BeCM will draw around an Amp (maybe a little higher on an early car) so it does look like it is sleeping. Quiescent draw when everything is off should be between 0.025 and 0.04A so you've definitely got something that is staying on. 0.35A would equate to around 4W on top of the normal draw, so do you have a light bulb (boot light, glovebox light, etc) that is permanently powered and staying on for some reason? The permanently powered interior lights are fed from fuse 15 so I would start by pulling that and seeing if the draw drops. Don't forget that clamp on meters aren't that accurate at very low current draw (or mine isn't anyway), so confirming with a conventional meter in the battery lead might be a good idea too.

As you have by now surmised, you have no flow through the radiator, so that is either water pump or thermostat. Not sure about the P38 one but modern thermostats tend to fail open rather than closed. As you say, the viscous only really does anything if you are in traffic and there is no airflow through the radiator, moving at 50 mph you hardly need the fan even.

Not long after I'd found the problem my neighbour wandered round to see how I was getting on so I showed him what I'd found. As he said, if I hadn't been able to find it myself, where would I go? Ashcrofts are the transmission experts but they rebuild gearboxes so won't get involved in the electronic side of things. He admitted that had it been taken into the LR approved Indy he had recently retired from, none of the technicians there would have known where to start and neither would an auto electrician. But, I suppose it was a case of I broke it so I had to fix it......

Definitely an I've started so I'll finish job and I'm happy to report that I've finally cracked it. Figured that it had to be a wiring problem and had found a new looking cut in the outer sheath under the car so rather than try to investigate it laying on my back underneath, decided to take the centre console out. Far easier said than done and the connectors for the loom are under the sound deadening, which is under the carpet under the centre console. Finally managed to get to them and they appeared fine so poked the loom out through the floor so it dangled under the car. Disconnected it from the transfer case so was able to pull the back of the loom out from under the car and at least see it in daylight. Pulled the sheathing back and found one wire had been damaged, the insulation was cut but the conductor was fine. Insulated that and put it all back. On the offchance I had disturbed something, tried the car and still had the Gearbox Fault.

Working forward, I unplugged and checked all the connections to the gearbox itself, nothing wrong there either. All that left was the horrible 6 way Supaseal connector that hangs down behind the LH cylinder head (the one that always gets in the way when trying to take the LH cylinder head off). That looked fine from both above and underneath but decided to unplug it to have a better look. Figured it would probably be easier to unplug it from underneath, got hold of it and as soon as I moved it, this happened.......

Two wires just fell out. Now I may have caught it with the bracket on the gearbox dipstick tube when I'd taken that out or it may be that they were broken anyway and moving the loom while changing the gearbox had allowed the wires to move out enough that they were no longer making contact with the terminal I have no idea. All I know is that the wires all appeared connected and pushed into the plug when I initially looked at it but they came out as soon as I touched it. Unplugged it, dropped it down so it was hanging under the car, found a suitable piece of stranded multicore cable and soldered that to the wires after cutting the plug off. Passed the cable up the bulkhead, snipped the wires from the socket and soldered them too. Each joint was insulated with glue lined heat shrink, then all taped up at both ends too. Started the car and everything was fine, no more Gearbox Fault, all I had to do then was reassemble the centre console. Maybe I should have started at the front.....

Anyway, I can report that the car now drives perfectly. Gearchanges are so smooth they can't be felt or heard, all you can hear is the revs changing. So while it may have taken 3 days longer than originally expected, it's finally done. It's definitely one to bear in mind when that plug has to be disconnected when a cylinder head is removed. No point doing the head gaskets only to find you end up with a gearbox fault instead.

Persistence doesn't have anything to do with it, I need it back on the road and usable. Particularly as it now looks like I caused the problem so I need to fix it.....

