Idid change all gaskets, rings and anything you could think of including the cap. I had to take it into a mechanic and it was some pan that was under some pipe that was hard to reach..
I hope you have better luck with yours then I did..

SO RIGHT NOW I AM A PROUD OWNER OF A
2014 CHEVY MALIBU
I had to get rid of my 2014 CHEVY CRUZE 2 weeks after I got that car it ended up in the shop for a month it had a short in the wiring and burnt out my fuse box, fan and more.. For the 10 months I had it my car was in the shop more then I drove it..

But I am a die hard Chevy fan that I trusted them enough to get another Chevy..