Evening peeps!

MY12 4.4 tdv8 is acting up, and I’m struggling to determine the cause of the problem. Its symptoms are these:

1. Stronger vibration/judder in the cab when accelerating, sometimes followed by a loss of power;
2. A clean, smokeless start, followed by a strong smell of diesel fumes;
3. Now an amber DPF Full light has appeared, though the car hasn’t gone into limp mode;
4. The exhaust tailpipes seem somewhat oily;
5. With the bonnet open, I can see a rapid draw on and compression of the HR (driver’s side) corrugated connection elbow tube that connects the air cleaner to the clean air duct when accelerating in neutral.

I’m waiting for an IID to arrive to run some tests.

Any help/advice would be much appreciated.

I would get the iid tool on it as soon as poss, but if needed to be driven in meantime, you should take it for a cruise, to allow the dpf to clean itself. so, get on a motorway/carriageway, and cruise it for 30 mins, low speed, as long as you maintain more than 35mph. the oil on tailpipes could be a not completed previous 'burn' OR 'regeneration'. if you continue to drive it too slow, with the amber light, you will go to red warning, and more grief and limp mode.

Most likely that you've got an intake issue. Please search the forum, as there's hoards on this topic. You mention the right air box so, take it apart and the ducts and have a look then follow the steps below? The IID is unlikely to pick up smaller leaks so, visual inspection is your best bet. Copying and pasting from similar posts over the last week:

A full DPF is usually not the cause, it's the symptom.

Usual causes are:

1. Sooted up MAP sensor, which should be cleaned every few thousand miles. This is free so, try it first. Remove the engine cover and it's pretty obvious - has 1x T20 screw on it and a multiplug going to it
2. Have a good look at and around the 4x hoses on the 'donut' (inlet manifold) plus the two top charge hoses (the big rubber hoses at the front of the engine bay). Look for soot or oily deposits in their vicinity or white gunk. It is advisable to remove the hoses in order to have a thorough inspection
3. Failure of the seal inside the union between the throttle body and top left hose (a very common failure). This can be bodged with gas specification PTFE tape or the part needs replacing (£175 but takes 5 minutes to fit on the driveway with no more than a screwdriver). Look at the top left hose adjacent to the left airbox and follow it until you see a plastic fitting with a metal clip. It usually fails in this area so, you'd see sooty deposits around the fitting and on engine components nearby

The plastic intake pipe to the throttle body, take it off and check for a collapsed seal. Here's one with the highlighted areas showing where the seal has collapsed:

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Your last sentence would indicate a blockage on the air intake. Either a very dirty air filter or something blocking the intake to it. 2012 TDV8 Vogue (L322)

Thanks for the assistance so far.

Today, I took apart the right-side air box but couldn't see anything causing a blockage. Aside from some small debris in the bottom of the box, the filter and its surroundings looked clean.

The MAP sensor, however, was utterly caked with oily soot - I've now cleaned this.

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The 4.4 TDV8 is a pretty bulletproof engine and will weather these issues so long as you get them sorted.

Looking at your photos, I wouldn't be concerned about the bell housing under the block - looks like the normal build up of crud over 10 years of use. Just keep an eye on the oil cooler and rear oil feed hose don't start leaking.

But, your MAP sensor was clearly heavily caked up and needs cleaning (including in its channel).

This says to me the main contributory cause of your issue is that union between the throttle body and charge hose. From the oily gunk on that, the seal has very clearly failed (and significantly) and is probably why the MAP sensor was all oiled up. Try the diagnostic fix with some gas PTFE or silicone tape and if it resolves the issues, consider buying the replacement part.

I would do a thorough look and even consider changing all of the air hoses anyway - a length of hose for the "donut" is less than £20 and then all you need on top of that is the two charge hoses. A good bit of preventative maintenance at the very least.

The turbo is probably only boosting a bit too hard because the ECU is telling it to because of said issues above, a blocked MAP sensor and an intake leak. Sort the intake issues first and let all the crud burn off and if no luck, then start investigating further.

The vehicle will thank you taking it for a run and giving it an opportunity to do a DPF burn. The user manual says a minimum of 50mph and for a minimum of 20 minutes. I also like to chuck in a few 50-70mph hard accelerations, to clear any oil out of the secondary turbo (engine needs to get above 2,400rpm). This will result in white smoke out of the exhaust. Once clear, no more accelerations required. Finding a dual carriageway or motorway just before sundown is great time to go and do such thing. 2015 Range Rover Autobiography 4.4 SDV8

Nothing out of the ordinary there. That broken coolant joint needs fixing ( expensive part or DIY solution) and seal the main TB joint as said but still not sure how the air box to intake hose is collapsing when revving the engine under no load unless it’s blocked or has a restriction upstream so maybe worth checking this again. 2012 TDV8 Vogue (L322)

This was mine, incredible how much crap gets in there.

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JayGee wrote:

Nothing out of the ordinary there. That broken coolant joint needs fixing ( expensive part or DIY solution) and seal the main TB joint as said but still not sure how the air box to intake hose is collapsing when revving the engine under no load unless it’s blocked or has a restriction upstream so maybe worth checking this again.

To be fair it's probably a Ford part / design. 2012 TDV8 Vogue (L322)

The MAP sensor, intake manifold and throttle have been completely stripped, cleaned and reassembled, with 4 new hoses to the "donut" and tape on the throttle body. With so much gunk, I’d be surprised if anyone ever opened it up before my tenure. Thanks for the heads up, garyRR.

Before:

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Radio silence…

Low oil level - when was it last serviced?
Excessive oil use can be caused by leaks or worn turbo seals which will also cause more oil in the intake ( it's impossible to have no oil in the intake of turbo cars)
No idea why one intake would have more oil residue than the other.
How does it drive now it's been cleaned up? 2012 TDV8 Vogue (L322)

Was the oil low because it was last serviced a while ago or because whoever serviced it didn't put the correct amount in?

It's normal for the 4.4 TDV8 to use a little oil, namely small losses over time from the secondary turbo, plus the usual little bit of gunk running through the charged air system but, over a typical service period of 7,000 miles, this should be between nothing and 200ml (which on an engine holding nearly 10 litres of oil is nothing).

The 4.4 TDV8 isn't really known for burning through oil otherwise, more so from leaks. So, as part of your maintenance, do a regular inspection of the oil cooler with a powerful torch (can be seen through the gaps in the donut), bell housing and with a mirror to inspect the rear oil feed pipe (you need to remove the cabin filter assembly to see this). I'd also run a finger along the top of the sub frame rails to confirm if they are dry or have oil on in any places. 2015 Range Rover Autobiography 4.4 SDV8

So the beast previously had an oil leak from the oil cooler. However, I can't see any reference to the garage that replaced the cooler, topping up the oil. That might be why its level was so low.

The engine is still excessively vibrating and running rough (when idling and accelerating) despite me replacing the leaking pipes on the donut and throttle body and changing its engine oil and filter elements (oil, fuel, air and pollen). When I place a long, thick screwdriver between the top of the injectors and my ear, I can hear a loud and relatively quick tick, tick, tick at cylinder 6. I've also received fault code P0306-00 (27), "Cylinder 6 misfire detected". As such, I tried disconnecting cylinder 6's wire harness and received a fault code indicating the harness had been disconnected. Would this signify that the harness works while the injector might be faulty? Is there a way to verify the harness is working (I think it's too short to switch with its neighbouring injector)? How about with a multimeter?

Tomorrow I'll also try a fuel leak-off test to see if the injector at cylinder 6 or any other injectors, for that matter, are causing problems too.

Any suggestions for any other steps I should try?