Thread: 2011 D4 'Gearbox Fault' warning

Well done! My celebrations were short lived when a fuel leak gave me 5 days of hunting and tweaking and fixing to make it go away.

Lots of good info here, i may be staring down the barrel of HPFP replacement in the near future, something i had been dreading for years.
I think its one of the 3 big ticket items, engine,trans and HPFP.

@ Loanrangie whilst I don't envy you I can say that the only thing that made the job difficult was getting the oil separator in and out. Even with the helpful pointers from members and videos online, it was still a massive struggle and a test of patience. Most other jobs were far less daunting than I was thinking they could be. You take a fair few bits off and disconnect all sorts of connectors, but if you take lots of photos and are organised it all goes back together easily (all except the oil separator!!). Apart from this, having the wrong belt didn't help and messing up the fuse holder for the LPFP fuse had me guessing. I don't want to do another, but I would feel pretty comfortable the 2nd time around.

But I feel like a true Land Rover owner now and it looks like the group diagnosis - faulty HPFP / pressure control valve - was correct or partially correct at least. I'm not out of the woods yet. Shak and Loanrangie might have called it: more than one issue. With 320k, I'm not surprised.

There appears to be something still not quite right in the transmission. Perhaps torque converter, perhaps solenoids and sleeves. Or both. Does anyone have any suggestions on a process to diagnose using the GAP?

I'm not getting any codes but I get a slight shudder every so often (TC no doubt), but what really has me guessing is an occasional series of surges I described earlier in this thread. It happens most when coasting up a hill in D. Putting my foot down or shifting to S cures it immediately. If I try hard enough I can get it to do it in S too but it's barely noticeable. It feels to me like a gear change is being initiated but then decides to stay in the current gear or like tapping the clutch pedal in a manual. With the HPFP changed it seems that the 'Gearbox Fault' has gone away and the engine in general just feels so much more lively. So it would be good to find a cure in time for this too. I don't mind just ripping in and changing the solenoids and sleeves anyway but the TC is above my LR owner status for now.

I'd like to get on and clean the injectors next. I would prefer to pull them to check the spray patterns but then again I'm not against a lazy bottle of additive in the diesel tank. Does anyone have any advice either way?

Thanks far all of the help so far.

Originally Posted by Bananas

@ Loanrangie whilst I don't envy you I can say that the only thing that made the job difficult was getting the oil separator in and out. Even with the helpful pointers from members and videos online, it was still a massive struggle and a test of patience. Most other jobs were far less daunting than I was thinking they could be. You take a fair few bits off and disconnect all sorts of connectors, but if you take lots of photos and are organised it all goes back together easily (all except the oil separator!!). Apart from this, having the wrong belt didn't help and messing up the fuse holder for the LPFP fuse had me guessing. I don't want to do another, but I would feel pretty comfortable the 2nd time around.

But I feel like a true Land Rover owner now and it looks like the group diagnosis - faulty HPFP / pressure control valve - was correct or partially correct at least. I'm not out of the woods yet. Shak and Loanrangie might have called it: more than one issue. With 320k, I'm not surprised.

There appears to be something still not quite right in the transmission. Perhaps torque converter, perhaps solenoids and sleeves. Or both. Does anyone have any suggestions on a process to diagnose using the GAP?

I'm not getting any codes but I get a slight shudder every so often (TC no doubt), but what really has me guessing is an occasional series of surges I described earlier in this thread. It happens most when coasting up a hill in D. Putting my foot down or shifting to S cures it immediately. If I try hard enough I can get it to do it in S too but it's barely noticeable. It feels to me like a gear change is being initiated but then decides to stay in the current gear or like tapping the clutch pedal in a manual. With the HPFP changed it seems that the 'Gearbox Fault' has gone away and the engine in general just feels so much more lively. So it would be good to find a cure in time for this too. I don't mind just ripping in and changing the solenoids and sleeves anyway but the TC is above my LR owner status for now.

I'd like to get on and clean the injectors next. I would prefer to pull them to check the spray patterns but then again I'm not against a lazy bottle of additive in the diesel tank. Does anyone have any advice either way?

Thanks far all of the help so far.

Your shifting issue was pretty much what i was getting, it would shift 1-2 okay but the 2-3 falters and it goes into limp mode and locks in 3rd.
Light throttle it was ok but if i pushed it up a slight incline it would fault.

Originally Posted by Bananas

I'd like to get on and clean the injectors next. I would prefer to pull them to check the spray patterns but then again I'm not against a lazy bottle of additive in the diesel tank. Does anyone have any advice either way?

