I have a 2018 Camry (less than 5K miles), and when it's in gear with my foot on the brake, it has a loud idle. The first time I heard it I was in line at a McD's and I thought to myself, "I hope that it's that guy's car. That sounds bad." I just assumed it was his, seeing I had 4K miles on my car. I was in my driveway, and my husband came out and asked if it were my car making the loud noise. Sure enough - it was the same idle noise that I heard in the drive thru. It's a loud clicking sound when in drive or reverse with the a/c on.

The Toyota dealer is saying it's nothing - just normal noise. However, the fact that both of us thought it sounded off on separate occasions is giving me red flags. Especially because our 2017 RAV and my old Yaris didn't make this noise.

  • Given that your car is new I would certainly be taking it back to the dealers. Helpfully they should have other cars of the same model and newness. If it’s a normal noise then they can demonstrate these other new cars also making the same noise upon following your instructions to reproduce the noise (it will help if you can reliably make your car do it). If the other cars don’t make the noise then you can leave you car there for repair and take a courtesy car :)
    – Caius Jard
    Jun 4, 2019 at 3:30
  • ticking noise can be a simple tappet tick (from valve lashes) you usually get in dohc engines. keep the engine running and try to pin point where exactly the noise is coming from and go from there. Jun 7, 2019 at 4:18
  • Newer engines with direct injection can make clicking noises from the high pressure fuel injectors, which is normal. Not sure if your RAV4 had direct injection, but the older Yaris probably didn't. Without hearing the noise it's hard to comment further. Jun 23, 2021 at 15:52

2 Answers 2


The ECU of a car typically increases the idle speed to account for the AC being on. It increases the load on the engine, so raising the idle keeps it from stalling. Does it make the same noise in neutral or park?

  • This is more of a comment than an answer, particularly as it asks a question
    – Caius Jard
    Jun 4, 2019 at 3:27

Does your car have the 2.5 liter 4-cylinder engine?

I have a very similar Toyota 2.5 liter engine in my 2016 Toyota RAV4 hybrid, although it is the slightly modified Atkinson cycle 2AR-FXE and not the regular 2AR-FE.

I find the engine is very loud and vibrates a lot when idling. The "idling" of a hybrid car is somewhat different than the "idling" of a non-hybrid car because the hybrid car is charging the battery as it "idles", thus increasing the load on the engine.

However, an air conditioner could do just that -- increase the load on the idling engine on your car.

Probably the reason for the rough and loud idling is that these 2.5 liter inline 4 engines are very large for the inline 4 configuration. The configuration is inherently unbalanced and thus noisy vibrations are to be expected. For example inline-6 would be far smoother because it's inherently in balance.

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