Air Conditioner Noise

New member here. Lurking since 2007. I promise I searched first, but found no answer.

When I turn on my A/C I am getting an odd noise that I can only hear coming from underneath. It is sort of a squeal, but more of a rumble whenever the compressor kicks on. It is LOUD. I cannot hear it in the engine compartment and it is not heard in the cab. The A/C blows hard and COLD, but the noise is making me nuts.

Any ideas?

Carp

 

I have similar noise but only when truck sits idle with AC on for some time. once I start driving it seems go away. I had not time to troubleshoot but have bad feeling temp is affecting the AC unit.

 

Can you define "underneath"? You can't hear it under the hood or inside the cab?

The main culprits for AC noise are belt, AC clutch, AC compressor and blower motor. The first 3 should be heard under the hood while the last should be more prominent inside the cab.

 

FreeHeel

Thanks for the response. Like BlueT, it is worst when the truck has been sitting at idle. I notice it standing next to the driver or passenger door. When I lean down it gets louder. I got underneath and it is loudest. In the cab there is no noise. Under the hood there is no noise.

Carp

 

There is a TSB for AC and another thread where a noise fix was accomplished...I think it was blower motor or bearings.

 

Here ya go. This might apply to what you're hearing......................

http://www.tacomaworld.com/forum/at...549-reduced-hvac-flow-tsb-t-sb-0072-09-1-.pdf

 

Does the noise come and go while sitting at idle or is it continuous? Does the AC continue to blow cold air while making the noise at idle?

 

Noise seems to get louder as truck stands still. To the point that no longer you can hear engine. No change in air temp inside the cab, at least not that I could feel. once truck is moving for a minute noise slowly goes away and does not show up until again gets parked for few minutes while idling with AC ON. Also noise just dont start but rather progresses from AC compressor noise (gets slowly louder and louder)
Its the first year that my truck did that so i am curious as what is happening. Funny thing is my other car did exact same thing this year and it is Nissan so go figure. None had been to the dealer and nobody touched AC.
I have pink clutch on the fan so I would think thats the tow package but now I am wondering maybe we need heavier grade of oil in the fan clutch ... ???

 

x2 Exact same thing, compressor is on that side underneath so that's why we probably hearing the noise from there.
Is your truck started acting this year ???

EDIT: Funny thing Carp your truck is 2007 also ...

 

Kinda stumped on this one, sorry. Initially I was thinking AC clutch as if the "air gap" is out of whack (too wide) it can cause the clutch to not properly engage. This can give you the squeal type noise you describe. Doubtful this is your problem though as your AC would not continue to blow cold air as the compressor is not spinning.

Wish I could be of more help.

 

I've been noticing a LOUD belt shutter lately produced the A/C turning on after my 09 Sport has been idle for several hours. Since I have a manual, I thought it was the clutch but i have come to find out it is when the A/C engages under the hood several seconds after starting the truck. Has anyone else had this issue? Anyone have any suggestions for a correction? Thanks!

 

Based on your description, I don't fully understand your problem but take a look at this http://www.tacomaworld.com/forum/technical-chat/94709-air-conditioning-blues.html thread. If it doesn't describe your problem, post back with specifics and I'll see if I can help.

 

I'm having a similar issue as BlueT. Mine is really only when idling or sitting and idling with the AC on. First time I heard it I immediately thought it might be the AC and turned it off and the noise quits. It's more of an audible vibration rather than a squeal. I can hear mine by the passenger side when I'm out of the car too.

 

Pink fan clutch is not an indication of tow package. Most (all?) Tacoma's have a pink fan clutch.

I have this exact same problem and only noticed it for the first time this week. Turning off the AC or reving the engine slightly above idle makes it go away. An audible vibration is a very good description of the noise I hear.

 

http://www.tacomaworld.com/forum/2n...-source-ac-compressor-clutch-grind-noise.html

Read my post in this thread. Just fixed my noise.

 

^Cross post/quoting from the thread he was talking about. I'll check my Taco and see if that's the same problem. What bolt is it? Is it obvious?

 

It was the top bolt holding the alternator to it's mounting bracket. It's easy to see from under the hood, but I had to have just the right lighting on it to see that the washer was spinning.

The noise was almost like a couple of plastic gears grinding.

 

An old post - yes - but I thought I would comment here rather than start over as there is some history of an "air conditioning noise" established in this thread.

Next Tue. I have an appointment with a local Toyota dealer to address this issue. Still have 3 months left on my 3 yr/36K warranty.

