I tried to unbolt the engine "beauty cover" on my newly acquired 1999 Deville. Right front nut came off BROKEN. Part of it is still in the hole on the cover. Left front came LOOSE but stayed in the cover. Rear 2 nuts turned a lot but refused to let go of the studs which hold the cover on top of the manifold,
When I tried to lift the front of the cover (remember these nuts came off of the mounting studs) saw and felt wires or something ATTACHED to the underside of the cover. I quit then and tried to rebolt the plastic nuts. One of them JUST GRABBED the stud while the other one went down and kinda cocked the cover so that it was almost squashing two of the plug wires.

WHAT IS THE TRICK HERE? My C5 Vette has 2 beauty covers but they simply SNAP OFF. One side requires bending it to release the metal fuel lines but nothing is attached to the underside of the covers.

Have looked in the GM Service Manuals and the Haynes Manual but can't find any reference to removing the covers to say replace spark plugs etc.

Please enlighten me.:banghead:BIGHANK

The studs are threaded at both ends if I remember correctly and are threaded into the manifold. Keep turning them and you should remove the entire stud. Then you can reinsert it tightly or put some thread lock on it to prevent it from coming loose in the future after you remove the nut. As for the one that broke, try putting two nuts on it and tighten one against the other. Then try removing the stud.

Same thing happened to me, I eventually ended up breaking 3 of the bolts, I just left it off, a little more engine noise, but I actually liked it better.

I had one stud totally come out like that on me once. My solution was a drop of locktite at the bottom (Into head) thread for the part that holds the manifold on, and I just hand tighten the nuts on top. Just grab a 13mm deep socket by hand and twist on it. You'll get more than enough torque to tighten it enough that you will not have to worry about it coming loose, especially with the rubber grommets in the cover where the nuts go.