Brian757
New member
Mine has 124,000 miles on it.
Help me figure out this noise please!
- Thread starter Tre_Mulliner
- Start date
Mine has 124,000 miles on it.
Tre_Mulliner
New member
The noise has been m.i.a. the past two days so i haven't had the chance to try the air intake selector idea... has anyone come up with any different ideas?
Brian757
New member
Aww man. Not to sound mean, but I hope it comes back. I figured I would wait until it got worse to diagnose the sound, but yours in bad and we still don't know what it is. So I want it gone before it drives me crazy
I will try to help you diagnose it. I just don't hear it long enough to find the culprit.
Tre_Mulliner
New member
Aww man. Not to sound mean, but I hope it comes back. I figured I would wait until it got worse to diagnose the sound, but yours in bad and we still don't know what it is. So I want it gone before it drives me crazy
I will try to help you diagnose it. I just don't hear it long enough to find the culprit.
I understand haha I thought I would let it go until it gets worse as well, but I guess mine is worse... I took the video around to a few of my mechanic friends and the were all baffled. They all told me that I need to leave the car overnight so they can hear it in person. My only problem with that it that is the noise not happening daily. With work and school its hard for me not to have a vehicle. I'll have to wait for my schedule to free up so I can get it in.
EatonKyleH
New member
Wow this is an odd one I must say! Anyway figured I'd run a few searches through IATN and Identifix and really this is all I could come up with. Figured if it happens again you could at least add it to the things you've ruled out! They didn't provide much description of the sound but I could see it being possible and can send you a procedure to force the pump to run and listen if you suspect it in the least bit. Anyway below is a straight copy/paste of it. May not help but hey more ideas to sift through right?
2002 Toyota 4Runner 3.4L, USA/Canada
Hotline Archive
With OEM Direct diagrams, components, TSBs, and R&R procedures
Number: 447166
Vehicle Application:
2002 4Runner 3.4
Customer Concern:
Noise coming from the anti-lock brake system unit right after the engine starts.
2002 Toyota 4Runner 3.4L, USA/Canada
Hotline Archive
With OEM Direct diagrams, components, TSBs, and R&R procedures
Number: 447166
Vehicle Application:
2002 4Runner 3.4
Customer Concern:
Noise coming from the anti-lock brake system unit right after the engine starts.
02_SE_Runner
New member
If the noise is there when the 4runner is on and not started and you have the AC/Heater on, it seems to me it would be the heater/AC blower motor or something squealing.
My question is, do you have the fan (Heater/AC) on when the noise happens? I had this noise happen to me once, and I immediately knew it was MY blower motor because it stopped when I turned off the AC.
My question is, do you have the fan (Heater/AC) on when the noise happens? I had this noise happen to me once, and I immediately knew it was MY blower motor because it stopped when I turned off the AC.
Brian757
New member
I completely understand. I do not have time to give it to a mechanic either. Also, I havent' heard it since last week, when at 6:00AM, it was a little chilly, around 40 degrees. No Alaskans/Northeners chime in on my "chilly" weather temp.
So I think I found a lead! I do not have a picture of what I am talking about, but I think it relates to this issue. If not, then I have ANOTHER sound... geez
So start your vehicle and put your A/C on. Mine was set to re-circulation. I heard a light ticking from the rear end. I went to the back of my truck and underneath, where the spare tire goes, is a box that has a bunch of wires running through it. It was making a ticking sound, but only when the compressor would kick on. Is this a pump going bad? When my A/C was on, it wouldn't make the ticking sound, but when you hear the motor drop idle, like something is pulling on it, (me - assuming its the A/C compressor kicking on) the ticking starts up. And when the engine sounds like the load came off of it, (the compressor kicking off) the ticking goes away. I can only take a picture of it to explain what I am talking about.
The reason this might be the culprit is because maybe a pump is going bad, and while it sits, maybe it is harder on the pump to re-circulate after sitting? I feel like it only does it to me after the truck has been sitting for awhile. I have no clue. But I would like to get down to the bottom of this, not only for me, but because the OP's sounds horrible and that's no way to enjoy a 4Runner.
There is no issue with my A/C or heater. I get freezing cold air, and really hot air.
I'm at work, so I cannot take a picture of this box, nor its ticking. But I certainly will tonight.