BUT...it is NOT the A/C in my case. The situation(s) above sound similar to mine.

Truck has to be fully warmed up. More likely to occur when it's hot outside. If I return from a 20-30 mile highway trip AND let the engine continue to idle with gear selector in P - an oscillating noise will develop and become louder the longer I let the engine idle. If I put gear selector in D - the oscillating sound drops off

I decided to pull the metal shroud down underneath(4/12mm bolts) and put a mechanics stethoscope on the compressor while engaged. I did not hear this oscillating sound nearly as well when underneath the truck. Put stethoscope on compressor. I'm not hearing it.

I go top-side and start poking around with the stethoscope. The sound I've described is coming from the ALTERNATOR - not the compressor. Stethoscope confirms this.

So - in summation - engine fully warmed up - a/c on - gear selector in P. Engine allowed to idle for awhile after a drive. The longer it idles - the more noticeable the oscillating sound becomes. Turn off the A/C and the sound stops.

It would seem that when things get hot with A/C on - alternator is having a issue. Resting battery voltage is 12.75V - engine off 10 hrs - cold engine idling with all accessories off - voltage is 14.02V - hot engine idling with all accessories off - voltage is 13.4V. I'm not too impressed with this 13.4V and all accessories off. Therein may lie the problem.

I'll find out next Tues. and report back.

Update:

Took truck to dealer this A.M - 6/20/17 - short story - dealer tech said it was the compressor. Toyota's eating this one so I'll go along with it 'til things prove otherwise.

Update:

Took truck back again this A.M - 6/21/17 - new compressor installed - not the front coil/clutch - just the compressor. Still hearing oscillating sound after it's warmed up idling in P - but - let it idle long enough and the oscillation diminishes significantly. While the oscillating sound is more pronounced - I still hear it coming from alternator - mechanics stethoscope on alt.

Update:

Took truck back again this A.M - 6/22/17 - got the dealership Fixed Operations Director involved - highest ranking service mgr. in a Toyota dealership. He got inside truck to listen. He can hear the oscillation with a/c on - truck in PARK - engine idling. Gets shop foreman involved. They want to bring in a Toyota Field Technical specialist. They claim it's not the alternator and are stumped at this point.

Update - 07/13/17:

Took dealer almost 3 weeks to get the Toyota Field Technical Specialist to come around. I got tired of waiting and opened an issue with Toyota Customer Relations. The Field Tech showed up. Left truck with him and local shop foreman.
They replaced the following:

-90916-A2001 - Serpentine belt
-16620-31013 - Belt tensioner assembly
-16604-0P011 - Idler pulley #2
-16603-0P030 - Idler pulley #1

Both pulleys are near tensioner - one above; one below. There is another idler pulley to the right of the crankshaft/water pump(as seen seated in drivers seat). That was not changed.

The oscillating sound disappeared. No longer hear it in the Alternator with a mechanics stethoscope.

Sad that a dealership had to bring in a tech. spec. to determine the problem was a belt/tensioner/2 pulleys and that Toyota had to eat a $559.93 compressor replacement. There was never anything wrong with the compressor. Fixed Ops Dir. said the field tech. could see some pulley wobble.

I've put about 150 miles on the truck since this latest fix. Doing much better.

See post #20 in this thread for belt/tensioner/pulley layout:

https://www.tacomaworld.com/threads/idler-pulleys-tensioner-pulley-serpentine-belt.280576/

 

I know this is old but I didn't see an answer anywhere in this thread and I think I have one for future searchers.

Sounds like what OP is describing is the gears in the manual transmission clattering when the AC compressor is activated. Mine has always done it and I've read about several others who have heard the same thing, I do believe it is normal. It only happens at idle when the gears are not under any load. I don't know exactly why it happens, probably something to do with the idle speed when AC is on or a vibration at just the right frequency. You can test by pushing in the clutch at idle with the trans in neutral when you hear it. If the sound goes away, you have your answer.

 

To me the issue sounds like high head pressure for the A/C pump.

The compressor can't turn on right away because the down stream pressure is too high. When the truck is moving, extra air is transferred across the condenser, thus lowering the head pressure. This allows the A/C pump to turn on normally or close to normally.

Usually a low refrigerant charge will be the basis of this issue. Quite often you will hear a thud or thump from the A/C when the clutch is energized. You may see some serpentine belt residue around the A/C clutch as well, this is from the belt momentarily slipping.

Low refrigerant is a known issue right from the factory with Toyota trucks..