High pitch squeak at 2100 PRM

In addition to @DrRobin's belts, pulley, and TO bearing, I would add to check your engine and (especially) gearbox mounts.  The latter is failure-prone on these cars after a certain age.  And if the noise only happens under load, that may be your clue.  Easy job.

If it were me, at that mileage I would plan to replace the belt(s) anyway unless I know it has been done recently, and I would have a good, long look at the harmonic balancer aka crank pulley too.  But that really depends on your attitude towards doing things as PMs vs spending money only when unavoidable.

DrRobin wrote:

The two classic things which squeak on most cars are the belts (your Jimny might have two) or the clutch (thrust bearing), although the squeak these make tends to change in pitch.

If it’s rpm and not speed related then it has to be engine (before the gearbox) and my first checks would be the belts.

A few questions

Is the squeak worse after starting?
Is it worse if turning?
Is it worse in the wet?
Do you have aircon, is it worse with this on?

The belts are quite easy to check, but to the untrained eye do appear to be quite tight. Once they start squeaking they wear and are more prone to do it in the future.

The other problem on jimnys is the belt crank pulley, it has a rubber cushion drive and they wear, this first makes the pulley run off centre, then it collapses, so that’s worth checking with the belts.

Thanks @DrRobin

Yes, RPM related and not speed. 

Is the squeak worse after starting?
- The sounds is only once at that RPM range, not during starting. Though, every 10th start or so there is a sliiiiight belt squelch upon first firing/starting, that goes away within a few quick seconds. This happens very rarely. 
Is it worse if turning?
- No. Wheel direction makes no difference.
Is it worse in the wet?
- No
Do you have aircon, is it worse with this on?
- I have Aircon. No, it does not make the sound better/worst when it's running. Has no effect. 

The squeak is a constant tone if you hold the RPMs at 2100-2200, and will continue to make the sound until the RPMs raise or lower, or push in the clutch. And the sound only happens when you are on the gas, never stationary or in neutral.

I mentioned checking the belts to the shop, and they said they all looked good. 

I will have a look at the belt crank pulley, see if there is any play before starting, or any wobble while running. 


Getting a recording is proving very difficult for the microphone to pick it up, and most roads around here are cobblestone... which is not helping   Will keep trying. 

 

When you hear the belt squeal at start up is it the same or similar sound as to the one at 2000 rpm?

You mentioned the squeak at 2000 rpm, every gear, does it do it in neutral or only when moving?

If it’s only when moving is it under load (I.e. engine accelerating or engine keeping a constant speed) and does it squeak under no load or deaccelerating?

DrRobin wrote:

When you hear the belt squeal at start up is it the same or similar sound as to the one at 2000 rpm?

You mentioned the squeak at 2000 rpm, every gear, does it do it in neutral or only when moving?

If it’s only when moving is it under load (I.e. engine accelerating or engine keeping a constant speed) and does it squeak under no load or deaccelerating?

The rare quick belt squeal on start-up is different then the 2100 RPM high-pitch squeak. This noise sounds very much like a belt, or even very very early signs of a power steering pump going bad. And the sound is coming from the front of the vehicle. Like on a start-up on a cold and frosty morning and gives a quick belt chirp as soon as the engine starts-up, then goes away immediately.

2100rpm squeak is in every gear (though very minimal or sometimes does not make the noise in 1st gear at all). It does not make the noise when stationary and I rev the engine up to 2100 rpms, whether in gear with the clutch pressed or out of gear in neutral. Only when moving and in gear.

It will happen on acceleration & deceleration, or when cruising at a constant speed whenever it's in the 2100-2200 rpm range. It happens when under load (going up a hill) or no load when cruising on flat road, or when going downhill. When the high-pitch squeak happens at 2100rpm and I push in the clutch the noise goes away instantly, in any gear, in all situations.

Took two quick videos of the belt crank pulley and belts, they seem to be without play. 

youtube.com/shorts/3_2jJUYGIKI?feature=share

youtube.com/shorts/KybipfGMCpo?feature=share



Where as this video (this is not my Jimny) looks very noticeably wobbly - 

PDX-ORE wrote:

 
It will happen on acceleration & deceleration, or when cruising at a constant speed whenever it's in the 2100-2200 rpm range. It happens when under load (going up a hill) or no load when cruising on flat road, or when going downhill.

 

In the first post, you said the noise only happened under load.  Has the pattern now changed, or is there a typo here?
 

Have you run the car with all the wheels in the air, obviously correctly and safely positioned on axle stands and conducted with safety in mind. That will allow you to carefully use a stethoscope to directly assess all the components that are rotating. Just be mindful when you do this that what you are doing is going to try and kill you if you don't pay attention.