2001 Legacy 2.5 SOHC won't rev above 1000 rpm after new head gaskets

[nwalk7800]

I just bought this Legacy late last year only to discover that the head gaskets needed replacing. It ran ok before other than bubbles in the coolant tank and constant overheating.

I had the heads machined flat and used fel-pro head gaskets. After putting everything back together it's just not happy.

On startup it idles terrible like it has bad miss. I assume that's because of the cold fast idle because once it's warmed up it idles nice and smooth. However, if I rev it past about a 1000 rpm it starts sounding like it's got a big miss and it's really unhappy. There is no check engine light and no codes.

I replaced the plugs and wires, and tried pulling the plug wires one at a time to see if there's a problem on one cylinder. They all behave the same. I replaced the cam and crank sensors. I pulled the timing cover back off to verify the timing belt is on correct; 47 teeth to the passenger and 43.5 to the driver (despite what the service manual says). Compression on all cylinders is 150. I disconnected the exhaust before the cat to see if clogged cats were causing me trouble.

I'm hoping one of the Subaru experts here will have some ideas, because I'm all out.

Thanks for your time.

 

[Conkatonk]

So what was the cause? This is my experience now.

 

[nwalk7800]

I never could narrow down the cause and the problem only got worse. I ultimately just assumed I had burned up valves or something else wrong with the heads. I ended up replacing the engine with a used one off eBay. I wish I would've just gone that route in the first place; it would've saved me time, money, and headache.