Hi All,

I'm new here, just bought an RRS TDV8 (an upgrade from my TDV6 Disco 3).

I'm only a few days into my ownership (private sale) but am unfortunately expericeing an engine issue!

The engine runs rough when started from partially cold - no problem at all when cold (left overnight), no problem when started from operating temp (say 10-20mins after shut down).

There are no issues when it's in Park, it's will run up and down the rev range nicely and sounds perfect. However when it's partially warm/cold it starts on the button and revs up and down in park - but as soon as you put it in any gear (with foot on brake) it runs lumpy and surges heavily when trying to move forwards or backwards (only when partially warm).

A short drive frees it up from any of these issues at all and they won't come back until it's started from partially warm again.

The mileage is 137k miles - the service history is complete (inc transfer box oils etc) and last service was 10k miles ago so it's due but not exactly overdue.

I have an invoice for a new injector fitting 3k miles ago due to rough running but it ran perfectly when I test drive it!

I understand it has been run on supermarket fuel and only really covered short journeys over the last year.

Can anyone help me with what it might be so I can take the right plan of action?

As I say, once it's up to temperate it's absolutely spot on, as it is when starting from first thing in the AM. It's just a Luke warm start up that causes the problem.

If anyone can suggest what it might be that would be amazing!

Get the codes read which might show where the issue is.
West 4x4 in Bishops Waltham is your man in south Hants  Visitor from fullfatrr.com
* GONE. 2012 RR Sport HSE SDV6 Orkney Grey. Now being piloted by RRSTDV8
* Current: 2011 4.4 TDV8 Full Fat. Amazing piece of kit.
* Current. 1974 Lightweight 2.25L petrol. Old skool
* GONE. Freelander GS TD4 Manual MY2013. Orkney Grey with privacy, cold and clearview packs, armrests (a must!) and a spoiler.
* GONE. Range Rover Classic '93 200Tdi Factory fit
* 1949 80" in family since 1975

Agree that reading the fault codes is the logical starting point.

If making a wild guess I'd suspect a faulty temperature sensor and the likely culprit might be the oil temperature sensor. It is fitted at the bottom of the sump near the oil drain plugs. I once changed mine on the driveway in 5 minutes. Just unscrew the old one then quickly screw in the new one before much oil is lost. Cost about £30 IIRC.

Need to remove the engine protection plate first of course. 2008 MY Java Black TDV8 HSE

Well now that is impressive Paddi!

Took a short trip out to see Mark at West 4x4 earlier and before I arrived he said "I think I know what thats likely to be but lets see what the magic box says".

Low and behold, apart from some old communication error codes the main error code was "Engine Oil Temperature Sensor values outside expected requirements" or words to that effect!!

Live values were jumping from 0 degrees to 22 degrees and all the numbers you can think of in between within fractions of a second!

West 4x4 had none on the shelf so booked in to be replaced later on this week!

The live EGR valve values were a little bit of an issue but not so bad as to warrant them as being the main source of the problem (instead of smooth curves on the graph there were jumping up and down a bit but as they where both doing roughly the same thing at the same time and both in sync) so this was put down to wear. They closed and opened as they should just more erratic than new ones.

Fingers crossed the Oil Temp Sensor does the trick!

I'm not counting any chickens until you report back after the sensor is changed. Regarding the live EGR values I was a bit surprised to see them jumping around so much on my own vehicle too but they are different from those on the TDV6 and I think the constantly changing values might be normal. Unfortunately there seem to be no 'control' traces published to use as a comparison. 2008 MY Java Black TDV8 HSE

Ok - sit rep! Oil temp sensor replaced... No change at all!

Sure the Oil Temp sensor now doesn't get thrown up as a code in the diagnostics so that's one thing fixed at least!

The EGR valves where re-visited and they still read all over the place (together so they are in sync) but it's hard to read the values unless you put your foot down where they both read 5% as expected.

What I find odd is that the problem is only present in gear (any gear), starts perfectly, sits at idle perfectly, runs up and down the rev range smoothly (in park or neutral), throttle response is lovely etc - put your foot on the brake and select any gear (drive, reverse, sport etc) and it suddenly becomes a 2 cylinder engine that wants to jump about so much you struggle to stay in the seat!

Try and drive off and it surges up and down in power and isn't happy at all!

A few mins of driving later and all is well (regardless of engine temperature state) it's as if it's decided it's actually an engine and not a bag of spanners!

Having said that my MPG has gone through the floor and it is always running rich (it even smells rich when you get out after switching it off).

Do I go ahead and get the EGR valves changed for new ones in the hope they fix the problem or would I be throwing £800 at something that isn't the problem at all I wonder?

Check the injector live values

Fault codes read on Monday (apart from the odd electrical gremlin signal fails to speed control module and terrain control module which all work 99.9% of the time) were...

