Oil on engine & Intake manifold question

[Grandamsse2]

There is oil on the side of the engine under the
thermostat. Looks old but when i smear it its fresh
oil under old oil. Not sure whats going on. the Valve cover
gasket was replaced by the previous owner.

Also can any one post me a pic of the
intake manifold? upper and lower.
Im not sure where it is on a 96 ga 3.1

[Onca Negra]

sound like the valve cover gasket even if it was replaced it may not have been put on correctly and thus still leaks....or the valve cover maybe slightly warped and need a lil extra gasket sealent to make it seal up properly.....
when i bought my car used the owner said they did the gasket job and it still had problems so i went and got the rubber gasket for the car not the cheaper ones made out of cork or dense fiber paper and replaced it ...
just remember you have to wipe down the rubber gasket with rubbing alcohol before putting it on for it removes the slippery gunk they use to get the gaskets out of the molds when they make them .....
also i would recomend getting the spray tack/contact adhesive for gaskets that your parts dealer sells made by mr.gasket or felpro
it makes installation easy all you do is spray the gasket lighty after cleaning the gasket with alcohol and then spray the valve cover lightly wait a few moments/minutes....
then stick the gasket to the valve cover carefully lining up all the holes between the valve cover and gasket start from one side then slowly fit it into the valve cover aligning all the holes as you tack it into the valve cover ....
this way it doesnt stick down and then its hard to adjust the gasket into place...
after that aligning the gasket inbetween the head and valve cover it easy all you have to do is drop the valve cover on(since the gasket is stuck to it) and put in the bolts then tighten them to the proper spec but not too tight ....
then clean the motor if you want ....
i havent had a problem since when i did it this way .....
good luck ...wish you the best on your project