Bodsy
Site Sponsor
Member Since: 06 Nov 2006
Location: In the Clubhouse
Posts: 21361
  
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DN, the newer design for the EUiv engines will replace all the EUiv engine oil pumps. Not sure about the EUIII pump.
dom, yes, fuel filter seems OK and fully working EGR's  Bodsys Brake Bible
D4/D3 Remote FBH heat kits
BAS Remaps/ EGR Blank
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 11th Jun 2012 1:18 pm |
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DN
D3 Decade
Member Since: 23 Jun 2006
Location: W.London.
Posts: 2344
 
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Thanks Bodsy ......:Anyone know about Euro III ?
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| 11th Jun 2012 1:21 pm |
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countrywide
Member Since: 16 Sep 2007
Location: UK
Posts: 6019
 
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The thing is the casting is breaking off, so it would be almost instantly detached, it wouldn't tear like the steel would and slowly let go. So the bit that confuses me is that the tensioner wheel is totally burned away from not being able to turn. Am I wrong in thinking that this can only happen if there is tension holding it to the belt, so it must have happened before the casting let go otherwise you wouldn't get sufficient friction to cause that wear.
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| 11th Jun 2012 1:27 pm |
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stapldm
Member Since: 11 Sep 2006
Location: Swine Town
Posts: 2330
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Could the wheel have dropped and wedged between the plastic shield and the belt and therefore both been melted by the passing belt and helped keep it tight on the crank pulley at the same time? Dr. Ian Malcolm:
"Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should."
Transgenic tomato anyone?
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| 11th Jun 2012 6:41 pm |
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countrywide
Member Since: 16 Sep 2007
Location: UK
Posts: 6019
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The belt would have jumped off when the tensioner let go.
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| 11th Jun 2012 6:52 pm |
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buda
Member Since: 24 Jan 2010
Location: strathclyde
Posts: 334
 
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You can see all breaks occur at the weakest point (thinnest part of casting). Being a casting (rather than a forging) it wont have much tensile strength and I would think any excess force by Torquing up the tensioner bolt too much could cause the start of a weakening--hairline crack or the likes. Then after running the engine some thousands of miles the vibration would then be enough to cause the casting to break away..........
May even not need to torque up too much, just by the action of removing and reinstalling could potentially cause a weakness....
Wonder why they cast it with all those cavities which appear unecassary, except to lose a bit of weight.
Anyway thats my theory. 
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| 11th Jun 2012 6:57 pm |
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DaveT
Member Since: 01 Aug 2005
Location: Cornwall
Posts: 2576
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Could the tensioner pulley wheel (bearing) be siezing?
Do the failed ones still turn freely?
The bit I don't get is that none happen for 7 yrs & then all of a sudden along come 15 or so. What's changed? Long succession of Disco's since 2001...
SIII Lightweight - neglected & rusting. Bulkhead, A panels, vent panel & outriggers now disintegrated - Next years project!
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| 11th Jun 2012 7:04 pm |
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DN
D3 Decade
Member Since: 23 Jun 2006
Location: W.London.
Posts: 2344
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I agree with buda's theory . I was taught in my apprenticeship  (aircraft engineering), that cast alloy components, (like the exposed lug that forms this mounting), would need supporting /reacting against when torqueing or undoing. Just the mere torqueing and undoing here (and I know he torque is not high),could easily set up the necessary stresses to lead to fracture sooner or later. Still puzzled about the ones that have failed before being disturbed in this way though 
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| 11th Jun 2012 7:19 pm |
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Russell
Member Since: 23 Aug 2007
Location: Kent
Posts: 10564
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As I said earlier has anyone contacted LR and asked them? If there are this many failing and all on the same lines then there may well be an issue and the expertise offered by LR could be of help. MY17 D5 1st Edition Namib Orange
MY15 D4 HSE Kaikoura Stone
MY12 D4 HSE Nara Bronze Sold and gone
MY11 D4 HSE Stornaway Grey Sold and gone
D3 S spec Silver Sold and gone
Tow bar, full length roof bars, side steps, tow bar storage unit, surround camers.
D4 camera club
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| 11th Jun 2012 7:20 pm |
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stapldm
Member Since: 11 Sep 2006
Location: Swine Town
Posts: 2330
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The ones that have not yet been molested have been under constant torque from the tensioner spring for the last 5+ years... Dr. Ian Malcolm:
"Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should."
Transgenic tomato anyone?
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| 11th Jun 2012 7:21 pm |
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buda
Member Since: 24 Jan 2010
Location: strathclyde
Posts: 334
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Once the tensioner bolt is torqued up, there should be vitually no further torsional force applied to the bolt except perhaps the small spring (negligible)force that pushes the tensioner wheel out eccentrically towards the cambelt. Since the tensioner wheel rotates as its on a bearing, it should exert no more torsional force on the screw/casting.
With engine running there would be some sideways (bending moment) force on the screw/casting from the belt but would be damped by the spring force on the tensioner spring. This sideways force/vibration is what I think would cause an aleady stressed casting to break.
The increased rate of failure is probably due to the increase in cambets being done.
Bottom line is the casting is not up to the job as its not robust enough to withstand the stresses induced during a tensioner /belt change
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| 11th Jun 2012 8:19 pm |
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DSL
Keeper of the wheelie bin
Member Since: 11 May 2006
Location: Off again! :-)
Posts: 73071
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Would be interesting what would be found if someone were to get an expert report done. Time for a whip-round?
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| 11th Jun 2012 8:34 pm |
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Bodsy
Site Sponsor
Member Since: 06 Nov 2006
Location: In the Clubhouse
Posts: 21361
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It's an option I'm considering if people want to contribute  Bodsys Brake Bible
D4/D3 Remote FBH heat kits
BAS Remaps/ EGR Blank
Transmission Flush
Software updates/enabling
Clock/ SNOTM /3Flash / 4x4Info /BT Update /Service Reset/Error Codes / Gearbox Reset
See It Here
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| 11th Jun 2012 10:01 pm |
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Gareth
Site Moderator
Member Since: 07 Dec 2004
Location: Bramhall
Posts: 26770
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Iain, when yours broke, did the engine seize instantly, or did it just stop delivering power and slow down?
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| 11th Jun 2012 10:06 pm |
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stapldm
Member Since: 11 Sep 2006
Location: Swine Town
Posts: 2330
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buda wrote:...except perhaps the small spring (negligible)force that pushes the tensioner wheel out eccentrically towards the cambelt...
I thought that the spring was actually quite powerful and would therefore keep a constant torque on the cast mounting (not the bolt once tightened). Dr. Ian Malcolm:
"Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should."
Transgenic tomato anyone?
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| 11th Jun 2012 10:13 pm |
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