Probably not but it gets curiouser and curiouser. Spoke to Dave this morning and he has never had to change a gearbox ECU when swapping a 4HP22 on a 4.0 litre with a 4HP24 from a 4.6 and has done it at least 30 times on different cars, both GEMS and Thor, with no problems. This makes perfect sense as the only thing that is different is the gearbox and while it has an electrical connection, there's no electronics in the box itself, just the solenoids and output shaft speed sensor which are the same no matter what gearbox is fitted. After telling him what I'd found, took a run over to him. Running it with the gearbox ECU from the Ascot in there and the Nanocom plugged in displaying the gearbox inputs, it ran and shifted perfectly. Change points are a touch higher than with the old box but I always thought it changed up a bit too soon anyway (and at lower revs than the Ascot too). We tried all 3 variants of GEMS 4.6 gearbox controllers and all act exactly the same. He was as puzzled as I am.

Connected my graphical meter to display the torque waveform from the engine ECU. It is supposed to output a 12V PWM signal that will vary with engine speed and load. With the ignition switched on but the engine not running, it shows a near perfect square wave of around 8V peak and wide ON pulses. At that point the Nano shows an engine power of around 15 (not bad for an engine that isn't even turning over!). Start the engine and the pulse widths reduce slightly and the Nano shows a power reading of 50 ish, rising with revs. After around 20 seconds of running the pulses change completely to a very narrow pulse but at a level of only 0.7V. It is when this change happens that the power reading on the Nano changes to 236. Tried it without the Nano connected and the pulses changed just the same but as soon as they do, Gearbox Fault pops up and the gear display goes out. So, we now know what is causing it but not why and both agree that it is an electrical fault rather than anything wrong with the gearbox itself. A swift Google for P38 Engine Torque Fail, came up with this thread which describes that exact same symptoms I have https://www.rangerovers.net/threads/nanocom-engine-torque-fault-on-1995-auto-4-6-gearbox.334994/. That seemed to suggest a misfire, which I don't have, would cause the torque figure to drop and trigger the fault although I don't have a torque figure that drops, I have one that rises? In theory that should simply make the gearbox ECU think I had booted it. Although the writer of that thread didn't check and see the disappearing pulses from the engine ECU though.

Having got back home, with a spare gearbox ECU identical to the one from the Ascot, which Dave gave me. I wondered if I had some sort of incompatibility between my plod spec engine ECU and the 4.6 gearbox ECU. So, with the Ascot gearbox ECU in the car I pulled the Ascot engine ECU out of it too. Using the Nano Security Learn feature, paired it with my BeCM. Monitored the Torque pulses from it and the same. Perfect PWM signal with ignition on, start the engine and after 20 seconds the pulses disappear. While the Ascot engine and gearbox ECU's work fine in the Ascot, they don't in mine. Tried my engine ECU in the Ascot and the pulses don't disappear and it behaves perfectly. Swapped everything back so the Ascot was back to as it was and my car was but with another gearbox ECU identical to the one from the Ascot. Time for a coffee.....

While drinking my coffee I had another read through the thread. It isn't until post #15 where the actual cause of the fault is found. A dodgy connection in one of the wires between engine ECU, gearbox and gearbox ECU. Then it started to become clearer. This wiring exits the car under the centre console and dangles down underneath before going to the gearbox and transfer case. As it had been shoved around quite a lot while the two big mechanical bits had been removed and refitted, it may well be that one of the wires has been damaged. I've had a quick look underneath and found a new looking cut in the outer sheath but opening it up and the wiring all appears fine. It's quite possible that the movement has either broken a wire or caused a bad connection in one the the plugs under the centre console. So at the moment the console is partway out and I'll continue in the morning......

KCR wrote:

Hi Richard, sorry for Your gearbox :-( please give an update if the hp24 fits, as I am planning the same swap (the one from a 4.6 GEMS with a bigger torque converter). If it is plug & play (I guess the tranny ECU has to be swapped, too?) but if they are the same lengths and how the 4.0 feels with the bigger TC? Would be gr8!!!