Thanks far all of the help so far.

I'm onto the 2-stroke oil now 1 litre occassionally per full tank.

Originally Posted by Bananas

@ Loanrangie whilst I don't envy you I can say that the only thing that made the job difficult was getting the oil separator in and out. Even with the helpful pointers from members and videos online, it was still a massive struggle and a test of patience. Most other jobs were far less daunting than I was thinking they could be. You take a fair few bits off and disconnect all sorts of connectors, but if you take lots of photos and are organised it all goes back together easily (all except the oil separator!!). Apart from this, having the wrong belt didn't help and messing up the fuse holder for the LPFP fuse had me guessing. I don't want to do another, but I would feel pretty comfortable the 2nd time around.

But I feel like a true Land Rover owner now and it looks like the group diagnosis - faulty HPFP / pressure control valve - was correct or partially correct at least. I'm not out of the woods yet. Shak and Loanrangie might have called it: more than one issue. With 320k, I'm not surprised.

There appears to be something still not quite right in the transmission. Perhaps torque converter, perhaps solenoids and sleeves. Or both. Does anyone have any suggestions on a process to diagnose using the GAP?

I'm not getting any codes but I get a slight shudder every so often (TC no doubt), but what really has me guessing is an occasional series of surges I described earlier in this thread. It happens most when coasting up a hill in D. Putting my foot down or shifting to S cures it immediately. If I try hard enough I can get it to do it in S too but it's barely noticeable. It feels to me like a gear change is being initiated but then decides to stay in the current gear or like tapping the clutch pedal in a manual. With the HPFP changed it seems that the 'Gearbox Fault' has gone away and the engine in general just feels so much more lively. So it would be good to find a cure in time for this too. I don't mind just ripping in and changing the solenoids and sleeves anyway but the TC is above my LR owner status for now.

I'd like to get on and clean the injectors next. I would prefer to pull them to check the spray patterns but then again I'm not against a lazy bottle of additive in the diesel tank. Does anyone have any advice either way?

Thanks far all of the help so far.

ZIP GEN 2 kit, Including the end of line seals, new valve body to transmission seals, mechatronic seal and a full flush, new solenoids and filter and flush should sort that out. TC should still be OK, better do the vb before lots of crud ends up inside the TC. When I did mine it was about 1200 in parts, took a weekend to do. The hpfp sounds like it's much more work.

Originally Posted by PerthDisco

I'm onto the 2-stroke oil now 1 litre occassionally per full tank.

I'm not one to go the snake oil route but i decided to give the 2SO a go but at 400ml per tank, if it can delay the HPFP failing its worth a shot.

Update on the HPFP....
Still working like a charm. No leaks or weirdness. Time to get the guards and covers back on.

Before I move on to the gearbox I thought I'd add the resources I found helpful in addition to all the amazing help I received from everyone who responded to my questions. Many of these links are well known and some were recommended to me further back in this chain. I try to arm myself with as much info as I can before ripping into something I know nothing about. Hopefully this list will save someone some Google time.

If anyone suspects their HPFP is failing the first thing to do is to read up on BradC's experiences with the Antichrist. His diagnosis and reasoning really helped me imagine what was going on and diagnose mine. @BradC - thanks for sharing your experiences and knowledge!

Second thing, if you don't own a GAP tool, I echo the recommendations I received. I don't think I would have been as confident in my diagnosis without it. Overlaying live data graphs is immensely helpful. Perhaps other OBD readers can achieve the same but that Google rabbit hole sent me back to the GAP ID tool.

Third thing, if you don't have one treat yourself to a compact a ratchet for your sockets with as many teeth on the ratchet as you can afford. Life saver!

Diagnosis and general understanding:
DISCO3.CO.UK - View topic - Robbie's Guide To The Low Pressure Fuel System
https://www.youtube.com/watch?v=y2tjNC4qrr4

Replacement (Land Rover):
https://www.youtube.com/watch?v=Q8Q1vnPbQRw
DISCO3.CO.UK - View topic - How to replace the HPFP
DISCO3.CO.UK - View topic - Guide to change removing HPFP on Discovery 3


Replacement (Ford Territory: same engine as mine 2.7L V6):
https://www.youtube.com/watch?v=aDZeBwya0fE
https://www.youtube.com/watch?v=VeCC_5-hnvM
https://www.youtube.com/watch?v=Gup_xxbZrJA
https://www.youtube.com/watch?v=Ir3H0auWUJ8
https://www.youtube.com/watch?v=ihxdb6YG8mg