rocker cover gasket life expectancy (throw some comments around)

i had sorta the same thing except i found my leak when it dripped on the headers and smoke pissed out. popping the bonnet and putting out the small fire was fun!! That set was a cork set and they'd torn on install, I now always glue them on first! that is the trick, i just go dodgy and put a few spots of superglue, its fast and works.

 

toyota, you'd expect 200,000km without issue.

commodore, if it makes it to 20,000km you're lucky.

 

New genuine holden rubber gaskets are said to be the best. They are also reusable. Cork/ paper ones with an aviation grade sealer are also good. Just you have to change them every time you take the rocker covers off. Just make sure all the allen headed bolts are done up properly. Also see if the head mating surface for the gasket hasn't been damaged by someone trying to get old gasket off

 

Using original parts should help, also make sure the bolts is all done up the same tightly. Do bolts up finger tite then work from the middle out like you do on a head gasket to nip them up tite. Silicon aviation grade sealant can be smeared on mating surfaces first for xtra insurance. I also lightly sand mating surfaces with very fine wet and dry to make sure the sealant gets a good grip and to take off the last traces of the old gasket/sealant.