Can I use the uncountable noun "news" countably?

Hello everybody,

I'm from Hong Kong and sometimes I heard that some said,

"I've A good news for you"

Is the sentence grammatically incorrect?

I know "news" is an uncountable noun and shouldn't use "a" in front of "news", but I also know that some uncountable nouns can be used countably and vice versa. For example...

"We have plenty of time" ("time": uncountable)
"We have a GOOD time" ("time": countable noun referring to a more particular (not general) meaning)
(What we have is a GOOD time, not a bad time)

I wonder if "a good news" is grammatically acceptable.

Thanks.