My D4 has brought up a restricted performance warning a couple of times recently. Using the iid tool to read the codes I get nothing much of significance with only a comms error with the FBH and a dodgy passenger door lock. Clearing the faults without issue and the D4 is fine for a day or two. Then its repeat the warning and clear the faults again. Today it failed to accelerate from the traffic lights,which was awkward. The only thing that springs to mind was it was while accelerating. Any ideas? Same fault codes again by the way2011 D4 HSE, it'll be nice if it ever works!
2014 D4 HSE Luxury. as if one money pit isn't enough!
My old 2005 D3. Now sold after 362000 on the original engine!
19th Sep 2023 3:14 pm
Moo D3 Decade
Member Since: 13 Aug 2010
Location: UK
Posts: 14353
Split manifold.New Defender L663 110 SE (known as Noddy!)
Sold Volvo XC90 R-Design (known as Basil)
Sold - D4 HSE (Known as Gerty)
No longer the Old Buses original owner
231,000 miles and counting
05 S manual owned from March 2005
D4 Face lifted
Still original injectors and turbo
V8 Front brakes
BAS Remap, Allisport Intercooler and deCat
EGRs blanked
T-Max split charge
Hanibal Expeedition rack
Prospeed ladder
Duratrac tyres
IID BT
BAS FBH control
The first two times was it just a warning or a warning and you experienced restricted performance?
19th Sep 2023 5:00 pm
LT
Member Since: 31 Dec 2005
Location: South West
Posts: 23803
I had a similar issue with my last D4. Turned out to be the wastegate on the second turbo was sticking. Didn't happen all the time, just occasionally under hard acceleration. Although it did get progressively worse with time.
As it was under warranty LR replaced the entire turbo system. 2006 D3 HSE (Original & still the best)-GONE
2010 D4 HSE (A bit bling)-GONE
2014 D4 HSE (Almost too bling)-GONE
2015 D4 HSE (A heated what?)-GONE
2016 D4 Landmark (Written Off)-GONE
2016 D4 Landmark (Surely the last!) PD1881 rims-GONE
2017 FFRR SDV8 Autobiography (now semi-retired)
Thanks for your replies. Only once was there a loss of performance although there has been a hesitation when pulling away today. I haven't spotted any significant oil l
eaks but I will take a better look when an opportunity arises. I have to do some work on the steering rack soon and will take the arch liners out so I can check the waste gates amongst other things.2011 D4 HSE, it'll be nice if it ever works!
2014 D4 HSE Luxury. as if one money pit isn't enough!
My old 2005 D3. Now sold after 362000 on the original engine!
19th Sep 2023 5:25 pm
Waylander11
Member Since: 21 Apr 2016
Location: Leicestershire
Posts: 524
Also check mass air flow sensor just had to replace one off mineD3 in Buckingham blue now SWMBO's Mine D4 commercial
Xenon's fitted Timed climate
EGR Blanked Remapped
Remap Reversing Camera
gear box reset
updated Bluetooth
4x4 info
all done by Bodsy
Fridge fitted
Reversing camera fitted
19th Sep 2023 5:43 pm
LT
Member Since: 31 Dec 2005
Location: South West
Posts: 23803
steamraiser2 wrote:
Thanks for your replies. Only once was there a loss of performance although there has been a hesitation when pulling away today. I haven't spotted any significant oil l
eaks but I will take a better look when an opportunity arises. I have to do some work on the steering rack soon and will take the arch liners out so I can check the waste gates amongst other things.
Mine would go into restricted performance mode, which would clear after a restart.
Hopefully it's something simple like a split hose.2006 D3 HSE (Original & still the best)-GONE
2010 D4 HSE (A bit bling)-GONE
2014 D4 HSE (Almost too bling)-GONE
2015 D4 HSE (A heated what?)-GONE
2016 D4 Landmark (Written Off)-GONE
2016 D4 Landmark (Surely the last!) PD1881 rims-GONE
2017 FFRR SDV8 Autobiography (now semi-retired)
19th Sep 2023 5:53 pm
LRD4GAB
Member Since: 05 Nov 2020
Location: Tamworth
Posts: 498
Waylander11 wrote:
Also check mass air flow sensor just had to replace one off mine
Same here
19th Sep 2023 9:08 pm
BAZ8046
Member Since: 26 Feb 2010
Location: Chatham
Posts: 280
I’ve just had the elbow between the intercooler pipe and butterfly housing split.
Another one to look out for and fortunately easier to replace than the manifold!
I missed it the first time I checked as it’s not easy to spot.
Click image to enlarge
D4 2016 Landmark, Waitomo Grey.
D3 2005 HSE, Bonatti Grey, now sold but still comes back for servicing.
Defender 2002 Td5 Commercial, had a hard life but slowly being restored.
I only work so I can afford to repair my Land Rovers!
I have now had the opportunity to have a better look round the Disco. Sadly nothing obvious has popped up. The only thing I have noted is the small pipe that exits the airbox? Immediately to the rear of the fan shroud. ( the pipes to the inlets come out of this). This pipe is fixed by a little clip, one end grips the hose the other connects to the housing. On mine it seems to be loose and can move a little backwards and forwards. When the restricted light comes on the pipe is always pushed out a bit. If I shove it back in the light clears and I can clear the fault light. I'm getting a new one as the hose is manky anyway. No idea if this is anything to do with it or not. After playing with my iid today the passenger door lock fault cleared .. a first. Drove over a 100 miles after that without a restricted performance warning. Opened and closed the passenger door and the fault returned for the door and the restricted warning was back. Back in the days of my D3 a blown bulb could make it throw a fit. Maybe this is a similar thing?2011 D4 HSE, it'll be nice if it ever works!
