10forcash
Member Since: 09 Jun 2005
Location: Ubique
Posts: 16534
  
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| New TSB's - rough idle & hesitation under load, TDV6 |
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Two new TSB's, both relate to possible fuel contamination / specification as root causes of premature injector wear.....
TSB LA303-019 - Discovery 3/LR3 - Rough Engine Idle After Cold Start
"A customer may report a concern that the engine idle quality is poor for 10 to 25 seconds after starting from cold for the first time during the day. No poor idle or power loss is experienced after the first initial cold start of the day and all other engine starts of the day, whether the engine is warm or hot, do not result in the same poor idle quality.
Cause: Contamination (debris/dirt or corrosion) in the fuel injectors affects injector spray and delivery rate. Contamination ingress can occur during various operations such as vehicle maintenance or repair and running on contaminated fuel. An injector with damaged internal sealing will also result in unmetered fuel entering the intake manifold.
Action: Should a customer express concern regarding the above, refer to the Diagnostic Procedure detailed in this bulletin to establish the root cause of the issue."
TSB LA303-020 - Discovery 3/LR3 - Engine Hesitation Under Load
A customer may report a concern of an engine hesitation with power reduction under high engine loads, which recovers when the amount of throttle applied is reduced (feels like an early max engine rpm governor).
Cause: The following may cause the above symptoms:
Incorrect specification fuel.
Blocked or restricted fuel filter with possible logged diagnostic trouble code (DTC) P2290 (Injector fuel pressure too low).
Crossed fuel filter pipe connections after repair or maintenance (Causes reversed flow or high back pressure).
Low fuel pump module supply pressure.
Contaminated fuel injectors.
High leak rate injectors.
Contaminated high-pressure fuel pump.
Action: Should a customer express concern regarding the above, refer to the Diagnostic Procedure detailed in this bulletin to establish the route cause of the issue.
Note that action under these TSB's may not be considered warranty work....
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 4th Sep 2006 4:08 pm |
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JMC
Member Since: 25 Feb 2006
Location: Aberdeen-Angus. Where the Bull* comes from!
Posts: 6417
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| Re: New TSB's - rough idle & hesitation under load, TDV6 |
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10forcash wrote:A customer may report a concern that the engine idle quality is poor for 10 to 25 seconds after starting from cold for the first time during the day.
Yup.... Been noticing this only in the last couple of weeks (post enhancement) 
It's only for a short time and only on the first start of the day. It's barely perceptible but it is certainly there. Interesting how this TSB comes out post enhancement and I'm only beginning to notice the symptoms post enhancement.... Conspiracy??? 
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| 4th Sep 2006 5:50 pm |
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dylansdad
Member Since: 04 Apr 2006
Location: Solihull
Posts: 745
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nope just the system reacting to the issues the enhancement has enduced.  I too have noticed this issue recently. 2004 TDV6 HSE Auto Zambezi Silver
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| 4th Sep 2006 7:05 pm |
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DG
Site Moderator
Member Since: 12 Dec 2005
Location: The Gaff
Posts: 50934
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mmmmm..... I too thought mine running a little rough on tickover at startup recently...I even bent down for a listen....put it down to a rough running brain instead  21 year LR veteran > D2 GS 2003 > D3 S 2006 > D3 HSE 2009 > D4 HSE 2013 > D4 HSE 2015 > D5 HSE 2018 > DS HSE R-Dynamic P300e 2021
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| 4th Sep 2006 7:20 pm |
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bluebarchetta
Member Since: 25 Oct 2005
Location: Aylesbury
Posts: 524
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I think i experienced the symptoms of TSB LA303-020.
I recently filled up in France at an Intermarche - I had a range of 0km and so could not put in my usual Total Excellium. I think that the Intermarche diesel may have contained some bio diesel but I had no choice.
There was certainly a loss of power under high loads + a lot of smoke 
Seems okay after a full tank of the usual, but our high tech motors do seem to be very sensitive to fuel type
(I have not had the enhancement yet or been TCed)
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| 4th Sep 2006 7:23 pm |
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Allen
Member Since: 14 Dec 2005
Location: Isle of Man
Posts: 7
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I haven't experienced the rough idle, but since having the enhancement a couple of weeks ago I'm convinced that at slow speed the engine revs don't immediately drop when I take my foot off the accelerator.
The more I think about it the more I think I may be going nuts, but it is particularly noticable when moving slowly at 1500 - 2000rpm at the speed the auto box is beginning to think about changing from 2nd to 3rd. Engine revs don't drop for two or three seconds and then the car slowly decelerates and the revs decrease slowly rather than dropping immediately to tickover.
Reading other posts I've asked my dealer to make sure that the enhancement has taken properly.
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| 5th Sep 2006 9:10 am |
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IanD
Member Since: 11 Mar 2006
Location: (Too) close to Paris
Posts: 516
 
