Re: Will it BLOW
I'd fix it - as Mark42 says, you could start getting cooling water leaking into the cylinders, which will kill your motor.<br /><br />Did you have the head off? Reason I ask is that bolt stub may be very easy to remove. The block is aluminum & the bolt is steel, so when you heat the area up, the parts will expand differently and work their way loose. If you remove the head, most of the time you'll have a stub of bolt left that you can grab with vice grips. HEAT THE THING FIRST with a propane torch - about 60 seconds worth, then try the vice grips. Take your time, you don't want to mess up the stub or your job just got harder. Work it back and forth, taking it easy & spraying on PBBlaster. Don't force it - if it doesn't move use more heat & time. It's the heat/cool cycles that does it.<br /><br />DEFINITELY use a new head gasket when you re-install. Torque it down to specs, then re-torque after the first run or two.