On a 1989 740 90K miles...After cleaning up the grounds on the 2 rear valve cover bolts I tightened the nuts to about 14 pounds, and then snugged up the rest of the nuts to the same setting. The middle bolt on the driver's side gave very little resistance so like an idiot I kept trying to get the torque wrench to snap; instead the bolt snapped--the end of the bolt appears to have pressed into the cap of the nut and busted it there, ripping the bolt in two. It is broken off below the level of the cover.

Can I leave it alone and operate with one less bolt, or do I need to fix it? If so, how? Does it get re-tapped and a new bolt thread inserted, or tapped to screw a bolt into the head?

Will I see evidence of an increasing need to fix it? is cover warpage an issue? Etc.

Are there any types of nut fasteners that could reach down to catch on the bolt stub?

Is 14 pounds too much?

(I have not run the car since it happened so have no evidence of any oil leakage.)

Thank you for any advice...