98 grand prix not holding any antifreeze no leaks but smoking coming from under valv e cover. I recently got a lower manifold gasket repair and ever since then the car idle is off and shakes.
OK, so you had the lower manifold gasket replaced, Since your loosing coolant and no leaks, I would say the coolant is leaking past this gasket. Also the idle will be affected by this condition since you see smoke. Take the car back to the shop you had the repair done, because it wasn't repaired correctly. Have them make it right
Looking for a Used Grand Prix in your area?
CarGurus has 2,863 nationwide Grand Prix listings starting at $1,600.
Search Pontiac Grand Prix Questions
Pontiac Grand Prix Experts