2014 D4 HSE Luxury. as if one money pit isn't enough!
My old 2005 D3. Now sold after 362000 on the original engine!
Several weeks have passed without a positive resolution to my restricted performance issue. It has progressed to the red triangle stage which is only cleared using the iid tool. This is making the Disco pretty much un-useable for anything but local trips.
However there does seem to be a pattern emerging. It definitely is not a cracked inlet manifold or any other hoses or piping. I have a smoke tester and have used it at length. The only leak I found was a tiny weep on the air box lid where the filter sits. Upstream of the MAF sensors and caused by overtightening of one of the screws. No issues with the rest of the engine pipes and hoses. The grubby MAP sensor has been changed for a new one. No difference whatsoever.
In operation the fault appears most often when the engine and gearbox are cold, particularly if pulling the trailer up a gradient or accelerating briskly. I have checked the gearbox level which was high, and now dropped to the right level, The oil itself is spotless and had clearly been changed very recently. The car apparently had a service just before I got it. No fault codes relating to the gearbox shows on the iid. The fault is not always present. Today I took it out for a run after it had sat ticking over for a while recharging the battery, post another smoke test. I literally gave it a good thrashing, way above my normal driving style, trying to get the fault to re-appear. Nothing. It went like a rocket, reminding me just how powerful it is, no knocks, rattles or smoke but also no fault lights.
So I am starting to run out of ideas. I am intending to do a black reset before my next outing with a loaded trailer and to make sure my (new) battery is fully charged before setting off. If that changes nothing I may do a system update as I notice a large number of updates are available.
Any ideas?2011 D4 HSE, it'll be nice if it ever works!
2014 D4 HSE Luxury. as if one money pit isn't enough!
My old 2005 D3. Now sold after 362000 on the original engine!
7th Nov 2023 7:41 pm
Trickysummer
Member Since: 23 May 2016
Location: Maidenhead
Posts: 19
OP do you know if the fuel filter was changed at the last service? I had a restricted performance error which was resolved by changing the fuel filter which solved the problem. I don’t know if this would trigger an error code if its the cause… could be worth a try.
8th Nov 2023 10:54 pm
popsdosh
Member Since: 09 Nov 2009
Location: cambs
Posts: 442
Had the same experience with restricted performance and going back to what we would do pre diagnostics changed the fuel filter , problem cleared . Sometimes we forget the simple things. There are many D4s running on their original fuel filters that the owners think have been changed, those that have changed them personally probably realise why.
Thanks for that, I'm about to do a full service as I have no information about its previous service history. I'll get a genuine LR fuel filter and swap it out. As it happens the door lock fault I mentioned has got much worse. The iid tool is telling me that there is a short circuit. I'm having it changed this week and it will be interesting to see if fixing that fault has any effect on the restricted performance issue.
I know that it shouldn't but my old D3 threw a fit over a blown bulb and we all know about knackered brake switches and steering angle sensors.
Its annoying that I can't track this fault down , especially as everything checks out ok on the iid tool... except the door lock. We shall see!2011 D4 HSE, it'll be nice if it ever works!
2014 D4 HSE Luxury. as if one money pit isn't enough!
My old 2005 D3. Now sold after 362000 on the original engine!
Some time has passed since I last posted regarding my intermittent restricted performance issue. I got round to changing my defective passenger door lock and checking out all the wiring inside the door. I cleared the open circuit/short circuit fault code but, typically for a Land Rover, the new lock did not work properly. After wasting a lot of time blaming the Disco it became clear that the lock was defective and, following the usual bitch fight with the LR dealer over getting it exchanged, I fitted another lock which worked perfectly. Two weeks of driving without issue followed with no sight of the restricted fault light or loss of performance. Problem fixed I thought. Until yesterday.
In an earlier post I noted that my issue appeared to manifest itself readily when the Disco was cold. Yesterday was a much colder day than the last few weeks and I had cause to head up a long steep climb from stone cold. As it changed from 3rd to 4th the RP warning came on with a drastic loss of performance. Got to my destination a minute or two later and left the D4 sulking on the drive.
Came out this morning -3c, D4 flashed up and the FBH started on cue. As the vehicle was very frosted I left it for a few minutes to clear the glass before setting off. No fault code and pulling like a train. Gear changes were fine all seems well. A health check with the iiD brought no clues, no codes just a clean bill of health. Even a repeat climb of the same hill had no effect.
With the door lock short definitely fixed I'm left with a 99.9% fixed D4 and the suspicion that the D4 being cold may have something to do with it. This mornings trip started with the temperature just off the stops .due to defrosting idling, so possibly a rise in engine and gearbox temperatures and certainly a little extra charge into the very new battery. Certainly no obvious shorts or other gremlins are apparent.
Its really disconcerting to have no codes come up and for the RF error light to come on and then clear
without any pointer towards the issue.
Any ideas?2011 D4 HSE, it'll be nice if it ever works!
2014 D4 HSE Luxury. as if one money pit isn't enough!
My old 2005 D3. Now sold after 362000 on the original engine!
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