Over two years ago I had a head gasket job done on my 2010 Forester because of a leak. The heads and the valves where sent out. I even had timing belt and water pump done even though the car only had 72,000 on it. The mechanic who did the job is a Subaru master mechanic who decided to close shop after a better less stressful job offer. I now take my Subi to a local dealership and they've treated me good but I'm a little concerned about a recent diagnosis. My check engine light came on twice within one month. The error code pointed to a miss in cylinder 4. After the first error they replaced plugs, cables, and ignition coil. After the second appointment the said I would need a valve job! There were no compression or leak down tests performed and I was told that's the only other cause they can think of. Friends tell me to get compression and leak down performed first. What else could it be? And was diagnosis a little premature? FYI I now have 92,000.