I just noticed today that there is a rubber gasket sort of thing on the area where the radiator cap sits. It sits inside the recess and sits nicely in a lip. Which seems like it's meant to be there but it's not part of the radiator cap. Picture below. Is this rubber piece normal? Because my new radiator cap has its own rubber too

Can anyone else share pic of there radiator cap open?

Thanks

 

Did the gasket fall off the radiator cap? That is not supposed to be there.

 

Get something like a flathead and pry that out if you can, or pull it out. It's the gasket from the cap but good this happened and not the other where for me the cap broke itself in the hole and it was a joy to get that out. Go buy yourself a new rad cap from the dealer. Edit- sounds like you already got one.

here's my old thread, pics below it.
https://www.clublexus.com/forums/is-2nd-gen-2006-2013/937946-is350-broken-radiator-cap-w-pics.html

 

I get the feeling it could have been the gasket from the yellow burping funnel adaptor that I could have at some point accidently left inside. Picture of the gasket removed and showing how snugly it fits that yellow adaptor. I've removed it now. Pics of it removed and pics of my radiator cap below too. Does the radiator cap look normal? I'm surprised how the radiator cap even managed to go on with that gasket in place.

 

When mine broke, I replaced it with a Altrom cap from NAPA. Normally I prefer OEM parts, but given the number of people here who've had their Toyota cap shoot its spring down into the thermostat housing, I chose to go with a quality third-party replacement instead.

 

Exactly what I did too. I went with Sankei which is a very good Japanese brand. I had two OEM ones fail so this time I went with the Sankei