The 4HP24 fits and is a direct swap as long as the spacer behind the flex plate is changed for the thinner one from the 4.6 so the flex plate is closer to the flywheel giving more space for the larger torque converter. Seeing them side by side, it is quite a bit larger too so I thought it might affect the feel of the engine as it is in effect giving it a heavier flywheel but it doesn't seem to, it seems to feel no different.

As noted above, it does appear that I need to change the ECU but whether that always applies or is unique to my car because it was built to police spec I've no idea. My old 4HP22 always seemed to change up sooner than I would have expected it to, and sooner than the 4HP24 in the Ascot too. That and the fact I'm seeing different waveforms between the two cars from the engine ECU would also suggest something odd.

That's a new one. I've known it when the contacts get dirty and you can't adjust the illumination level but never for them to all go out.

An update and to answer some of Dave's questions. It's in and it works, sort of..... Noticed the difference between the 4HP22 and 4HP24, the actual gearbox section of the 24 is 15mm longer but the tail housing is 15mm shorter so the overall length is the same. However, that means that while the overall length of the box is the same, the tail shaft sticks out 20mm beyond the face that the transfer case bolts to rather than the 5mm on the 22. After a bit of head scratching and measuring, realising that as the transfer boxes are identical and interchangeable, the only difference would be how far into the splines in the transfer box input shaft that the output shaft of the gearbox slides into. Measured the splines and found that they are easily deep enough to take the extra length. So as well as the other differences, the length of the splined connection between the two is greater on the 24 which, presumably gives it more strength there too.

So, after a bit of a struggle, the transfer case went back in and was bolted up to the gearbox. The main problem we had with that was supporting everything. With a large, 20 ton (overkill I know but it was given to me by a truck driver years ago and it's nice and big), bottle jack under the end of the gearbox where the mounting plate would go and the transfer case on the bracket sitting on the trolley jack, the bottle jack wouldn't allow the trolley jack to get close enough. Not wanting to support the weight of the gearbox on its sump and risk denting it, Bolted a length of steel angle to a spurious tapped hole in the side of the gearbox casting to take the weight. The other problem was getting the transfer box on the trolley jack under the car. I'd put my EAS High calibration blocks in the bumpstops so the suspension wouldn't drop and jacked the front wheels up until I could get ramps under the front wheels. The front wheels were then strapped to the ramps with the same ratchet straps used to secure cars to a trailer so it couldn't roll off.

But, it still wasn't quite high enough to get the jack with the case on it under the car. So it was Nanocom to the rescue. Plug it in, go to EAS, turn the compressor on and run that for a couple of minutes, then open the front and inlet valves so the front rose up, do the same at the back and we had at least another 3 inches of clearance. Anyway, transfer case in, and realised it would be easier to bolt up the front propshaft before the crossmember went in as access is easier. I know a lot of people have a problem getting a socket onto the propshaft bolts but I decided to replace the original hex head bolts with Allen headed bolts and had bought ones of the correct size and thread (3/8 UNF) along with new Nyloc nuts. That way all four can be done up without having to rotate the propshaft. Then it was time to refit the exhaust and crossmember. The exhaust was simple enough to put into place but the crossmember put up a fight. I'd had to use a crowbar to get it out and it needed a club hammer to get it back in, gearbox mounts (new ones) fitted and bolted up and we could finally remove all jacks from under the car, Exhaust bolted up properly, rear prop in, with more new nuts, prop guard on, connect the oil cooler and dipstick pipes, connect the wiring plugs, fit and calibrate the XYZ switch, poke the handbrake cable back up through it's hole in the floor and it was time for some fluid. At this point Dina came outside and asked how we were getting on, so I gave her a stepladder, a small funnel and two 5 litre cans of nice new Castrol ATF (at around half the price from Opie Oils than Eurocarparts own brand stuff). At one point she poured it in faster than the funnel could cope with so with ATF down the side of the engine and one exhaust manifold I knew it was going to smoke and smell a bit once it was started.....

