Looking at the new plenum it's clear to see just how split the old one was around the inner seam.

OLD :

Click image to enlarge

Dare I ask how much the new part was?

Not cheap that's for sure. I shopped around and the cheapest genuine part I could find was £483.54 This was for the latest incarnation of this part which seems to have been superseded many times over the years. It's a lot of money for a piece of plastic  2011 TDV8 Vogue SE

Very obvious
Looking forward to update  Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
My preferred specialist: www.glenrands.co.uk
--------------------------------------------------

Finally got everything fitted and ready to test. Took it for a drive down the motorway but sad to say the problem is still the same. Engine up to temperature and soot level slowly going up despite sensor 3 reading 615g Sensor 2 stayed around 450c. Oddly whilst monitoring the levels on the way back home I found that whilst driving at 50MPH on an A road that meant stopping at lights and having to drop to 30MPH twice due to speed limit changes, if sensor 2 read a higher temperature than sensor 3 the soot level would drop, albeit only small amounts. I left home at 19.5G and reached 20.6g on the motorway, by the time I got home I was reading 18.1g. So from that I think it proves that something is causing sensor 2 not to get up to temperature. On another note I stopped at a coffee drive through and could smell what appeared to be exhaust fumes? Hard to say exactly but it was definitely something other than unburnt diesel.

Ran faults check and once again had the following as shown below but this fault won’t clear. I am thinking it would be better to spend my money having a brick wall built so I have something to bash my head against

Click image to enlarge

What is your DPF pressure differential v reading ?
At idle and under throttle?

if at idle it is 0.9v then it might be time to have the dpf off and cleaned.
Normal is 0.7v at idle, under acceleration 0.9 to 1.2

Your regeneration is running but for how long was it holding at over 600c ?
Btw the other sensors don't go this high, only the one.
.

Also best doing regeneration using cruise control and also don't forget 1/4 tank fuel minimum . under 1/4 tank it won't regenerate.

. Cheers, Greg
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2011 Vogue SE 4.4 with lots of toys in Stornaway

Last edited by GGDR on 8th Aug 2021 7:11am. Edited 1 time in total

Hi Greg many thanks for your response

Volts readings are within tolerance showing 0.757v at idle and just over 1v at 4,000 RPM.

General consensus on here is that bank 1 sensor 2 is the one that should read in excess of 600c, I have that reading but on the wrong sensor which is odd. The highest temperature will hold for a few minutes, possibly 5 before dropping to the high 500’s.

I’ve had the DPF removed and cleaned and sat on the motorway prior to replacing the plenum for an hour at 55MPH on cruise with no success. I was hoping that the plenum being changed would finally give me a proper regeneration, sadly this hasn’t been the case. I’ve had a high pressure smoke test carried out which lead to the passenger inlet manifold being replaced. There are no other errors logged other than the one posted above. 2011 TDV8 Vogue SE

Quote:

Volts readings are within tolerance showing 0.757v at idle and just over 1v at 4,000 RPM.

Quote:

General consensus on here is that bank 1 sensor 2 is the one that should read in excess of 600c, I have that reading but on the wrong sensor which is odd. The highest temperature will hold for a few minutes, possibly 5 before dropping to the high 500’s.

Quote:

I’ve had the DPF removed and cleaned

Quote:

and sat on the motorway prior to replacing the plenum for an hour at 55MPH on cruise with no success.

The drop from say 620c will go down to around 550c at its lowest but rises again pretty much as you mention going back to 600+c in increments of between 5 & 10c at a time.

You mention maintenance burns, this is exactly what I see except if on the motorway at a constant speed of say 55MPH to 65 MPH ( I’m trying all sorts at the moment) when the soot level will just rise slowly despite the temperatures being at regeneration ones.

I’ve read that the IID tool is looking to have the regeneration option added but haven’t had any news to say it’s now out of the beta phase. It’s certainly something that we could all do with. I will have a read through your post to look at your temperature readings on the sensors  2011 TDV8 Vogue SE

So how long is it burning at over 600 ? in total?

. Cheers, Greg
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2011 Vogue SE 4.4 with lots of toys in Stornaway

It will burn at 600c for between 5 - 10 minutes at best before dropping to 595, 590, 585, etc down to a low of 550c before climbing back up to a maximum of 620c where the process repeats 2011 TDV8 Vogue SE

Forgot to say Greg that the DPF was reset upon refitting after the clean (Told car it had a new DPF via IIDtool)

Just had a read through your post and it shows that sensor 2 is indeed the one that should be reading in the 600’s

All I need to do now is find out why mine shows these readings on sensor 3

If only it were that simple  2011 TDV8 Vogue SE

Quote:

It will burn at 600c for between 5 - 10 minutes at best before dropping to 595, 590, 585, etc down to a low of 550c before climbing back up to a maximum of 620c where the process repeats

I’ll be providing an update soon on the family friend tdv8
My gut feeling dennij is you may not be doing enough longish journeys. Please tell me otherwise  Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
My preferred specialist: www.glenrands.co.uk
--------------------------------------------------

@Rob and Dennis,

I don't think the journey type or length is a factor here. mine has regenned at 30mph and while sitting at the lights!

Dennis your car its displaying EXACTLY the same symptoms as mine (to a tee!!). I have had exactly the same repairs done as you (inlet manifold, DPF clean etc). I think the fact that your car initiates a regen (hence the small reduction in soot) and not completing it means the temps are not being held long enough.

In mine it was the Thermostat housing had been cracked and was open all the time, the sensor over-reading the temps (i.e. Thinking it was hotter than it was in reality, this starting the cooling process erroneously) This meant the fans were always on and the engine temp was too cool. Do your fans seem to come on all the time? Mine hardly ever now.

I would look again at the internal engine temp whilst running and the cooling system/thermostat.