Flapper
Member Since: 04 Feb 2015
Location: Gloucester
Posts: 341
  
|
Front wheel bearing. When they go it sounds horrible.
Does the noise stop when you put on the brakes.
|
 6th Nov 2022 9:22 am |
|
|
Jagbusa
Member Since: 02 Nov 2022
Location: Costa del Blackpool
Posts: 37
|
loanrangie wrote:If it doesn't lodge an error code its likely a mechanical problem that doesn't have an associated sensor or flow on to an electrical item.
I am almost definite it is a mechanical problem I just wondered if a failing injector would create the noise but not produce a fault code.
Flapper, the noise is linked to engine revs not wheel speed, so isn't a wheel bearing but thanks for the suggestion.
I think I mentioned before, once up to speed and that is any speed, driving on the lightest throttle there is no noise, well no perceptible noise. As you increase pressure on the throttle, so putting the engine under load, the noise gets louder matching the revs. Ease off the gas and the noise diminishes, ease back on and it comes back. The noise is only there under acceleration, not when revved and I would say it is only 1 cylinder making the noise. Other than this noise everything else seems smooth and quiet, no loss of power and off gas, no different to the other 3 disco 3's in the family. 2009my Discovery 3 2.7V6 HSE
|
| 6th Nov 2022 12:27 pm |
|
|
darrind
Member Since: 04 Jul 2008
Location: In A World of My Own!
Posts: 2863
  
|
Have you checked the Aux belt tensioner, they can make a row when the bearing is on its way out and can be checked easily by removing the Aux belt for a quick check Must stop buying shiny toys....
|
| 6th Nov 2022 12:31 pm |
|
|
Jagbusa
Member Since: 02 Nov 2022
Location: Costa del Blackpool
Posts: 37
|
Hi Darrind, as soon as we have a break in the weather I intend to check the auxilliary belts and pulleys, I would very much like it to be something as simple as that. Thanks for the suggestion.  2009my Discovery 3 2.7V6 HSE
|
| 6th Nov 2022 12:52 pm |
|
|
salmoner
Member Since: 09 May 2014
Location: Blackpool
Posts: 156
|
Flacks your best man, not far from you only in Freckleton, having said that I think he might be semi-retired now but I'm sure he'd give you some pointers 
|
| 6th Nov 2022 4:04 pm |
|
|
Jagbusa
Member Since: 02 Nov 2022
Location: Costa del Blackpool
Posts: 37
|
Thanks Salmoner.  2009my Discovery 3 2.7V6 HSE
|
| 6th Nov 2022 4:53 pm |
|
|
Flapper
Member Since: 04 Feb 2015
Location: Gloucester
Posts: 341
|
Belt tensioner fails at the spring which makes it start to lean over if they get realy bad the wheel rubs on the oil pump which makes a noise ( speed related)
Also check turbo hose on the top corner by the air box.
|
| 6th Nov 2022 8:54 pm |
|
|
Breg90
Member Since: 04 Feb 2017
Location: Falkirk
Posts: 352
|
Is is a main bearing of big end bearing. Believe that as big end bearings fail the piston can kiss the head. Might explain the 'not sure where the sound is from' statement.
I'd remove the oil filter and check for debris. Series one 1949 - in bits, chassis is strapped to the ceiling in my garage (beside the canoe)
LR 90 - In bits
Disco 3 - currently in bits
|
| 6th Nov 2022 9:01 pm |
|
|
Jagbusa
Member Since: 02 Nov 2022
Location: Costa del Blackpool
Posts: 37
|
Thanks Flapper and Breg90, points noted. As soon as I have reasonable weather I will be dropping the oil and filter and checking belts and tensioners.
Breg90, the tolerances must be really close for the piston to touch the head if a big end in is on the way out, or it must be so fooked it has the option of bashing its head in or sticking a leg out lol
Anyways thank you everyone so far for your thoughts and ideas, very much appreciated. 2009my Discovery 3 2.7V6 HSE
|
| 6th Nov 2022 9:20 pm |
|
|
motorworks
Member Since: 14 Nov 2019
Location: Usk
Posts: 412
|
At 186k miles the cam chains and tensioners will be well worn if they have not been replaced. Wear on the hydraulic tappets creates a rattling sound. Noise from these components would be most apparent at cold startup, but not necessarily loud or alarming.