Last edited:
Tre_Mulliner
New member
Does anyone have any new ideas? Over the past few days i have been listening to the noise under the hood trying to pinpoint the area it is coming from. Im pretty confident that it have nothing to do with the ac blower. I feel like it has something to do with the braking system. The problem is i dont know what part. The brake booster is my first hunch. I dont know all the proper terms for what the 4runners have as far as brakes and would like to know (if someone could fill me in) but i am quite sure that the problem and noise lies in the braking system.
Tre_Mulliner
New member
Tre_Mulliner
New member
I completely understand. I do not have time to give it to a mechanic either. Also, I havent' heard it since last week, when at 6:00AM, it was a little chilly, around 40 degrees. No Alaskans/Northeners chime in on my "chilly" weather temp.
So I think I found a lead! I do not have a picture of what I am talking about, but I think it relates to this issue. If not, then I have ANOTHER sound... geez
So start your vehicle and put your A/C on. Mine was set to re-circulation. I heard a light ticking from the rear end. I went to the back of my truck and underneath, where the spare tire goes, is a box that has a bunch of wires running through it. It was making a ticking sound, but only when the compressor would kick on. Is this a pump going bad? When my A/C was on, it wouldn't make the ticking sound, but when you hear the motor drop idle, like something is pulling on it, (me - assuming its the A/C compressor kicking on) the ticking starts up. And when the engine sounds like the load came off of it, (the compressor kicking off) the ticking goes away. I can only take a picture of it to explain what I am talking about.
The reason this might be the culprit is because maybe a pump is going bad, and while it sits, maybe it is harder on the pump to re-circulate after sitting? I feel like it only does it to me after the truck has been sitting for awhile. I have no clue. But I would like to get down to the bottom of this, not only for me, but because the OP's sounds horrible and that's no way to enjoy a 4Runner.
There is no issue with my A/C or heater. I get freezing cold air, and really hot air.
I'm at work, so I cannot take a picture of this box, nor its ticking. But I certainly will tonight.
So the noise happened again today... Surprise surprise. However i was able to get a better idea where the noise is coming from. I left the key on the ON position and let it do its thing when i first start it. I popped the hood and waited for the noise to start. When it did i found that it was coming from the picture i posted. I put my hand on one of the canisters that is blow the brake fluid bottle and could feel the vibrations from the noise. I feel confident that, that is where the noise is coming from. Thoughts?
Tre_Mulliner
New member
any new thoughts.... the thread kinda died off. Help? 
alaskaflyer
New member
I have a set of newly acquired FSM's let me look and see if I can find anything. It sounds like you've found the source of the noise.
nicolasballia
New member
lmfao!! that sounds like a fax machine or something xD i bet thats a real pain in the butt... is it heard more inside the cabin rather than outside?
any new thoughts.... the thread kinda died off. Help?
Your year runner has an electric motor for brake assist rather than engine vacuum. Just next to the master cylinder is the motor and it will run when you first turn the key on to build pressure and will run intermittently while driving to keep the pressure built up.
Just an Idea. A picture was posted of the master cylinder and there is an electric motor there.
Tre_Mulliner
New member
When i first turn it on (first start in the morning only) it will cycle through five or six times. Is that normal? Throughout the day it only does it once. In the morning is when the weird noise occurs. Unless i pump the brakes a few times will it not happen. I think i need a new brake motor. That's my thought anyways. Every mechanic wants me to bring it in and leave it overnight. The noise doesn't happen everyday so i have a hard time actually doing that. However, i realize that it cant be fixed if i don't do that. I'm just hoping someone on here will have had the same problem and tell me their experience. Thank you for the reply though.
Tre_Mulliner
New member
Yeah i hear it more inside. Driver side.
Tre_Mulliner
New member
Anything out of the FSM?
alaskaflyer
New member
ADD kicked in and I got distracted. I will get to this soon.
imp:If you turn the key on, but don't start it you should be able to quickly move your ear near the master cylinder to see if that's where the noise is coming from. The brake motor will run when you turn the key on. Mine runs continuously for probably 10-15 seconds, stops for a bit and then runs again first thing in the AM. As I drive and use the brakes every once in a while I can here it running. But not much over the sound of traffic, the radio etc.
