Technical Weird rolling noise - defeated garage!

[Brim987]

Hi All,

I have a 2001 1.2 Brava with a curious problem.

Its got a noise that's driving me mad and has just defeated 3 mechanics at my local garage.

So, at about 15mph turn off the engine and let it roll in neutral.. there's a speed related low rumbling noise. They checked all the wheel bearings, all ok apparently and they couldn't see anything catching anywhere.

So the noise is there right down to 1 mph.
I will now try to describe the 15mph to 1mph noise... (yikes).

Grrr Grrr Grrr Grrr Grrr Grrr Grrr Grrr Grrr Grr Gr stop. (That was supposed to show a decreasing frequency of occurrence).

I just don't know what it could be if not a bearing.

Any ideas appreciated....

Thanks
Steve

 

[varesecrazy]

Ancient ..or repaired tyre?

Have they spun the wheels off the ground.. or just driven it ?

 

[Brim987]

Firstly, apologies for the delay in replying.

I've attached a recording of roiling in neutral, engine off from about 10mph to zero. It makes no difference with clutch in or out.
In the last few seconds you can hear it slow right down like a catching wheel.
In reality it's a bit higher pitched than the phone recording sounds.
When driving it sounds like the right front, the passenger thinks it's the left front.

RE: Ancient ..or repaired tyre?
I don't know tyre age, but there is some perishing. The mechanic mentioned
that being a possibility, at least until I took him out in it and he know thinks it's the gearbox. I was surprised since it does it in neutral but he explained it's still spinning.

>Have they spun the wheels off the ground.. or just driven it ?
It's going on a ramp in about 10 days since the mechanic wants to put some gearbox additive in it to see of it quietens down, but so far just driven.

I freely admit I'm no mechanic but I struggle to buy the tyre noise, and even the gearbox idea sounds strange too (clue being that clutch disengaged doesn't stop noise).

My uneducated guess would have been a really bad wheel bearing or a failing universal joint on a driveshaft....????

I'd really appreciate some ideas of what to investigate...

Thanks
Steve

 

[bluejohn125]

Tricky one, I can't get anything from the sound recording.

All the suggestions make sense, apart from the gearbox additive maybe. More useful to change the transmission oil I'd say. You'd detect any worn metal shavings in what comes out.

I changed a wheel bearing on my 1.2 a few years ago so they do go, I think I detected a bit of a rumble and more or less confirmed it by rotating the wheel. I had hit a kerb previously so maybe that provoked the failure but it was high mileage.

Out-of round wheels / tyres can give odd noises and vibrations even if they are balanced, so I'd look at swapping wheels around and changing dodgy tyres.

Check brakes for binding calipers, warped discs etc.

 

[Neverth]

First thing on brava: fold the rear seats, wrap ~4-6 layers of duct tape around the metal rod where the rear seats latch, seat up and go for a drive.

They are loose and make weird noise, I also though I had suspension issues. Cheap and fast to do even if it is not the issue,

 

[Brim987]

wow, that's a good one.

 

[Brim987]

Ok thanks, I can't jack it on my drive since it's too steep to be safe but I'll get the mechanic to check the wheels before changing/adding anything else.

It still feels like a driveshaft/transmission area issue to me, we'll see.
They said the wheel bearings were ok last time in.

It happens engine off, in neutral, clutch in or out - it's some kind of rolling issue, very related to speed/ I'd say the frequency was a wheel revolution (ish).

I don't know exactly what's turning in those circumstances, bits of gearbox?, all the transmission I guess.

This is just one of those things to drive the owner mad. It sounds like an unhappy noise to me, not one to ignore...

I forgot to say it's done 61K (which looks about right based on condition...).

Steve

 

[Brim987]

Holding a screwdriver on it indicates it's right front wheel bearing, so no biggie.

(Disappointing after the garage said it was ok...)

Steve