Loud buzzing noise from under the dash?

[The Cold War Kid]

I do 90% of my own work of course. Only been working on cars and motorcycles for 48+ years. I don't know about the heat selector motor but I can say when I bled the brakes on the rig the other day; I had to turn the key on for this motor to kick in so they would bleed properly so that confirmed it's a brake motor. I provided a link to a rebuilt one on ebay for reference in my previous post.

I will keep your issue with the heater door in mind though if I hear any motor noises coming from the center of the dash. That is where you heard it right? Center dash?

Yeah - seemed to come from dead center. The thing is just above the passenger's left knee. Mine really raised he77 - lol.

 

[compass]

The noise comes on when I start then runs for 10 seconds or so. Maybe a vacuum pump? I have no idea.

The heater control does not work and the air passages are very slow to change with the control. Maybe this is something to do with the noise?

Anyone have this problem?

I just had this similar problem and came to this site for help. This noticeably loud buzzing noise would come on after ignition and last for about 20-30 seconds. My heater would also only blow cold air with no heat on any setting. There are many posts on this forum and a few YouTube videos on the topic. Many of the problems center around the blend door actuators behind the dash to the left of the glove compartment. Before removing the actuator servo motor(s), which can be a hassle, simply disconnecting the wiring harness to the servo motor should determine which one is creating all the noise.
After I found which one was making the buzzing sound, a visual inspection revealed that the linkage appeared to jammed against a nearby metal bracket. I sprayed some lubricant on the linkage and gently pried it loose while the controls were on the heat setting and the linkage popped free and rotated several degrees. Sure enough, after I started the vehicle I had warm air to the vents!
Even though it seems that my heating (and cooling) seem to be working okay now, I wouldn't be surprised if there is some damage to the servo motor which may require replacing eventually. For now I am completely satisfied with the results. I only needed to remove the glove compartments, lower skirt and plastic floor duct tubing to get pretty clear access to the actuators. All together, about an hour worth of work but, again, I didn't replace any of the actuators- yet.
I am really glad that I found this site and registered today. Thanks to all who posted on this subject making it easier for us with the same problem.

 

[roger65]

Newer 3rd gen 4runners have the expensive brake master pump which is 1/2 price of the 4runner's market price!
If you hear the sound for 30 minutes or less, that is normal as it is filling the booster with nitrogen gas. If it takes longer and/or hear the buzzing sound all times, then something is wring with the system and most likely it is not going to be a cheap repair.

My daughter has a 96, 3.4, awd, that makes a buzzing noise after it is shut off. happens every 8-12 seconds and last for a couple seconds. Seems like it is under hood on drivers side but I cannot isolate it. Could this be the buzzing? I have touched all the relays and fuses in the area and nothing is vibrating. It stops after a few minutes.
I don't have enough posts to make a new thread so I am highjacking relevant threads I see.

 

[Riceye]

My daughter has a 96, 3.4, awd, that makes a buzzing noise after it is shut off. happens every 8-12 seconds and last for a couple seconds. Seems like it is under hood on drivers side but I cannot isolate it. Could this be the buzzing? I have touched all the relays and fuses in the area and nothing is vibrating. It stops after a few minutes.
I don't have enough posts to make a new thread so I am highjacking relevant threads I see.

What you're hearing is the fuel evap assy equalising pressure. It is located near the driver's side strut top hat in the engine compartment. I've heard that unscrewing the gas cap will make it stop, but it will happen the next time you start up.

It's harmless. I seem to recall a mod that was done by Habanero that involved a dry mustard can. Lol

 

[Toy2play]

What you're hearing is the fuel evap assy equalising pressure. It is located near the driver's side strut top hat in the engine compartment. I've heard that unscrewing the gas cap will make it stop, but it will happen the next time you start up.

It's harmless. I seem to recall a mod that was done by Habanero that involved a dry mustard can. Lol

You would be correct, also will happen randomly as the day gets hotter. At first I thought it was a bee trapped somewhere under the hood and kept buzzing. I read there was a recall on this problem and that they replaced or added something to make it stop, by 97 model they corrected the problem. I guess the recall part they added is long gone and no longer stock the part.

 

[Riceye]

Read post #1097. Mustard can and some hose/bits.

habaneros-1996-4runner-build-up-thread

 

[BSG_75]

Once the noise shuts off after ~10-30 seconds or so, pump the brake pedal 5-15 times. If the noise starts up again, that's your brake booster/pump which is attached to your master cylinder. If you do feel something is wrong with it, PM me, there are some sub assemblies that you can buy to save some money potentially. I recently had to replace the whole kit and kaboodle on my 2002 after much diagnosis and research.

If the noise doesn't reoccur no matter how much you press the brake pedal, it was probably your antenna motor or something else.

Mine almost sounds like a motor/vibrating sound in the speedometer dash area, then ends with an audible click on the passenger side. Does it when I start the truck and often each time I brake, same length and sounds. Maybe it's this? Never did it before, until I had brake work at Toyota! hwell::shrug: **(But I wouldn't call it loud, but noticeable)**

 

[ChelleDawg]

Buzzing sound in glovebox area

I'm new to this forum but so glad I have found this thread. I have a 2016 4R limited and have just recently started to hear a buzzing sound whenever my heat is on. It is coming from the glovebox area but when I turn my heat off, it immediately stops. Sounds like a cd is constantly spinning in my glovebox or the buzzing sound a computer makes ... is this what you guys are hearing?

 

[Bad Luck]

I'm new to this forum but so glad I have found this thread. I have a 2016 4R limited and have just recently started to hear a buzzing sound whenever my heat is on. It is coming from the glovebox area but when I turn my heat off, it immediately stops. Sounds like a cd is constantly spinning in my glovebox or the buzzing sound a computer makes ... is this what you guys are hearing?

This is the 3rd gen 4Runner section (1996-2002). You need the 5th gen section: https://www.toyota-4runner.org/5th-gen-t4rs/ but try using this 5th gen specific google search first: site:[url]https://www.toyota-4runner.org/5th-gen-t4rs/ - Google Search[/url]

With that being said, if the noise goes away when you turn the blower motor off then it's most likely the blower motor. If it makes the noise when you change the temperature to cold then it would narrow it down further to being the blower motor. DISCLAIMER: I don't have a 5th gen and they have a lot more electronics and modules than any 3rd gen does.

 

[ChelleDawg]

This is the 3rd gen 4Runner section (1996-2002). You need the 5th gen section: https://www.toyota-4runner.org/5th-gen-t4rs/ but try using this 5th gen specific google search first: site:[url]https://www.toyota-4runner.org/5th-gen-t4rs/ - Google Search[/url]

With that being said, if the noise goes away when you turn the blower motor off then it's most likely the blower motor. If it makes the noise when you change the temperature to cold then it would narrow it down further to being the blower motor. DISCLAIMER: I don't have a 5th gen and they have a lot more electronics and modules than any 3rd gen does.

Thanks!!!