G20 burning smell slight knock

[500dolla]

today ive experienced a slight knock in my car maybe 3 per second, and the engine smells like something was burning, i checked out my oil and it was low so i refilled with 1 quart and i also filled my trans fluid with a quart too, i took it out for a test drive and the small knock and the smell remain any suggestions?

[nametakennow]

Check the oil again. If you've burned some up, you may have a bad piston ring or the like.

[500dolla]

even though my oil was low it ends up being my brakes that where so messed up, i was told my a mechanic that my e-brake line is rusted so my calipers are sticking, he says i need new rotars, pads, calipers , brake lines, and the ebrake cable. and it would cost me 800 dollars, i smell bull**** and a rip off

[nametakennow]

The knock was extra friction on the breaks causing noise or what?

Better than a dead engine.