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.BIGHANK

 

Nuts on plastic plenum cover getting stuck on studs is not that uncommon. There are no wires that attached to it. Once you get cover loose, use 10mm open end wrench or vise grips to keep studs from turning and remove nuts.