There is a point at which a seemingly healthy engine will suddenly fail from a snapped cam chain. I bought a D3 (see other thread) with suspected broken crankshaft, but timing belt tensioner had snapped, because broken chain had locked the o/s camshafts.
I expect there was detectable noise building up the failure, but with no loss of power or warning lights the owner may have postponed investigation to a regular service, or more convenient time.
I think this is a rare occurrence, so not much to go on in terms of prior symptoms.
How does this fit with tapping/knocking noise on l under load? Well, stationery revving the engine requires minimal fuel delivery - but acceleration under load demands high fuel delivery from HPFP so maximum load on the n/s cam chain allowing the slack side movement to vibrate against the worn guides. At some point the velocity of chain travel creates enough tension to take up the slack and the noise subsides.
Based on this assessment, I would advise you to stop using the car ASAP. To check the chains, the intake covers need to be removed, replacing the chains is a difficult job. Chris
|
| 6th Nov 2022 10:28 pm |
|
|
Jagbusa
Member Since: 02 Nov 2022
Location: Costa del Blackpool
Posts: 37
|
Ok, update for all you Disco 3 wizards, Oil and Filter change with Castrol Magnatec C3 5W40, halved the time taken for the oil light to go out, approx 1 .5 seconds as opposed to 3. There was no metal in the oil or filter, it was very clean, well for diesel oil anyway.
Have checked auxiliary pulleys and devices, all within spec except for the water pump. This had a lot of play but have been told this is common. There are no leaks on the pump so maybe there is quite a lot of play designed into them anyway, I am sure someone will advise.
The noise is still there although a degree quieter and at one point gone altogether as I came off a roundabout onto a slip road and floored it, I was at a fair chat at this point and as the revs rose, I did think "The noise has gone", which it had momentarily, but came back as I slowed. Which made me wonder at first a weak or sticking follower, but then linked the possible oil surge from going right round the roundabout to hard left down the slip road and a noisy TC as mentioned in an earlier post.
As the oil contained no particles, I am happy at this point it isn't a bearing or any other metal to metal contact, but do wonder if it is low oil pressure, so I am going to fit a new OEM oil pump and see if that makes a difference. I am also going to change the gear box oil even though a new TC was fitted 50k ago. I will also change the water pump when I do the oil pump.
Please feel free to give me your 10 penneth.
Thanks
Steve 2009my Discovery 3 2.7V6 HSE
|
| 13th Nov 2022 10:12 pm |
|
|
motorworks
Member Since: 14 Nov 2019
Location: Usk
Posts: 412
|
Do you know how many miles since the previous oil change? Chris
|
| 13th Nov 2022 10:53 pm |
|
|
Breg90
Member Since: 04 Feb 2017
Location: Falkirk
Posts: 352
|
How did you check the old filter?
You should be cutting the top/bottom off, then cutting down the length on one side. Then pull the paper out from a concertina to a flat sheet of paper - should now be a rectangle. Look for shiny specs on the outside surface. If you see more than the odd one you have an issue. Series one 1949 - in bits, chassis is strapped to the ceiling in my garage (beside the canoe)
LR 90 - In bits
Disco 3 - currently in bits
|
| 13th Nov 2022 10:57 pm |
|
|
Jagbusa
Member Since: 02 Nov 2022
Location: Costa del Blackpool
Posts: 37
|
motorworks wrote:Do you know how many miles since the previous oil change?
It had been serviced just before I bought it so maybe 1500 miles max.
Breg90 - I separated each fold of the filter all the way round and also checked in the bottom of the oil drain pan. 2009my Discovery 3 2.7V6 HSE
|
| 13th Nov 2022 11:34 pm |
|
|
motorworks
Member Since: 14 Nov 2019
Location: Usk
Posts: 412
|
I wonder if the last oil change was prompted by unusual noise, in which case filter check now would not reveal much. If the sump is clean inside and not recently removed that is a good sign. I would also look at the oil pickup filter, that collects debris and can easily be restricted. Chris
|
| 13th Nov 2022 11:49 pm |
|
|
