put that in the cooling system. If not, go to a suby dealer and get a bottle, its a small blue bottle with a red or orange cap. Get as much in there as you can, you'll probably make a bit of a mess getting some of the coolant out to make room for the additive so make sure to wash it with a lot of water.

[Doug77]

Thanks for the tip on the addative!
I finally got the car back. The tapping is gone. They told me that the machinist loosened the rockers and usually adjusts them back when he is done. They normally do not have to adjust them because the machinist takes care of it. This time he apparently forgot? Does that make sense?
Would he even need to loosen the rockers to deck the block?
I have asked around and the machinist is the best guy in town. He actually has a jig that he made so that he can deck the blocks without having to tear the entire casing apart.
Well, head was shaved, block was decked, new radiator (old one only had 9GPM flow rate, should be 24), new thermostat, oh...we had the timing belt done at the same time. Thought it would be smart.

[RahX]

Shaving a fully assembled head is like trying to have a blind man cut off your underwear without damaging your junk not impossible but definitely scary lol

The engine is an overhead cam and does not have rockers. There are caps that hold the cam down, like 5 of them and he probably loosened them to get the valves to close. If you have any sort of valve trouble with either head or an oil leak from the valve cover area i'd take it back and complain since it could very possibly be caused by that. But, then again you may not have trouble.

[Doug77]

What would cause the oil leak? Not to sound stupid.

[RahX]

The front cap that holds the cam down seals around the cam seal, If it was loosened and they didn't apply sealer properly it could leak. Not saying it will, it's just a possibility.