possible valve issue or ?

I have a 06 Legacy 2.5 with 149k miles. It was running fine until 2 weeks ago when I noticed a drop in power and decrease in gas mileage. It's sluggish at start up and then seems to feel like it's holding back on the hiway. There is a slight vibrating noise coming from the bottom of the engine when fully revved. Possible heat shield? My Subie tech thinks it may be the lower block has issues, possible valve problem. He's going to do a compression test and further check before ordering a rebuilt block. He knows someone who sells rebuilt blocks and can get one for $1200. From what I gather this is not unusual for Subies with 150k miles.Has anyone experienced these symptoms and had same result? Could this be something less serious from what I have described?Thanks,

Steve

Well get the compression test first but if you have a bad crank bearing that wont be able to tell you. This vibration does it feel solid like it is directly connected to the frame or more like that rattle?

 

How has the oil been kept up? Any knocking?

And any metal in the oil? Can cut open the filter to check

Thanks for the replies. No the knocking is more of a rattling vibration when you rev it in neutral and seems like a slight misfire when on the road. When I'm doing 60 I feel like I have to give the gas more throttle than normal to get up to 70. Possible plugs/wires?The vibration sounds like it comes ferom the bottom of the engine. That's why I thought maybe heat shield. I've had a couple replaced but they could be loose.The tech will have the car up on the lift Monday and check closer. Also, the last time the oil was changed there was no metal found. But we're going to check for metal in the engine again Monday. I've talked to other Subie owners who have had engine problems and this doesn't seem as severe as other problems that required an engine overhaul. But at the same time, I want to make sure if this is the start of something that could get worse that I take care of it now.

That rattling could be pinging and might explain the misfires. Might want to try some premium gas. My old explorer sounded like it had an exhaust rattle when it was pinging due to bad O2 and cam position sensors.

I took my Subie techs advice and replaced the shortblock after finding metal flakes in the oil. Found a rebuilt for 1300 delivered and parts and labor were another 700 including new tensioner for timing belt. Runs like new again, I'm looking for another 150k now with any luck