Where in the bible does it talk about false teachers?

Answer 1

If, by "pastoral epistles," you're referring to I and II Timothy and Titus, they all do.

1 Timothy 6:3-5 - If anyone teaches otherwise and does not consent to wholesome words, even the words of our Lord Jesus Christ, and to the doctrine which accords with godliness, he is proud, knowing nothing, but is obsessed with disputes and arguments over words, from which come envy, strife, reviling, evil suspicions, useless wranglings of men of corrupt minds and destitute of the truth, who suppose that godliness is a means of gain. From such withdraw yourself.

2 Timothy 4:3, 4 - For the time will come when they will not endure sound doctrine, but according to their own desires, because they have itching ears, they will heap up for themselves teachers; and they will turn their ears away from the truth, and be turned aside to fables.

Titus 1:10, 11 - For there are many insubordinate, both idle talkers and deceivers, especially those of the circumcision, whose mouths must be stopped, who subvert whole households, teaching things which they ought not, for the sake of dishonest gain.

[NKJV]

Answer 2

(2 Peter 2:1) 2 However, there also came to be false prophets among the people, as there will also be false teachers among YOU. These very ones will quietly bring in destructive sects and will disown even the owner that bought them, bringing speedy destruction upon themselves.