Turum turum is a fun, onomatopoeic phrase that mimics the sound of a beating heart, similar to 'boom boom' or 'thump thump' in English.
In the song, Peso Pluma sings "tu cora no te hace turum turum" (your heart doesn't go boom boom), cheekily telling a girl that her current boyfriend doesn't excite her or make her heart race. It's a playful and catchy way to talk about romantic chemistry and a perfect example of how sound effects are used in Spanish music.
This song is all about trying to convince someone to leave their rich, but boring, boyfriend. Peso Pluma and Grupo Frontera sing to a woman who is a total "diez" [a ten], but she's with a guy who just isn't on her level. The boyfriend takes her on fancy vacations to places like Tulum, but the singer knows her heart isn't really in it. He says, "sé que tu cora no te hace turum turum" [I know your heart doesn't go boom boom]. It's a great line that gets right to the point: all the money in the world can't buy real excitement.
The singer argues that what he offers is much better. While the other guy has money, he gives her something more valuable. He contrasts them directly: "Él te compró un Rolex, pero yo te di mi tiempo" [He bought you a Rolex, but I gave you my time]. He's confident he can make her feel things that last, even if they're just hanging out in his apartment instead of a mansion. He tells her to just leave the old boyfriend, using the fantastic metaphor, "Que la comida se enfría / Cuando se descuida" [That the food gets cold / When it's neglected]. He's basically saying her boyfriend took her for granted, and now he's here to give her the attention she deserves.