My valve cover gasket is leaking a lot of oil, and I need to replace it, but none of my local auto parts stores have one in stock. I don't have a whole lot of free time to work on my car, so I can't wait for them to order it if I don't have to. Is silicone liquid gasket a suitable replacement?

 

No. It will leak more.

 

Depending on which engine you have you should also replace the cam plugs along with the timing chain gasket & seal.