So I had a V/C leak and decided to change out the gaskets. I had a mechanic replace them about 2 years ago, and had to take it back within a year because they started leaking again. Needless to say, they were leaking again so I decided to replace them myself. Got it done, and they aren't leaking anymore, but check out the gasket from the leaky side. What could cause this to happen?

 

Maybe the cover wasn't seated in the gasket correctly and it got pinched and eventually ripped? Over-torqued bolts sounds logical, I don't remember them requiring a whole lot of torque. Those are complete guesses of course.

 

The valve covers were to loose and they rubbed on the gasket and ripped it.
Buy a 8mm 12 point 1/4" socket and everytime you change the oil snug up those bolts and it wont leak for 10 miles.
Seriously, do this and they will never leak.

 

The ripped part is actually the top, not the bottom. Can't get to those bolts without removing the intake. I really don't know how they got like this...had to be during the original install.

 

Gasket gnomes have been known to slash gaskets, but never caught in action. That's one possibiliby. More likely, they were mis-installed last time causing it to bend-over and break. Or, they may have been defective from the mfgr. Anyway, a good mechanic would have gotten them on straight or should have caught that. Another good reason just to do it yourself...

 

Due to the metal inserts in the hole where the bolts go, it's hard to over torque the gasket. From your pic it's hard to tell if the metal inserts are there. Maybe they fell out and the prior mechanic didn't notice it was gone. Then he proceeded to over torque the gasket causing it to tear prematurely.