Suzuki Forums banner

1 - 12 of 12 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
Any ideas what the following could be caused by?:
- Only happens after driving for about 30 minutes, sometimes less. i.e. Probably heat/expansion related.
- Starts like a soft mouth whistle but builds up into a boiling kettle type whistle
- Seems to be related to braking as it kicks in earlier when driving hills with more braking.
- Modulates with acceleration and braking. Also turning corners at speed (without braking) can modulate the sound. Tends to lessen or or temporarily clear when accelerating.
- Happens at high speed and low speed. From 100km/hr down to just before stopping at lights.
- Repeatable. Happens 100% of the time once it has started (warmed up enough).

So far the dealer has:
Checked the wheels and brakes for wear or obstacles (Stones/sticks etc). Nothing found.
Replaced belts. = No change
Replaced brake pads and discs. = No change

What could it be? Brake calipers? I'm a bike rider and imagine something like the brake closing then not retracting fully for some reason (heat related)...
My dealer is stumped and I am out of pocket $$$.

Hoping there is an experienced mechanic out there. Cheers
 

·
Registered
Joined
·
5,577 Posts
only when in motion and does it change with revs?

The fact they mechanic has fired the parts cannon and checked belts and brakes suggests he hasn't diagnosed it properly, or is too lazy to actually work out where the noise is coming from.

More symptoms please, I know you say lessens under acceleration, but deceleration louder or softer? what about steady revs? whistling at idle? does it do it coasting with engine off?

reason I ask is that if you shut the engine off and it stops making the noise then drive train and brakes are not the cause.

checked the sprung loaded exhaust connection ? they are known to leak and whistle.

checked master cylinder vacuum line? (and all the other lines?) Splits in these can certainly cause whistles but usually have rough running associated with them.

hard to tell from what you describe, maybe a video would help.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #3
Thanks for the reply. To answer the questions and add more detail:

1. Yes, the squeal is only when in motion. Connected to motion rather than revs.

2. The noise seems to increase under deceleration but I am conscious that the background revs noise decrease in this situation so it may just appear to be louder. Likewise, my impression that it decreases under acceleration could possibly be caused by increased rev noise and the fact that the part may have cooled at the lights... Whistles beautifully at steady revs (at speed), doesn't whistle at idle. Haven't tested coasting with the engine off - good thought.

3. The sprung loaded exhaust connection has not been checked as far as I know. Does it fit the symptoms?

4. The master cylinder vacuum line (and all the other lines) have not been checked as far as I know. Again, do these fit the symptoms? No rough running, the car runs sweet apart from the noise.

?????????
 

·
Registered
Joined
·
134 Posts
Where does the squeel sound like it is coming from? In front (engine area), underneath you, or to your rear? Maybe left or right side?
 

·
Registered
Joined
·
5 Posts
Discussion Starter #6
Well, it sounds like it is coming from the left side and the dealer identified it as the left front wheel prior to changing the brake pads and discs. But, I am not convinced that it was accurately identified because noise bounces around a car.
The ChassisEar suggested by aquanaut20 seems to be something that would have been useful if it had been used.
I'm about to take it back to the dealer and will mention both ChassisEar and exhaust back pressure as suggestions.
I'm going o/s for a week so the car will be left with them to fix. I'll report back.
Thanks for the suggestions
 

·
Registered
Joined
·
134 Posts
You confirmed it's coming from the front of the car, engine area, front wheels, etc., as opposed to say a rear wheel bearing or something. Is it by chance related to the steering, rather than the symptoms you reported? As others have said, important to try and isolate the squeal and diagnose the problem before a mechanic throws more parts at it. For a few silly suggestions, check that you have good clearance with the radiator fan to the plastic cowling, accessory belts are properly tight, power steering fluid OK, or for a crack or small hole in your exhaust header/down pipe, oil in the front differential, etc. Hard to be too helpful without hearing the squeal ourselves.
 

·
Registered
Joined
·
8,801 Posts
Well, it sounds like it is coming from the left side and the dealer identified it as the left front wheel prior to changing the brake pads and discs. But, I am not convinced that it was accurately identified because noise bounces around a car.
The ChassisEar suggested by aquanaut20 seems to be something that would have been useful if it had been used.
I'm about to take it back to the dealer and will mention both ChassisEar and exhaust back pressure as suggestions.
I'm going o/s for a week so the car will be left with them to fix. I'll report back.
Thanks for the suggestions
I hope the dealer is honest and not dinging you for improper diag an unnecessary parts.. :eek:

I have a policy, IF and I mean if, I ever install a part that did not rectify the issue, I will eat it... Had to do it once, 15yrs ago.. My boobo.!

Never install part unless it is proven to be at fault....
 

·
Registered
Joined
·
5 Posts
Discussion Starter #9
Thanks aquanaut20, I agree and was unhappy at the wholesale parts replacement without identification of the problem, compounded by the problem not being fixed. I dropped the vehicle back in yesterday and they refunded me for the parts (discs and pads) and apologised profusely which is a good sign.
I took their head Suzuki tech guy for a drive to analyse the squeal and he concluded:
- Replacing the pads and discs had made 0% difference
- He is now not sure it is coming from the front left wheel (!). I mentioned the ChassisEar and he agreed but I suspect he doesn't have access to one.
- We tried revving the engine while stationary and couldn't get any squeal at all.
- He didn't think it was anything to do with exhaust back pressure.

Anyway, they have the car and I am away for a week so hopefully all will be revealed by the time I return. Thanks again for the suggestions.
 

·
Super Moderator
Joined
·
23,877 Posts
If no chassis ear, maybe have a passenger do a recording for you and upload it. It may also be helpful if we knew what you were driving.....???
 

·
Registered
Joined
·
5 Posts
Discussion Starter #11
The dealer just contacted me, as per below:

A update on your vehicle is, we have reproduced the noise while driving the vehicle on the hoist.

It took some time but we got there. We have found the issue to be coming from the driveline of the vehicle, and not any braking components.

It would get a almighty noise coming from the tail shaft slip joint as soon as there was some real heat transferred through it. A new tail shaft is on order.

Thanks for peoples suggestions, it was indeed an unusual problem.
I wonder what would cause a tail shaft to fail? Towing? Rough ground?
 

·
Registered
Joined
·
5,577 Posts
The dealer just contacted me, as per below:

A update on your vehicle is, we have reproduced the noise while driving the vehicle on the hoist.

It took some time but we got there. We have found the issue to be coming from the driveline of the vehicle, and not any braking components.

It would get a almighty noise coming from the tail shaft slip joint as soon as there was some real heat transferred through it. A new tail shaft is on order.

Thanks for peoples suggestions, it was indeed an unusual problem.
I wonder what would cause a tail shaft to fail? Towing? Rough ground?
universal joints fail....
 
1 - 12 of 12 Posts
Top