3rd Gen Tacoma A/C Noise

Greetings all! New member here. I purchased my 2018 TRD Off Road A/T in the middle of April, and overall I love the truck (coming from a 4th gen 4Runner SR5). However, since Day One I've had cabin noise issues with my air conditioning. Two different sounds that seem to be related. Here's what happens:

When I'm running the A/C and the truck is actively moving or accelerating, a very noticeable "sighing" sound can be heard emanating from the dash. It actually sounds like Darth Vader breathing and is VERY annoying. It cycles about every 4-5 seconds. I'll hear the sound for 4-5 seconds, it will stop, then it will come back in 4-5 seconds. Lather, rinse, repeat. The timing between incidents can be variable, but it happens ALL THE TIME when I have the A/C running. Particularly noticeable on the two lowest fan settings, probably because the fan noise on the two higher settings drowns it out. If I turn off the A/C button in the middle of one of these sighs, the sound stops instantly.

The OTHER sound issue is related, but doesn't always happen. When it does, it's typically during acceleration. It's a whistling sound, almost like the sound you hear when you blow across the top of a half-full beer bottle, and it coincides perfectly with the Darth Vader sigh. It can be quite loud. My wife heard it for the first time this weekend and said "Wow! That's not normal!", so it's not just me.

Neither of these issues are evident if the truck is sitting at idle with the A/C running, only when it's actually being driven.

This is making me nuts! I've taken it to the dealer once, with the same detailed info that I've presented here, and they told me they couldn't find anything wrong. The mechanic asked that I put another 1K miles on the vehicle (it had 500 on the odometer when I took it in) and bring it back if the problem was still there. Well, it IS still there and the whistling sound has actually become worse. I'm going to be taking it back to the dealer next week for this to press them on it, and I'm also going to take a different Taco for a test drive to see if it has the same problem.

No other vehicle that I've ever owned has had an A/C system that sounds like this, and I can't imagine it's by design. Has anyone else here experienced this issue? If so what was the fix?

 

Oh great, more 3rd gen Tacoma quirks that I now have to obsess about looking for in mine.

Mine does the whistling noise, but I've never associated it the the AC. Maybe turn up the music??

 

Yeah they all make the Darth Vader Exhaling sound, you will get used to it.

 

Well that's disappointing to hear. Like I said, this is the only vehicle out of the 11 I've owned that has an A/C system that sounds like this. My wife's 2016 4Runner doesn't do it either. Thanks a million, Toyota.

 

Mine only does the whistling sound first thing in the morning when I turn the air on as I am pulling away from the house. Never does it again after that. I always have the AC on, recirc off, temp about 2 notches above max.

 

I'm 64 years old and have quite a bit of hearing loss which can be a good thing sometimes . My wife on the other hand has incredible hearing. In fact she is always hearing things that I can't. She has never mentioned hearing any odd noises coming from my truck, so no they don't all make it.

 

I think it may be the vacuum actuated blend doors moving so it's just the air sounds, most people probably don't pay attention to it or just get used to it.

 

That's a good guess. I wouldn't mind it so much if it wasn't so LOUD. I can hear it above human speech from the radio when I'm driving below 40. I'm still taking it back to the dealer and will at the very least do that test drive to compare how mine sounds with a different truck.

 

A/C??? We need no A/C in Az.

 

Do you have the Dual Zone Climate Controls?

 

I do not. Decided to pass on the Premium Package due to headroom issues with the moonroof, so just got the Tech Package.

 

The blowing across a bottle sound may be the lower control arm kazoo. It typically happens at lower speeds. Check your lca’s for plugs.

 

Thanks for the info, but it is most definitely coming from the A/C. If I turn off the A/C while it's whistling, the sound stops instantly.

 

It is definitely the AC, i believe it is the blend doors, sounds like a pressure release. After you shut the truck off and sit for a few seconds you can actually hear it moving too.

 

Mine does it too. Sounds like some harmonics in a refrigerant pipe. Maybe future models might get a muffler somewhere. Doesnt bother me. If i had to compare it to something, it kind of sounds like a steam whistle under the hood.


EDIT. Mine does it most when its very hot outside, and under acceleration. The compressor seems to really shake the engine when cycling on vs. Other cars i have driven. On a hot day compressor engagement feels like a misfire. These use the new refrigerant at higher pressures, maybe its that?

 

Wow, that’s really interesting. Mine never did that, so I’m kinda surprised at that.

 

What you are hearing is the refrigerant expanding into the evaporator in the dash everytime the compressor cycles on. It is expanding and cooling (as that is how the refrigerant works). In my previous vehicles (specifically a GC), this was an indication of slightly low refrigerant. Even my 89 Honda does it. In the Taco, I don't know if that holds true. You may want to have the dealership check the refrigerant levels. I bet if they add just a couple more ounces of refrigerant, the sound will mostly go away.

 

That's because the truck automatically turns on fresh air when you shut it off to keep the AC system from staying damp inside and getting mildew/mold

 

I dont think this truck or any toyota has used vacuum blend doors for quite a while. Thats an old Merican thing from my experience. It was so sarisfying hearing the pressure release when shutting the a/c off.

The auto ouside air when shutting truck off is genius though. I always did that manually before shutting off the a/c to reduce moldy smells.