Oil Temp Sensor (now replaced and fixed)
Cylinder 2 balance - injector restricted
EGR Position sensor C min/max stop performance - general signal failure

Codes read on Thursday after Monday's clear down were...

Cylinder 4 balance - injector restricted
EGR sensor A - circuit low - general signal failure

And driving to the garage on Thursday it threw up the Orange check engine light on the dash with the codes above in the ECU (which has been re-set and not come back since)

I was advised that because the injector balance codes are jumping around between injectors and that both EGR's had now thrown up codes (plus the orange check engine light) it was most likely that the EGR's were the main cause of the problem.

The live injector values were looked at and all appeared healthy, within range and all in sync (at the time of testing when the engine was up to temp and running normally which was probably not the best time to check them).

Given the above would you guys consider the EGR's to be the likely culprits here as well?

I have it booked into Avon Tuning next week for a full EGR blank off and map out. They have done loads of TDV8's (two alone this week) and there is a TDV8 owner in the staff who has also had his done without any problem.

Mark is a highly rated chap in the area
Lots of the local Disco3 forum guys use him
I'll probably use him when mine is a little older and out of LR warranty..... Visitor from fullfatrr.com
* GONE. 2012 RR Sport HSE SDV6 Orkney Grey. Now being piloted by RRSTDV8
* Current: 2011 4.4 TDV8 Full Fat. Amazing piece of kit.
* Current. 1974 Lightweight 2.25L petrol. Old skool
* GONE. Freelander GS TD4 Manual MY2013. Orkney Grey with privacy, cold and clearview packs, armrests (a must!) and a spoiler.
* GONE. Range Rover Classic '93 200Tdi Factory fit
* 1949 80" in family since 1975

I agree - Mark @ West 4x4 is fantastic! He's been really helpful through my fault finding.

What he can't do (unfortunately) is blank off EGR's and deal with the relevant software requirements (at the moment).

He has quoted to replace both EGR's at a really good rate - but thats still £500 more than blanking them off and having the software dealt with so the car does what its supposed to do without them.

Physically blanking them off and sorting the software stops the problem from ever returning again, its £500 cheaper than fitting the replacement EGR's, plus a little better MPG and smoother running etc so thats got to be the best route.

I was just wondering if the injector faults where a symptom of the faulty EGR's or if I have two separate problems I think...

Interesting thread. Something seems very odd though. If the EGRs are faulty, would the engine run normally when cold or up to full temperature? Still sounds like a problem with incorrect fuelling possibly due to the engine ECU receiving false information about temperature during the warm-up phase.
There are two further temperature sensors one for engine coolant and one on the transmission mechatronic PCB. Would be interesting to see live values of these. 2008 MY Java Black TDV8 HSE

Well took a trip to Avon Tuning today (2hrs each way but they have done over 50 EGR deletes on TDV8's in their time and produce their own EGR blanking plates from laser cut sheets).

Driving there I was averaging 22mpg and the engine didn't feel right at all, like I was constantly driving on a rumble strip.

3hrs later and I was driving back in a different car (alright, same car different engine)! Absolutely smooth as silk and to top it off I arrived home to see that I averaged 31.4mpg on the return journey!

The proof came later after I let it cool down (but not to stone cold). An hour later I went out to re-start it expecting the usual rough running, white smoke, 3 cylinder problem I had been experiencing the last few weeks! Low and behold it fired up perfectly, sat at idle perfectly and better still I dropped it into gear and it still ran perfectly!!

I should really give it a few days before I say it's all good, so here's hoping - however initial report suggests that EGR's on the TDV8 can cause all sorts of weird and wonderful problems even if they only occasionally throw a fault code without the dash light!

My suggestion to any TDV8 owner would be to blank your EGR's even if only to take advantage of the increased MPG you can instantly receive (good EGR's or not).

Looks like you've seen the last of your issues, great result. If you don't mind, what was the cost for the EGR delete?

Glad you got it all sorted cue_ball80, I live in Fareham too I may see you around! 2006 RR Sport Supercharged Love this car
2009 BMW 335D GONE
2008 VW R32 GONE
1999 RR SE GONE
1994 RR HSE GONE
2001 VW V5 GONE

Cost £300 to blank off and alter software - cheapest EGR replacement (changing both together using genuine parts) was £815inc VAT. I see that as a £515 saving and never having any EGR related problems ever again, plus better fuel consumption so can't be a bad thing!

£300 wasn't too bad considering it takes around 3.5hrs to do the physical blanking given the EGR's location etc.

Started and ran perfectly again this AM with instant power, no lag, lumpiness or poor running at all! Whoever thought it was a good idea to re-circulate burnt fuel and air back around through the engine needs shooting - in fact I think they should be forced to consume (recirculate) their own spent waste!! Haha...