please help me diagnose strange problems?

[97scoob]

so i just pulled my motor to do a clutch on my 97 outback 2.5, and i had to take one head off to get some studs machined out, and when i put everything together and put the motor back in, it runs, but it shakes really bad when running. i don't know if it is timing, or what to think. see if you guys can help me out on this one.

[decke48]

vaccum leak mostlikely. but its hard to say when your not there

[ivwarrior]

Could be a timing belt that's a tooth off, too.....

[97scoob]

it ended up being that one of the camshaft sprockets had been put on a little bit cocked to the side (stupid mistake made at 5 in the morning), and this made the timing belt skip a tooth on that one sprocket. put it all back together, runs for a few minutes, then all the symptoms of a blown head gasket. almost positive it is. not really sure yet, checking it out tomorrow morning. running on like 5 hours asleep over the past three days including thanksgiving, so i need to finally get some well needed sleep tonight.

[97scoob]

so its definatly a head gasket. ran a compression test, and on one side, compression was fine (120 PSI) and on the other, it was 80 PSI, which is obviously low. also, we let it run for a bit, and after about 5 minutes, it started pouring white smoke out the exhaust, and the oul was all foamy. so now i have to pull the motor back out and start all over again!!! :smt021 so annoying. so thats what i have to look forward to over the next three days.