Finally the time came to start the engine and see what happened. The inevitable cloud of smoke from the ATF all over the exhaust manifold and lots of greasy handprints on the exhaust but other than that, all seemed fine. The 4HP24 holds 11 litres from empty but there must have been a litre in there as with 10 litres, once running and checked, the level was smack in the middle of the min and max marks on the dipstick. Although the dash was showing Gearbox Fault and not displaying the selected gear in the message centre. Not the XYZ switch as the LED next to the gearlever was displaying correctly. Checked the fault code and it was giving an Engine Torque Fault, cleared the code, ignition off then back on again and the selected gear display was back and no Gearbox Fault. Started the engine and after it had run for around 20 seconds, the fault comes back. OK, but does it work or is it in limp mode? The answer is, it works, all gears engage, torque converter lockup happens and kickdown works but the changes, particularly down changes are harsh.

Checked in RAVE and it lists a fault of Engine Torque signal out of range with the affect being harsh gearchanges but no limp home mode. So that is what I have. A torque signal is sent from the engine ECU to the gearbox ECU. Thinking that maybe we had damaged the wiring (even though it is all in a protective flexible conduit) when putting the gearbox or transfer case back in, measured for continuity between the two ECUs. No problem. Then checked for a 12V PWM signal from the engine ECU and my cheapo Chinese graphical meter showed a waveform although it appeared to be showing a much lower level. Being fortunate in having another car, the Ascot, sitting there, checked that and found a completely different waveform and at a higher level too. Checked the two gearbox ECUs and found they are different (mine is AMR5493 marked 4.0 while the Ascot has an AMR5496 marked 4.6), so pulled the ECU out of the Ascot, tried that and this is where things start to get really weird.

With my original one, if I clear the fault then read the data, I get an engine power reading of around 45 at idle rising as the engine is revved, a battery voltage of 10.6V (?) and the gearbox mode as Economy (the ECU supports Normal, Economy and Sport modes although the P38 only uses Economy and Sport). After the engine has run for around 20 seconds, the power reading goes to 236, the gearbox mode goes to Normal, the dash beeps, Gearbox Fault comes up and the gear indicator goes out. In this state I get the harsh gearchanges. On the Ascot, with a 4.6 engine and 4HP24 gearbox, I get power of 52, again rising with revs, 13.8V battery voltage and gearbox mode of Economy. With the Ascot ECU on my car, I get power of 45, 13.8V and Economy mode for the first 20 seconds then the power reading changes to 236 but the gearbox mode stays at Economy, no Gearbox Fault and gear display stays on the dash. Driving it like that, it drives perfectly with super smooth gearchanges both up and down the box, kickdown works and so does Sport mode. Brilliant I think, cracked it but as soon as I exit the displayed data on the Nanocom, the dash beeps, Gearbox Fault comes up and the gear indicator goes out.

So, the situation at the moment is that with the Ascot ECU in and the Nanocom connected and displaying the gearbox inputs, it works perfectly (even if the engine power figure seems odd). The Ascot is an earlier car (96 model, VIN TA337218 showing a build in mid 96) and having checked the data on the gearbox in it, it is a model 030 061. The gearbox I have fitted is an 030 064 so would be from a 98 car which should have an AMR5692 ECU. It might be that all I need do is fit the matching ECU but I'll give Dave at East Coast Range Rovers a call in the morning and see what he can suggest as he has swapped gearboxes in the past and they have been a simple plug and play job.

