Squealing / Chirping Noise when driving and warmed up

My 4 Runner has never caused me any grief but now that my new one is coming it has started making a squealing, chirping noise.

I have replaced the front/back brakes, rotors and front calipers. Still the noise is there. I have taken it to Toyota, 3 other mechanics and nobody knows what the problem is.

 

4runners have a few common easily-solved sources of noise. Hopefully yours is one of them. Could you describe your noise more specifically?

 

it is really hard to describe it, sounds like chirping squealing sound. I have a recording of it but this forum will not let me upload it. DO you have an email address I could send it too?
It happens when the SUV has been driving for a bit, (warmed up) it is not consistent at all and it is getting louder.

 

As in, when does this noise happen? Driving, turning, braking, backing up, certain speeds...? Or all of the above?

 

It makes it all the time, when driving. No difference in sound from turning or going straight. But if the truck has been sitting for a night it takes a bit for it to warm up before making the noise. again, if I could get your email I can send you the sound

 

Here is the link to the sound that mu truck is making

https://youtube.com/shorts/2KUc1Q-xSTc?feature=share

 

https://youtube.com/shorts/2KUc1Q-xSTc?feature=share

 

Interesting does the noise change if you apply the brakes or serve back and forth or slow down or speed up? It sounds like your moving at good speed could it be some sort of wind noise? Finding some way to affect the noise will go a long way in diagnosis.

 

No it makes no difference if I apply the brakes or not or slow down or speed up. It only starts after it has been running for a bit. We have been playing with wind noise to see if that is the problem but so far not found the problem. It is driving me crazy, and it is getting worse as the noise is more often and before it would take the vehicle time to warm up now it starts within a few minutes of driving it. Mechanics are saying it could be front output seal flange or the transfer casing, or the front differential. But nobody can guarantee that is what it is.

 

No when I am stopped it doesn't make that noise, only when driving. After work I will take it driving in reverse and see if it still makes the noise.

 

Ok so speed affects the noise. Listening to the sound again it's inconsistent nature still makes me think of wind noise. I would think a dry seal would be a more consistent noise. You should be able to affect some change if it was a metal to metal contact. Tuff one for sure. Any recent Mods?

 

No speed does not affect the noise. Yes, it is a tuff one for sure. lol I appreciate all your help and thoughts.

 

If it’s stopped, it doesnt make the noise. What about at 5mph? 10mph? At what speed does it start happening? Does this happen on perfectly smooth roads?

 

Also, I’ll go ahead and mention the common sources. Your noise might be coming from one of these.

The rubber splash shields in the front wheel wells will make weird noises. Lots of people find a way to secure them better with new clips, or even zip ties. They move around and make the weirdest noises when you start getting a little speed.

The other possibility is the metal latch on the hood. Clean it off with a paper towel and put a tiny bit of grease where shiny spots indicate it makes contact.

The third is the rubber stops on that make contact with the corners of the hood. Wipe them off with a bit of water. Clean the spot on the hood where they make contact.

 

I have a a similar chirp on my LC I'm trying to track down. So annoying to say the least. Good luck and please let us know what it was if you figure it out.

In the driveline it could be:

U-joints/driveshaft
Wheel bearing
Bad diff or low on fluid (unlikely)

 

I’m gonna throw out one that hasn’t been mentioned yet, but is the first thing I thought of when you described your problem:

check your fan clutch

 

What he said ^^^^^^^^^^^^^^^^^^^^^

That or a belt tensioner pulley.

 

The audio makes it sound like it happens with some speed on roads with some bumps. It sounds like motion/body movement is needed to make the sound happen. That would make me suspect something rubbing or jiggling around. Not something mechanical like a differential,transfer case or fan clutch or belts.

 

Idlers too, but if the sound doesn't change with speed or rpm, I'm not betting on it.

 

Guessing no mods then? Wasn't there an issue with inner fender well or splash shields doing something like this?

 

try without belt

 

If it doesn't make noise when just sitting there how can you drive it without a belt. Just saying.

 

I mentioned that one as one of my top suspicions, just because it’s almost always the reason for the oddest sounds on otherwise new/solid 4runners. The hood latch too. After one day of gravel roads, my latch starts to make weird sounds on little bumps.

I hope the @Ahilton1 doesnt start replacing parts like differentials and transfer cases just yet.

 

The hood is another good bet. I had that before

 

Why remove the belt? Just reach in there and try to wiggle the fan. I lean towards fan clutch because he states the problem occurs after the engine is warmed up

 

Mine did that right after I did my rear brakes (pads only). It sounded like the wear indicator on the left rear. Could have been the fact that I neglected to apply grease to the shims. It eventually stopped.

 

Thank you all for all the great Idea's, I will be reaching out to my Mechanic to go over all these great idea's. I did some driving on the weekend and played around with the truck. It starts to make the noise at 8KM per hour. It does it when I am in Reverse as well. I have lubed a few things that have been mentioned above. We are looking at Front output seal flange and or Transfer casing. I don't want to start replacing everything as we really don't know what it is.

 

Get a mechanics stethoscope. You can then pinpoint the noise. Sounds like a bearing that is failing to me. Could be idler, alternator, tensioner bearing.

 

Yeah, but she has to be driving...

 

I missed that it doesn't happen while idling.