my first thought was locktite red.. but just plan before you use that stuff.. the red is perm and takes lots of heat to break the seal.. IF you use it be CAREFUL and use a very small amount.. and be warned that those bolts may NEVER come out again.. had an exhaust manifold bolt on a truck engine keep backing out.. gooped it up with red locktite.. never did back out again.. but when it came time to replace the manifolds.. that bolt ended up snapping off and had to be drilled out and hole retapped. i would first try new bolts and some lock washers (might not be pretty, but should work)
i now avoid locktite red after that experiance.