Anyway, to answer one of Dave3d's questions, once the propshaft, crossmember and exhaust are off, flex in the engine mounts will allow it to drop down but as the gearbox mounts are attached to the crossmember, it'll try to sit on the floor. That's why RAVE tells you at the beginning of the gearbox removal process to remove the upper fan cowling, so you don't break the fan as the front of the engine rises. On the diesel I don't think you need to remove the crossmember to get the exhaust front exhaust pipe off, so leave it in place (in fact, I'm not even sure if you would need to remove the exhaust downpipe as it is on one side and not both as on the V8 although it might make access easier). With the propshaft off, remove the U shaped shield that is there to stop the propshaft flailing around if a UJ breaks (not that one ever should if greased regularly). There's 6 bolts holding the transfer box to the gearbox and the top two are a bit of a pain to get to, multiple socket extensions and universal joints needed. The first time I took mine off, I had to resort to using an Irwin bolt extractor (https://www.amazon.co.uk/Irwin-Bolt-Grip-Remover-Expansion/dp/B000QW6K8I) to get a good bite on them. They are flanged head bolts so the actual hex isn't that deep. My transfer case bracket is a couple of lengths of angle iron that fits onto the lugs where the bolts go and was made up with the case in the car so the bottom of it is horizontal and a suitable size socket to fit into my trolley jack bolted and welded to the bottom of it. That fits onto the bottom of the case with a ratchet strap around it to hold it in place. If I was to make another, I'd make it so a couple of the bolts on the case can be taken out and used to bolt the bracket to it rigidly. That way the transfer case can be unbolted, the bloody annoying and a real pain to get to, breather pipe can be disconnected and it can be slid backwards. Once clear it can be lowered on the jack and pulled out from under the car. Refitting it is the reverse but a couple of long M10 bolts to fit into a couple of the bolt holes to use as guides for it to go back in are useful.

I've had the transfer case off before when I put a new chain in it and even that on its own was awkward, a combination of the weight and the fact it hangs down at a strange angle. Two of us did it then with the car on a ramp but we didn't remove the exhaust so had to manoeuvre it over the exhaust cross pipe which made it more difficult. Today we are going to put it back before the exhaust and main crossmember goes back on. I'll report back later......

Gearbox off, jeez, is it heavy or what and despite it being strapped to a transmission jack adapter on a trolley jack, it still used gravity for the last 6 inches of downward motion! Decided that with the transfer case attached we, that is me and a recently retired Land Rover workshop manager, could barely move it so removed that to make it slightly more manageable. New rear main oil seal fitted, spacer behind the flex plate changed for the thinner one needed to take account of the larger torque converter on the 4HP24, and fitted an Ashcroft Transmissions heavy duty flex plate. Figured that it will be easier (as opposed to virtually impossible) to fit the replacement gearbox and refit the transfer case once it is in place. I've got a bracket I made up years ago that bolts to the transfer case and fits into the trolley jack so it is at least held at the correct angle, so, in theory at least, that should be relatively straightforward. With two of us under the car, two trolley jacks, one with the adapter on it, a bottle jack and a ratchet strap to hold it steady on the main jack, lifted it back into place. Took a bit of wiggling to get it to slot into place but it went in and the bellhousing bolts were whacked in with the rattle gun Instead of two clicks a time on the ratchet. At which point, our respective better half's told us to call it a day if we wanted any dinner.

So, tomorrow is refit the transfer case and connect everything else up. The odd thing is that with the old gearbox out, it seems to turn smoothly with no noise although thinking about it, it is in neutral so maybe it only clatters when it tries to drive. The fluid is spotless, not at all cloudy, burnt looking or with any metallic shaving in it either.

Pump running on every pedal press could point to a failing accumulator but equally can be caused by air in the system. It stores a specific amount of fluid under pressure and with a failing accumulator, that quantity is lower so is used up sooner so needs to be replenished. However, if there is air in the system, more fluid is needed when you press the brake pedal as some of it is used in compressing the air before the remainder is used to operate the brakes.

Ordinarily, when you press the brake pedal all you are doing is opening a valve to allow some of the high pressure fluid through to operate the brakes. As a safety feature, there is also a conventional hydraulic circuit which is what you are using when you have no stored pressure. That will only allow the pedal to go to the floor if it has air in it, otherwise it will feel like a conventional brake pedal where the servo isn't working. All I know is from experience when my pump failed. That meant there was no pressure stored at all so I was relying on the conventional circuit, the pedal was rock hard and I needed both feet on it to get the car to stop.

