Low pitch whine

[Ragingboner]

So I started hearing a random low pitch whine today. It's happens at idle though more so at low revs (under 1.5k). Can't hear the noise under full load.

I took it to my mechanic but by the time I got there (10mins) the noise has gone away. Went back to work and it started happening again and hour later and took it straight to him again. He had a look around and couldn't pin point it. Can't hear the noise in the engine bay, can ever so slightly hear it under the car but from inside the car you can hear it well.

My mechanic told me to keep driving till it gets louder so he can pinpoint where it's coming from.

Has anyone ever heard of an issue like this?

I uploaded a video of it though not sure if it can be heard clearly in the video.

https://youtu.be/8teuWN53H6U

[Pradlux]

G'day RB,
Mate all i could here was the air intake drawing in air. Maby check your air filter is clean and there is nothing blocking the intake. I have a piece of flyscreen gauze between my snorkel head and pipe to keep bugs out of the air filter and when it gets pretty packed it makes a noticeable whining noise. That's what i would be checking first anyway. I hope this helps. Good luck.

[banksy]

Probably the alternator.
Lots of people describe your symptoms where the noise starts and then stops after getting warmed up.
How many km on the ute?

[Pradlux]

Another thing to check is did you have your misses and or kids in the back for a while? I have found driving by myself stops annoying noises.

[wwwebfrank2234]

Anyone find out what this is?

[Frawls]

Check your exhaust flange are not missing any nuts, my sons had similar noise hey presto missing nut on the exhaust flange, new nut problem gone.

[wwwebfrank2234]

Sounds exactly like the top YouTube video.
New exhaust was installed over a year ago

[jpms]

Anyone ever find out where the Low Pitch Whine is coming from?
My Hilux started making the exact same noise (as in the video) this morning while pulling up to my parking spot at work.

[hiluxxury]

Anyone ever find out where the Low Pitch Whine is coming from?
My Hilux started making the exact same noise (as in the video) this morning while pulling up to my parking spot at work.

Alternator?

[jpms]

Anyone ever find out where the Low Pitch Whine is coming from?
My Hilux started making the exact same noise (as in the video) this morning while pulling up to my parking spot at work.

Alternator?

Thanks hiluxxury.

Yeah think so. Took the belt off when I got home and the noise was no longer there. I put it back on and then removed the square plug off the back of the alternator and the noise was not there, put the plug back on and noise is back.

Just for reference - noise is there at idle but is at its loudest at 1000rpm then tapers off and no longer there at 1500rpm or above.

2012 model, just ticked over 100000km, never been in water - strange the alternator is noisy, seems to still be charging ok. I'm glad it's not the turbo though.

[Rob_Wood]

Yeah if it is the alternator, then it's a dry bearing sound, can replace bearings easily enough, but same sound came from mine not long before AC compressor shat itself. Just keep an open mind before you start spending coin.

I know there used to be a mob in Kirrawee years ago that were great with diagnosis of this stuff years ago. If you're close enough I can find out if they're still there.

[hiluxxury]

Yep find a auto elec who will service the bearing and put in a solid pulley if it doesnt have one already.

Dont be fooled into get a chinese denso clone or anything an influencer pushes.

[Rob_Wood]

Yep find a auto elec who will service the bearing and put in a solid pulley if it doesnt have one already.

Dont be fooled into get a chinese denso clone or anything an influencer pushes.

Ditto

[jpms]

Thanks all, much appreciated. Hopefully, this will help someone too. Yeah not a fan of clone/fake stuff. I will get my alternator serviced and get a solid pulley fitted.

[241steve]

Ive brought a few aftermarket cheap alternators all of them have lasted more than 5 years.
Have I just been Lucky. I did about 40k k's on with the alternator I put on my prado.
https://www.ebay.com.au/str/trumpauto was the seller I brought them from I thought they were all right, no auto sparky around here is interested in rebuilding any toyota alternator Ive taken to them.

[Rob_Wood]

Ive brought a few aftermarket cheap alternators all of them have lasted more than 5 years.
Have I just been Lucky. I did about 40k k's on with the alternator I put on my prado.
https://www.ebay.com.au/str/trumpauto was the seller I brought them from I thought they were all right, no auto sparky around here is interested in rebuilding any toyota alternator Ive taken to them.

Back in the day, Bosch was the best, Lucas and others came in second. These days everything is out of China & you're buying a pig in a poke. Where are you? You want me to look at the mob in Kirrawee? See if they're still there?