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bluebarchetta wrote:I think that the Intermarche diesel may have contained some bio diesel ...
As far as I know, all French diesel contains 2-5% biodiesel, I think it's something to do with improving lubrication in low sulphur fuel. They just don't tell anybody.
bluebarchetta wrote:... but I had no choice.
So nobody does in France!!
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| 5th Sep 2006 2:16 pm |
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IanD
Member Since: 11 Mar 2006
Location: (Too) close to Paris
Posts: 516
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bluebarchetta wrote:our high tech motors do seem to be very sensitive to fuel type
When we collected our car, the dealer specifically said that the higher grade diesel was not necessary, since the engine was designed to be used where such luxuries (or deep wallets!) are not available.
We've always used whatever comes our way in France, with no noticeable effect. The improvement on our new (therefore "enhanced") car is significant at low revs though.
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| 5th Sep 2006 2:20 pm |
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simon
Member Since: 11 Jan 2005
Location: Shropshire
Posts: 18296
 
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well BP Ultimate definitely makes a difference.
Been using Esso Energy for a while now and just changed back 2 tank fulls so far to BP. And my range and MPG have gone up. Range by 40-60 miles and MPG up from 27 ish to 29 ish
Not a scientific test I know but very noticeable.
Also engine IS quieter and smoother than with the Esso stuff.
-s
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| 5th Sep 2006 2:24 pm |
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IanD
Member Since: 11 Mar 2006
Location: (Too) close to Paris
Posts: 516
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I think the consumption,etc. might have more to do with other additives in branded fuel in general (and perhaps ultimate diesel or whatever) as opposed to the supermarket stuff than with the biodiesel.
Fropm what you say, it looks like it could be worth looking to see whether the improvement in consumption justifieis the price difference though (which will depend on where you live). My bike tends to give improved consumption on 98 petrol than on 95, but it's not enough to justify the price difference and makes no noticeable difference to the performance (not that it needs any  )
All I was trying to say is that I don't think the engine itself is too bothered what it drinks, although our wallets might be!
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| 5th Sep 2006 3:57 pm |
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10forcash
Member Since: 09 Jun 2005
Location: Ubique
Posts: 16534
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Yep, from reading the TSB's it's clear that the problem is not the grade of the fuel, but contaminants in the fuel. Low pressure can be caused by partially blocked filters, if they are not monitored and changed, eventually particulate contaminants will be passed through and cause injector damage.
Fuel contaminated or diluted with other substances such as petrol, battery acid, cooking oil etc will not cause electro-mechanical damage (in most cases) but will cause a decrease in performance and possible instability in the engine's running
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| 5th Sep 2006 4:03 pm |
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dylansdad
Member Since: 04 Apr 2006
Location: Solihull
Posts: 745
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so where are the contaminants supposed to come from?
are they implying that maybe some vehicles have had contaminated components fitted and subsequently damage caused through use?
is it they are saying the deisel we are putting into the cars is contaminated? - this is the one that bothers me given you cannot test the quality of the fuel before using it, and the vehicle is supposed to be able to tollerate lower grade fuels than we get in this country (hence the ability to improve engine performance by reducing that tollerance)
All above are fine at the moment whilst I still have some warranty, but if the vehicle is that sensitive what can be done to ensure it doesnt continue to be an issue. (given Im having this problem since my 15K service) 2004 TDV6 HSE Auto Zambezi Silver
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| 5th Sep 2006 8:24 pm |
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10forcash
Member Since: 09 Jun 2005
Location: Ubique
Posts: 16534
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You're reading too much into it.... clearly the contaminants come from the fuel, or whatever is added to it the TSB is NOT UK only, and as such should be read in context to the relevant market.
I posted the TSB's for info, not to generate 'Disco3's can't tolerate below spec. fuel' dire warnings.
As with all manufacturers, LR have a minimum specification for the grade of fuel their engines will run on with NO PROBLEMS. Go below this level AND neglect essential maintenance, such as more frequent fuel filter changes and, if necassary, fuel tank flushing - then the symptoms listed could manifest themselves...
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| 5th Sep 2006 9:56 pm |
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dylansdad
Member Since: 04 Apr 2006
Location: Solihull
Posts: 745
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fair point and not meaning to be alarmist in any way, just trying to understand what may be causing what I and a few others have noticed.
so from that I summise my uneven idle issues and the apparent throttle limiter stopping acceleration are likely due to a more physical issue listed as opposed to contamination? 2004 TDV6 HSE Auto Zambezi Silver
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| 5th Sep 2006 10:09 pm |
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10forcash
Member Since: 09 Jun 2005
Location: Ubique
Posts: 16534
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Well as LR don't supply your fuel.....
to be fair, there are several scenario's on the full TSB's, although most relate back to fuel contaminants - it's not unknown for fuel tankers to be used for petrol one day and diesel the next, although it shouldn't happen - it does.
a few hundred litres of petrol in a 30k litre fuel tank is neither here nor there to the distributors or resellers but can mean a raised injector tip temperature by 100-150 degrees. If this happens on a motorway journey then several hours of this can effectively  your injector tips...
no fuel filter produced to date can guard against this
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| 5th Sep 2006 10:18 pm |
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