Deep rumbling sound from car... - Page 3

BigAde · 14th February 2017, 19:02

Hi everyone

Appreciate all the answers/comments so far... was feeling a bit under the weather last night... so have only just been able to go out and do some experimenting.

So today's test drive did show that the noise didn't vary when swerving/cornering from side to side. I also jacked up each corner and was able to spin each wheel freely and without noise. There was also no front-back play (not sure if that's the right term) in each wheel. I'm tentatively ruling out bearings based on that.

I then took each wheel off and checked for sticking pads/ anything out of the ordinary etc - nothing that seemed obvious to me... but then I'm not hugely experienced.

I then switched the two older tyres over for the summer wheels. No change.

Then I noticed it behind the nearside rear wheel... a gaping hole in the front of the back box... Photo below.

Looks like time to replace that back box. Still say it doesn't sound like traditional exhaust leakage... think some sort of resonance is playing a factor...

klarzy · 14th February 2017, 19:17

Quote:

Originally Posted by BigAde

Hi everyone

Appreciate all the answers/comments so far... was feeling a bit under the weather last night... so have only just been able to go out and do some experimenting.

So today's test drive did show that the noise didn't vary when swerving/cornering from side to side. I also jacked up each corner and was able to spin each wheel freely and without noise. There was also no front-back play (not sure if that's the right term) in each wheel. I'm tentatively ruling out bearings based on that.

I then took each wheel off and checked for sticking pads/ anything out of the ordinary etc - nothing that seemed obvious to me... but then I'm not hugely experienced.

I then switched the two older tyres over for the summer wheels. No change.

Then I noticed it behind the nearside rear wheel... a gaping hole in the front of the back box... Photo below.

Looks like time to replace that back box. Still say it doesn't sound like traditional exhaust leakage... think some sort of resonance is playing a factor...

Check those inner CV joints...

bonny · 14th February 2017, 19:18

Glad you found the culprit. Although it's going to cost you money it's always satisfying when you find what the problem was. What will you do now, go for a stainless back box?

rovertone · 14th February 2017, 20:11

Quote:

Originally Posted by BigAde

Hi everyone

Appreciate all the answers/comments so far... was feeling a bit under the weather last night... so have only just been able to go out and do some experimenting.

So today's test drive did show that the noise didn't vary when swerving/cornering from side to side. I also jacked up each corner and was able to spin each wheel freely and without noise. There was also no front-back play (not sure if that's the right term) in each wheel. I'm tentatively ruling out bearings based on that.

I then took each wheel off and checked for sticking pads/ anything out of the ordinary etc - nothing that seemed obvious to me... but then I'm not hugely experienced.

I then switched the two older tyres over for the summer wheels. No change.

Then I noticed it behind the nearside rear wheel... a gaping hole in the front of the back box... Photo below.

Looks like time to replace that back box. Still say it doesn't sound like traditional exhaust leakage... think some sort of resonance is playing a factor...

Don't necessarily give up on the exhaust. Is it box still strongly attached to the pipe, I found a hole like that two years ago it wasn't blowing that much so I repaired it with Gun Gun paste, followed the instructions carefully warmed the exhaust, moistened it etc and it's still going strong.

BigAde · 14th February 2017, 20:13

Quote:

Originally Posted by bonny

Glad you found the culprit. Although it's going to cost you money it's always satisfying when you find what the problem was. What will you do now, go for a stainless back box?

Probably... having read reports of how poor all the aftermarket exhausts are. Seems pricey mind.

BigAde · 14th February 2017, 20:22

Quote:

Originally Posted by rovertone

Don't necessarily give up on the exhaust. Is it box still strongly attached to the pipe, I found a hole like that two years ago it wasn't blowing that much so I repaired it with Gun Gun paste, followed the instructions carefully warmed the exhaust, moistened it etc and it's still going strong.

Still seems to be strongly attached, yes. I might give that a shot then... can't surely do any harm trying for a £3 tub of paste.

Dragrad · 14th February 2017, 23:44

Thread moved to a more appropriate forum. Re-direct left in old. This may be the better forum as threads get ‘lost’ very quickly in the General Forum.

BigAde · 2nd March 2017, 16:36

So... just updating this thread. After a 2 week wait for them to fit me in I've now got a new stainless steel back box fitted from Longlife. Very friendly bunch, they did manage to damage some heat-shielding further back so that it was hanging low on the car. Fortunately my wife was driving behind me and flashed me to pull over. So I went back to them and they fixed it straight away.

Anyway, the noise has... changed. It's now clear to me that I was hearing two noises combined. One was the exhaust. The other I'm now almost convinced is wheel bearing because the noise now stops when going round a sharp right hand bend (this didn't happen 2 weeks ago).

So the question now is whether it's front offside or rear offside.
Any clever ways of determining that?

RPWC · 2nd March 2017, 16:47

If it disappears when turning right, it's front offside, as whennturning right ,the weight is lifted off it slightly

BigAde · 2nd March 2017, 16:58

Quote:

Originally Posted by RPWC

If it disappears when turning right, it's front offside, as whennturning right ,the weight is lifted off it slightly

Ok right, thanks, that's good to know.

I was thinking that maybe if I ordered from Matt at DMGRS both front and rear bearings then book it in to my mechanic to have front done and then get them to road test afterwards and change the rear if they need to. At least then he'll have the parts and I don't have to wait for more parts.

Then, if I've no need of the rear one, I can sell it on on the forums perhaps.

14th February 2017, 23:44	#27
Dragrad This is my second home *None DROWNED** Join Date: Aug 2007 Location: Cardigan Posts: 33,339 Thanks: 1,257 Thanked 1,664 Times in 1,081 Posts	Thread moved to a more appropriate forum. Re-direct left in old. This may be the better forum as threads get ‘lost’ very quickly in the General Forum. __________________ Andrew Ich Dien Problem solving is... lateral thinking SEARCH FIRST ...ASK LATER...

2nd March 2017, 16:47	#29
RPWC This is my second home 75 model car Join Date: Apr 2011 Location: Newcastle upon Tyne Posts: 20,177 Thanks: 4,008 Thanked 5,083 Times in 3,114 Posts	If it disappears when turning right, it's front offside, as whennturning right ,the weight is lifted off it slightly __________________ Cheers. Rich…

14th February 2017, 19:18	#23
bonny Regular poster ZT-T Join Date: Mar 2013 Location: Surrey Posts: 87 Thanks: 20 Thanked 37 Times in 26 Posts	Glad you found the culprit. Although it's going to cost you money it's always satisfying when you find what the problem was. What will you do now, go for a stainless back box?

2nd March 2017, 16:36	#28
BigAde Posted a thing or two MG ZT-T+ 135 CDTi Join Date: Oct 2012 Location: Sussex Posts: 1,502 Thanks: 511 Thanked 224 Times in 178 Posts	So... just updating this thread. After a 2 week wait for them to fit me in I've now got a new stainless steel back box fitted from Longlife. Very friendly bunch, they did manage to damage some heat-shielding further back so that it was hanging low on the car. Fortunately my wife was driving behind me and flashed me to pull over. So I went back to them and they fixed it straight away. Anyway, the noise has... changed. It's now clear to me that I was hearing two noises combined. One was the exhaust. The other I'm now almost convinced is wheel bearing because the noise now stops when going round a sharp right hand bend (this didn't happen 2 weeks ago). So the question now is whether it's front offside or rear offside. Any clever ways of determining that?