Other vehicles don't have a powered system though so air in the hydraulics has a different affect. Until pressure has built up you should have a very hard pedal that gives very little braking effort.

Soft pedal is usually air in the system, a lack of fluid pressure gives a rock hard pedal with very little stopping power. Once up to pressure, air in the system will cause a very slight delay between you hitting the pedal and the brakes coming on (as you are having to compress the air before anything moves). It is so slight that you tend to not notice it until the bleed the brakes and it goes away. Bleeding the brakes, following the steps in RAVE to the letter, would be the first call and even cheaper than a new accumulator.

Sorry, typo in my previous (now corrected), Y shows 2000 but then they ran out of alphabet so went to numbers from then on so the 1 means 2001, A means built at Solihull and 458723 is the serial number of the car.

I suspect yours is sounding just like this one that did exactly the same thing https://www.youtube.com/watch?v=dKEqPY5rX7A

The head gasket was blowing out the side to the outside world, drove perfectly OK although from underneath you could actually see sparks of tiny bits of burning gasket material being blasted out the gap when it was revved.

The letters at the beginning of the quoted VIN numbers are the model year, T being 96 (as although production started in 95, they were all 96 models), U was jumped, V being 97, W is 98, X is 99, Y is 2000 and then they started at the beginning (as Z would be too easily misread as a 2) so 1 is 2001.

GEMS models were up to WA410481 with Thor starting at XA410482 (so the year designator changed but the serial number carried on). While the actual numbers show the particular serial number for the car but that doesn't mean yours is the 458,723rd P38 as these numbers continued on from the Classic which used the same format

The rest of the VIN gives detail on the build, so yours shows it was built in the UK by Land Rover at Solihull, it's a P38 with a 4.6 litre V8 engine, a ZF 4 speed auto gearbox and is RHD.

I get the argument but it's just the monthly costs that seem ridiculous to me, particularly for a lease deal where you spend the best part of £5k a year and don't even own it at the end. OK, so with an EV you aren't paying road tax (I think) but you still need to pay the electricity bill and insurance on top of the payments.

As a comparison, my fixed costs are £25 a month road tax and £74 insurance (admittedly for a trade policy that covers me for an unlimited number of vehicles so probably more than most pay), so call it £100 a month or £1200 a year. That means I would need to spend £3,800 on repairs before it's costing me more than leasing a new car. If I didn't do any of the work myself, I still think I would be quids in paying someone else to do it. I suppose the main difference to the way I think in that I have never bought a car on finance, I reserve that option for property. I've got 2 buy to let houses and the mortgage on each of them is around the same as leasing or doing a finance deal on a new car and instead of having nothing at the end of it, there's the best part of £200k, and rising, equity in them when I choose to sell them.

I get sent a Parkers email newsletter every so often and I don't know how, or indeed why, people pay the sort of money these deals cost. £400 a month and up unless you are happy to drive something marginally larger than, and about as useful as, a shopping trolley. £400 is about what I'm spending at the moment replacing my gearbox but that is, hopefully, a once in a lifetime expense. If I was to run on petrol and it was £2 a litre, £400 would buy me 200 litres, or 44 gallons. Even at 20mpg, that's still enough for 880 miles. Not that it would matter as most of these deals seem to be capped at 8,000 miles a year. I honestly don't understand it, if I was spending that kind of money every month I'd expect to be able to drive as often and as far as I wanted.

Providing you get the right gearbox, one from a similar age GEMS, it is a straight swap. The ECU is the same, it detects engine load, and hence when changes should happen, from the MAF sensor so it doesn't need a different ECU. The only other difference is the spacer behind the flex plate is thinner on the 4.6 to move the flex plate closer to the flywheel to give room for the larger torque converter so that has to be swapped over. It's convenient that I'm being supplied with the 4.6 one with the gearbox.