Thanks. I may phone the dealer to see if they have any record of them being changed. I have a £3,500 bill for a turbo change that was carried out 2 months before I got the car (by the dealer in Devon as it went while the guy was down there) but nothing much more than that as far as actual paper receipts to go.

Blown turbo while on holiday in Devon rings a bell - do a search as it may be that the previous owner is a FFRR user. 2012 TDV8 Vogue (L322)

Will have a search. I say holiday, the car was actually registered in Devon as the bloke had a second home there, guess it was cheaper to insure it there than his Nottingham property at a guess.

Presume most of the 143k miles were put on via trips from the East Midlands to the south west.

Additives - snake oil and do nothing

Premium diesel - oil companies invest billions into research and development (and also marketing for their premium products to earn some of this back). There is a video on YouTube of a mechanic who used a boroscope on the cylinders before and after running on premium diesel and it's fair to say, there genuinely was some good cleaning effect of premium fuel but, it also wasn't night and day - there's no doubt it's a higher quality fuel but there's also no reason why your car wouldn't be happy running on the fuel it's designed for. But also, car manufacturers invest billions into engine development and one of their top priorities is to get them to burn fuel as cleanly and efficiently as possible so, there's no reason regular diesel would cause any particular build up. So, up to you on this one - it might be worth the occasional tank full but not with fuel prices how they currently are, in my view.

The best things you can do for these engines are performing an oil change every 5,000-7,500 miles, give them a long run and occasionally having a medium/heavy foot (but only once up to operating temperature) and keeping on top of the maintenance schedule.

The next best thing is to blank off the EGRs and software delete them. No, it's not an MOT fail because MOT testers aren't permitted to remove parts from a car (including the engine cover) and would therefore never be able to visibly verify the engine emissions system had been modified. I believe the EGRs only impacted emissions by around 2% on this engine so, MOT emissions tests are also still within tolerance. 2015 Range Rover Autobiography 4.4 SDV8

Thanks. My plan was to use a bottle of diesel redex I have in the shed already (wife has a diesel civic), if there are no real adverse effects aside from price there is no harm. By nature I am very maintenance focused and will be changing the oil next week as it’s been a little over 4k miles since the last one. By nature I am also quite oem focused so deleting the ERG and changing software feels outside my comfort zone! But seems there are many reasons to why it’s a good idea.

Food for thought....
An extract of a conversation I had with an ex-LR employee with regard to EGR blanking (although also related to DPF)

Quote:

Blocking EGR will indeed increase NOx values under all modes where EGR would normally be operational - that is the physics of the system.

Blocking EGR will prevent regeneration of the DPF because of the diagnostic-reaction of the ECU and its control-structure, the physical reaction of the engine has little to do with this. EGR is needed to control-down the oxygen levels in the combustion system, and is therefore a prerequisite of normal "active" DPF regeneration.

You can make a DPF "passively" regenerate, but only under high engine-speed and load operation, as exhaust gas input temperatures need to be high to start the thermal process. However, this would a) require that the secondary turbo was well spooled-up, and b) that the ECU had not recognised that the EGR valves were disabled - the engine speed and load are capped if there is/are errors in the EGR control structure, anywhere whatsoever in the system. So in practice, if the EGR valves are disabled, the DPF will eventually block-up, if the LR calibration department have done their job (which they have, by the way.......) to prevent a "thermal event" from happening under the floor and carpets. That is the reason why the engine will go into a limp-home when the EGR control structure is faulty - it stops the exhaust gases straight out of the engine from elevating too high.

There's a lot of sh**e circulated within the LR "pub circles" about everything and anything under the sun to do with engine controls. It has always been a problem for LR, and latterly for people like BMW that also seem to have inherited every "pub hero" that knows how to circumnavigate their way around engine protection-measures. It takes a lot of time and practice to fully understand how the whole lot works together, not just playing with their toy on the front-drive at weekends. I reckoned on around 3years before anyone was competent to let-loose on a diesel engine, and that is after a lot of testbed experience.

The best advice I can give anyone is this: If you don't understand what you are doing, leave it alone. There are over 2500 maps, curves, and constants in the most basic of diesel EDC control structures, any one of which can potentially render the vehicle unsafe, non-compliant on emissions, or just downright awful to drive. The TDV8 has lots more than that, especially in DPF-format (the whole control system is pretty much duplicated for DPF regeneration-running, to match the engine reactions with/without regen strategies perfectly).

I would go one step further on my advice for "Forum Phil" to leave this sort of stuff well alone: Any change in the control structure can be seen in retrospect by both LR and Siemens/Bosch, and it cannot be hidden. Each change is stamped indelibly into non-volatile memory on the ECU - that is why, for example, early controllers from Siemens have a flash-hierarchy in the ECU, as the top "boot" block (Siemens-only flash) has the monitor over this sort of thing. If a roadside stop was made, it would be feasible to examine such a record. Whether it was emissions-compliant or not, there would be some serious questioning of the operator of such a vehicle, especially in a ULEZ or a post-RTC report.

Thanks. Interesting to read the pro’s and cons from different perspectives.

Just to say most 3.6 cars and all UK cars don't have DPFs so, that LR 'employee opinion' also sounds no different to the pub circles!

That said, yes, on the 4.4 TDV8 where most cars do have a DPF and all UK cars do, it is not advisable to de-activate the EGR and most of us owners don't. 2015 Range Rover Autobiography 4.4 SDV8

Simple question - is there any way to check the health / condition of the EGR valves? Or is it a case of keeping a look (and ear) out for specific running issues?

Loads of info on the operation (and failure) of 3.6 EGR valves if you use the search function  2012 TDV8 Vogue (L322)

I have recently gone down this route of EGR blanking as a DIY. I chose the simple flat plates on eBay which once fitted cannot be seen, unlike the more expensive option where parts are removed and the result is clearly obvious to the trained eye. Took no more than an hour to do. I cannot comment on any improvements on running or economy as I did it as soon as I got the car, like yours a one-owner full dealer history. Never had any warning lights or hiccups. After 6 Months I decided to go the full hog and got an ECU remap with the EGRs deleted. This gave an immediate 10 to 15% increase in the economy and a subtle but impressive increase in performance, I would not hesitate to do it again. 2007 TDV8 VSE
2003 TD6 gone.
2002 P38a gone
1999 P38a gone
1997 p38a gone
1993 VSE gone
1992 VSE gone
1966 Series 2a with V8 conversion gone

Thanks. Where was it taken to be remapped?

Apologies, just seen you are in Australia! Little far to drive from where I live…