Have you tried brushing your teeth and using mouth wash?yeah, it doesnt go away.
It's probably something going around because I've had the same thing for about 3 weeks. And I have a cough.
I've had tonsil stones before but that doesn't seem to be what this is. The taste reminds me of the smell of a new car or something. It definitely is originating from the very back of my mouth because I typically only taste it when swallowing.