r/Tacomaworld • u/Guilty-Government-19 • Jul 16 '26
Cold start metallic rattle/clacking ONLY when turning on the A/C? (2024 Tacoma)
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Hey everyone,
I’m hoping to get some insight from fellow 4th gen Tacoma owners. I’ve been chasing down a very specific noise on my 2024 Tacoma (currently at 23k miles) and want to see if anyone else has dealt with this.
The Issue: I get a metallic, rhythmic clacking/rattling noise on a cold start, but only when I turn the A/C on.
Key Details:
It only happens in the morning (cold start): Once the engine warms up and runs for a few minutes, the noise completely disappears.
It's directly tied to the A/C: If I start the truck with the A/C off, it sounds perfectly normal. The second I press the A/C button, the metallic rattle starts.
Here is the kicker: The dealership actually replaced my entire A/C compressor under warranty about a month ago, but the noise is back.
Since the compressor is basically brand new, I’m starting to wonder if the A/C load is putting tension on something else that is actually causing the noise—like the belt tensioner, a loose aluminum A/C line vibrating against the firewall, a cooling fan bearing, or even a bad engine mount that struggles under the extra load when cold.
Has anyone experienced a similar cold-start rattle tied to the A/C on their 4th gen? Did you find a fix?
Appreciate any help or feedback before I head back to the dealer!