Another chuffing noise

Another chuffing noise

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Discussion

adam quantrill

Original Poster:

11,538 posts

242 months

Wednesday 22nd November 2017
quotequote all
Except this one doesn't "chuff", but it's chuffing annoying.

This one is like a whirring noise that starts at about 20mph and whirs according to road speed.

Knocking it out of gear so the engine is idle doesn't change the noise (except it gets slower again).

If I put my hand on the parcel shelf I can feel a related vibration, but equally I can feel it a bit through the steering wheel.

I have tried the following - replaced both front wheel bearings (they seemed fine anyway). Jacked up the rear of the car and then supported the hubs to stress the driveshafts. Then stuck it in 5th on fast idle (=30mph) and listened underneath. Couldn't really hear anything definite.

I have checked fluid levels in diff and gearbox - all OK.

The car went through the MoT with the noise and I got no advisories about noisy wheel bearings, besides the rears seem OK when rotated by hand.

Apart from the noise it drives fine, the noise doesn't vary around corners etc.

Any ideas?

I am thinking of rigging up a clip-on microphone so I can listen to various parts while driving.

TwinKam

2,974 posts

95 months

Wednesday 22nd November 2017
quotequote all
Tyres.
Run your hands around the tread and I'll bet you'll find that they're no longer truly round, the blocks forming facets. This gives a road-speed related thrumming very similar to a noisy wheel bearing.

adam quantrill

Original Poster:

11,538 posts

242 months

Wednesday 22nd November 2017
quotequote all
Hmm I think I'll try inflating them another 10psi, do a quick run, and see if it alters, in that case. Cheap, quick, and worth a try.

ElvisWedgeman

2,714 posts

165 months

Wednesday 22nd November 2017
quotequote all
Speedometer or the cable or both?

Tony. TCB.

adam quantrill

Original Poster:

11,538 posts

242 months

Wednesday 22nd November 2017
quotequote all
Maybe but it would have to travel down the propshaft to be felt in the parcel shelf, and the speedo works well, no jumping.

madformotors

125 posts

82 months

Thursday 23rd November 2017
quotequote all
adam quantrill said:
Hmm I think I'll try inflating them another 10psi, do a quick run, and see if it alters, in that case. Cheap, quick, and worth a try.
Hi,
Although my 'chuffing' noise hasn't completely gone, it was the tyre change that reduced it. If the increase in pressure doesn't identify the source, and you can't feel anything wrong with the tyres , how about trying your spare on all 4 corners in turn to see if that makes a difference?Ian

rev-erend

21,409 posts

284 months

Thursday 23rd November 2017
quotequote all
Get rid of the Super Charger .. that should sort it.

biggrin

adam quantrill

Original Poster:

11,538 posts

242 months

Thursday 23rd November 2017
quotequote all
EH, WHATTT???

yeah the spare is a space saver so that would definitely make a difference! If it's a tyre.

RCK974X

2,521 posts

149 months

Thursday 23rd November 2017
quotequote all
Similar idea but sounds stupid - swap the tyres around.

Your not supposed to swop sides with tyres, as they *do* wear in line with which way they rotate, and they can cause drift/pull/noise issues over time.
(but it's a PITA to swop them all around...)

I had weird squeal noises and a pull to one side (not in wedge) and spent money having the alignment done, was exactly the same. Swopped tyres front to rear
on each side after suggestion from mechanic who did the job ("I know it sounds weird, but....), and the problem magically disappeared....

So if you can't find anything else.....it's possible....

adam quantrill

Original Poster:

11,538 posts

242 months

Friday 24th November 2017
quotequote all
Rears are 245 front are 225, but I could put some spare 225's on the rear I spose.

TwinKam

2,974 posts

95 months

Friday 24th November 2017
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If it is the tyres out of shape, you will feel it with just your hands, believe me.

mrzigazaga

18,555 posts

165 months

Friday 24th November 2017
quotequote all
Hi Adam

Could be a number of things.....Sticky rear caliper..handbrake pads touching...is there ANY play in the rear wheel..other than the bush compliance?



Ziga

KKson

3,403 posts

125 months

Saturday 25th November 2017
quotequote all
Bearing, knackered tyre, knackered UJ, catching brake caliper, lump of crap trapped between disc and caliper. Doubt if it's major diff or gearbox issue, but you never know.

adam quantrill

Original Poster:

11,538 posts

242 months

Sunday 26th November 2017
quotequote all
Bear in mind that the car went through the MoT with this noise so the bearings must be OK. Brakes and UJ's too.

Today I stuck in 25psi all round and the noise seemed to get less, so maybe it's tyres, I'll try reducing and see if it comes back stronger.

The odd think is that the tyres are well used and the noise has only just appeared, so I have been reluctant to blame them, but maybe it's the tyres, more investigation needed.

adam quantrill

Original Poster:

11,538 posts

242 months

Monday 27th November 2017
quotequote all
The noise does seem a bit different with the tyres pumped up, more of a turbine-like whirring.

Will try less pressure soon.

mrzigazaga

18,555 posts

165 months

Monday 27th November 2017
quotequote all
adam quantrill said:
The odd think is that the tyres are well used and the noise has only just appeared.
Perhaps its the "Zero degree belt"....In other words..."Bald tyres".....hehe

adam quantrill

Original Poster:

11,538 posts

242 months

Monday 27th November 2017
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Ha ha - not THAT well worn, Zigmeister...

adam quantrill

Original Poster:

11,538 posts

242 months

Thursday 4th January 2018
quotequote all
Just changed the diff oil, which was a bit low, by about half a litre, and quite black+silver.

Also noticed the filler plug had some score marks on it, maybe due to being tightened into the hole too much.

As it's a tapered thread I bunged on 3 turns of PTFE take to make it seal with less screwing in.

Anyhow all back together and a test drive and the noise persists.....

Maybe a tyre/wheel swap next...

rev-erend

21,409 posts

284 months

Thursday 4th January 2018
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Maybe you have changes the prop position at some point.

Could be the prop has a slight vibration or imbalance.

DCerebrate

341 posts

110 months

Thursday 4th January 2018
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Failing / worn diff seems most likely.