What is this squeal?

The ole '93 Hilux started making this sound intermittently lately. Any ideas? Hoping it is just a fan belt or something slipping?



cheers
 
I agree have you spun all the bearings with the belt off?


I wouldn't even know where to start! Changing a tyre is about my limit :oops:

Better not be a timing belt tensioner though, as the timing belt was replaced less than 10,000 kms ago.

There is an arm with a little tensioning wheel that comes off the alternator. That is not even touching the belt which comes off the alternator, I can just spin that little wheel freely by hand. Is it supposed to be like that?
 
Sounds like you should take it to someone who knows what they are doing then ;)

Yeah, you are right :D

Just seeing if I can get lucky and fix it myself, or get the young bloke next door to show me how - he is a great kid, very handy and humble & a keen fisherman. We talk fishing over the fence a lot.
He has just bought a Landcruiser & is selling his old Hilux (maybe a 2004 model?). Maybe I should upgrade......though I have a crazy sentimental attachment to my 27 year old rig. It only leaves the garage 3-4 times/month for fishing guiding mostly, so it is hard to justify spending more on a better 4WD.
 

MrPoopypants

Well-Known Member
The ole '93 Hilux started making this sound intermittently lately. Any ideas? Hoping it is just a fan belt or something slipping?



cheers

Hmm, hard to tell from the video. Doesn't sound quite like a belt, but they can make some funny noises when they get worn. Try tightening it fairly tightly (maybe with a small lever - spanner or something to lever it tight)
An old trick if it is still doing it is to touch the spinning belt with a bar of soap (dry! not liquid! :cool: Will often make the noise disappear, voile - replace the belt.
Also, visually check and touch the belt(s) to see if there are any bits where it is beginning to come apart, that can create some strange noises.
Wouldn't hurt to just switch the belt to see - always worth carrying a spare belt(s) anyway.
Watch your ears on the fan! :)
Good luck.
PP
 

Rusty Panels

Well-Known Member
It doesn't sound like a fan belt to me.

Hard to diagnose by video but I think it sounds like a bearing or bushing noise. Water pumps have bronze bushings and can sound a bit like that if they start to wear out, could also be alternator bearings or A/C compressor. You should be able to remove the belts and rotate all by hand. That will give you some idea of what the offending item is. I doubt if it's anything really sinister. I would avoid over tightening any belts as that causes premature wear. As a rule of thumb guide you adjust belts so that they can be pushed in at the longest span by about an inch (see diagram). Most modern engines use automatic tensioners so no adjustment is needed.

You also mentioned a pulley that had very little pressure on it. I'm guessing it's an idler pulley. They would generally have a fair bit of pressure on them to keep the belt tensioned. I would be checking that the correct belts were fitted after having the timing belt replaced.

So, my advice would be to remove the belts, then check any idler pulleys, water pump, alternator, power steering pump and the free wheeling part of the Air Conditioning compressor. If you can feel any tightness or anything feels gritty or lumpy then it may well be the culprit.

A brand new bearing will turn smoothly but will have a bit of resistance, a good bearing will turn smoothly with no signs of play or tight spots. Also the outer seals of the bearing should not show any signs of having leaked grease. Anything that feels lumpy or has tight or gritty spots when turning is worn.

Check your belts before refitting them and make sure they are in good condition with no damage or cracks. There are plenty of good diagrams and YouTube videos showing how to correctly adjust belts.

Good luck, keep us informed on how you go.

Cheers,
 

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Petunia

Well-Known Member
There is an arm with a little tensioning wheel that comes off the alternator. That is not even touching the belt which comes off the alternator, I can just spin that little wheel freely by hand. Is it supposed to be like that?
Yes, it is supposed to be like that because it is an idler to stop the A/C belt flapping round, the sealed bearing in this can dry out over time, to which I just unseal them grease re-seal and bingo. However, the noise you are experiencing does not appear to match 100% to this bearing?

The A/C tensioner is another semi free wheeling pulley/bearing located way down on the left [as you face the engine] under the A/C and Alternator. This has a nut to secure it, after tensioning with a tensioner bolt, this area may cause noise if the nut is missing? You mention that the timing belt has been changed, any bolt/nut may/may not have been tightened? It [the pulley] will not drop off surprisingly, just runs a little skew wiff.

After those 2, more indepth deeper doodoo will need diagnosis.
 

MrPoopypants

Well-Known Member
Yeah, all the above. Diagnosis by internet! I'd still eliminate the belts before moving on, if you can't isolate the noise by ear. Obviously, listen for any changes in the sound, with anything you do, one at a time, to figure it out. As Rusty said, tightening belts too much buggers them, so back it off again if it doesn't do anything and move on. If it works, replace the belt. Usually a bearing will make a consistent noise that varies with revs, belts will come in and out and vary, but of course there are always exceptions - otherwise it would be too easy!!
And, of course, this usually happens on a long weekend!! You'll find the noise will stop when you drive into a mechanics driveway. Even if you can't fix it, the challenge to figure it out has now been set! Beer and three mates with heads under the bonnet (socially distanced of course) should help.:)
Hey -maybe we need a video conference on it to give us all something to do! Virtual beers.
PP
 

Rusty Panels

Well-Known Member
Yeah, all the above. Diagnosis by internet! I'd still eliminate the belts before moving on, if you can't isolate the noise by ear. Obviously, listen for any changes in the sound, with anything you do, one at a time, to figure it out. As Rusty said, tightening belts too much buggers them, so back it off again if it doesn't do anything and move on. If it works, replace the belt. Usually a bearing will make a consistent noise that varies with revs, belts will come in and out and vary, but of course there are always exceptions - otherwise it would be too easy!!
And, of course, this usually happens on a long weekend!! You'll find the noise will stop when you drive into a mechanics driveway. Even if you can't fix it, the challenge to figure it out has now been set! Beer and three mates with heads under the bonnet (socially distanced of course) should help.:)
Hey -maybe we need a video conference on it to give us all something to do! Virtual beers.
PP
My diagnosis is never wrong when I have a beer in my hand! o_O
 

Rusty Panels

Well-Known Member
Overtight belts can damage what runs on them too. I had a little Kubota tractor and fitted what was supposed to be the correct belt to it. It was a really tight to fit so I had no added tension on it at all. 6 months later and the water pump started leaking from the shaft because the extra tension wore the bronze bushes into an oval shape. Expensive and unnecessary exercise. It pays to check and double check part numbers.
 

Petunia

Well-Known Member
I'm disappointed noone has brought in any suggestions involving duct tape, fencing wire or a gas axe!

Ok, if it makes you happy? That idler for te A/c belt slap is a P I A when changing the timing belt, there is one 10mm bolt hiding behind it.

Take an 8 inch angle grinder, [not 4 inch, less chance of going through the a/c condenser] and chop it off level with the side of the timing cover, this infact serves 2 purposes, 1: easier timing belt changes, 2: no noise from bearing ever again. [This is a true story, even down to the slight nick in a/c condenser ] :cool:
 

MrPoopypants

Well-Known Member
Ok, if it makes you happy? That idler for te A/c belt slap is a P I A when changing the timing belt, there is one 10mm bolt hiding behind it.

Take an 8 inch angle grinder, [not 4 inch, less chance of going through the a/c condenser] and chop it off level with the side of the timing cover, this infact serves 2 purposes, 1: easier timing belt changes, 2: no noise from bearing ever again. [This is a true story, even down to the slight nick in a/c condenser ] :cool:

Excellent!!! Hadn't thought of an angle grinder! And with battery tools can now be a bush tool!
PP:D
 
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