Yes, check the voltage, or wheel speed, with the Nanocom. They should all read exactly the same and as you start to creep forward, they should all start giving the same output at the same time. I've seen one where one sensor was sluggish and was slow to start giving an output which was showing the same fault as you have. A tap with a mallet was all that was needed.

If you've got, or had, an ABS fault, Traction Failure will come up on the dash when you switch off. Is it still doing it or has it now gone away? Chances are the ABS sensor on one wheel has moved and a light tap with a mallet to push it back in will be all that you need do. If it was a failed sensor, it would be detected during the self test when you first switch the ignition on and would also store a fault that the Nano could read.

If the temperature doesn't change then there is a problem with the blend motors. When the ignition is first switched on, they are driven from one end of their travel to the other and the feedback from the blend motor internal potentiometer is checked. If it doesn't show full travel, the HEVAC shuts down the output to the blend motors so they won't move when told to.

If you aren't getting a change in temperature on the pipes to and from the compressor, then chances are you have a slight leak and the refrigerant has leaked away. A simple test is to see if there is any pressure in the system still. Static pressure (when the engine isn't running), should be in the region of 6 bar on both ports, dropping to 2.6 bar on the low port and rising to 10.6 bar on the high port when working. These pressures are at an ambient of 20 degrees C but will give you an idea of what is happening.

Hi and welcome. If you intend keeping the car, you won't go far wrong with a Nanocom (https://www.nanocom-diagnostics.com/product/ncom06-range-rover-p38-edc-diesel-kit), not cheap but it will pay for itself over time. A slightly less capable, computer based, solution is the RSW EASUnlock V4 suite (https://www.rswsolutions.com/index.php/range-rover-p38a).

There's some things you can check with a HEVAC that is giving you the book symbol. Does the temperature change on both sides when you go from Lo to HI, if not, you have a faulty blend motor. Are both blowers working, take the pollen filter covers off and filters out and you can see then down the hole. If only one is working, that will cause a problem. Does it have any refrigerant in it? Leaks from the top left corner of the condenser are common. I know seeing the AC compressor on a diesel isn't easy, but can you see if the clutch is engaging? If it has refrigerant but the clutch doesn't engage, check the connectors on the pressure switches, dirty contacts aren't unknown.

Fusebox is held in place with 3 small bolts, removing those will allow it to be moved. Most people leave the sounder in place and just pull the plug out of it.

The Nanocom documentation (somewhere) does tell you to connect the cable to the unit first before connecting to the OBD port. I seem to remember seeing it when I first got mine although I could never work out why.

An odd one. If the microswitch in the lock barrel has stuck, normally the dash will tell you the key is in even when it isn't when the door is opened. It will also cause a mislock beep when locking. I suppose it is possible that it has failed open circuit so it doesn't detect the key in the ignition and that could set the alarm off when the ignition is switched on, but not as soon as the key is put in the ignition (as it wouldn't know the key has been put in the ignition). The coil around the lock barrel is there to cause the fob to transmit the unlock code as soon as the key is put in the ignition so it resets the immobiliser if passive immobilisation is still enabled. As far as I know it is only the immobiliser that comes on with passive and not the alarm too. Also, if passive is still enabled and the coil has failed so the unlock code isn't being sent, you would get the Engine Disabled message on the dash.

Alarm siren lives just towards the front and under the fusebox. On later cars it was battery backed but by now the NiCd battery in it will be well past its sell by date so it may be that it was trying to draw too much current which popped the fuse. By now it has been unplugged on most cars.....

When he unlocks with the fob, does it turn off the red alarm LED on top of the dash or does it continue flashing?

Connector is supplied with power from Fuse 33. If that has blown, the Nano won't start even.

The suspension on a particular car makes a difference too. When I first needed something to tow a car transporter to the south of France, I went for a 4x4 and, as it was needed at very short notice, I bought a Ford Explorer. Absolutely horrible to tow with. The towbar is attached to the body and that is attached to the wheels by the suspension. Being something designed for the US market, as standard it had suspension that made it handle like a blancmange so attaching the trailer to it made it wallow around like drunken elephant on ice. The trailer had far more control of the car than I did. I used it once and bought a Range Rover Classic LSE two days after getting home.....

tking88 wrote:

Yes, it dips when the AC clutch engages which I understand is normal. But then it continues to do so every 30-60secs.

Perhaps I am being stupid but once the clutch has engaged, does it remain engaged until the ac or engine is turned off?

No it doesn't, it engages every so often to raise the pressure in the system then disengages until the pressure drops to keep it in the correct pressure window. I understand the AC compressor on a diesel is a bit buried but on a V8 where it sits on top of the engine so in easy view, you can watch it continuously engaging and disengaging. As the compressor has no built in regulation, if it was to run all the time the pressure would get far too high.

Does it dip in time with the AC compressor clutch kicking in? On a petrol engine the HEVAC tells the engine ECU that the compressor is about to engage so it can adjust the Idle Air valve to maintain the idle speed. Presumably the diesel has something similar but no idea what. One of our resident diesel experts should be able to tell you.

j_rov wrote:

Richard: Does 300 miles to a take sound normal? I know you run LPG but thinking you must have done the odd full take of unleaded when you are out of LPG?

I think my fuel gauge has only ever got above half full about twice is all the time I've owned the car so have never run on a full tank of petrol. The petrol in the tank is regarded the same as the spare wheel, for use in emergencies only and for as little time as possible. In fact, I've worn out the track on the sender at just below the 1/4 full mark so it either reads below that or above it, when it hits that point it drops off the bottom, the low fuel light comes on and the dash comes up with Fuel Gauge Fault. At that point I bung another 10 litres in just to move the sender (and freshen up the stale petrol).

However, it's a 100 litre petrol tank so that is 22 gallons, 300 miles on 22 gallons works out to 13.6mpg. A bit low but with a twin axle caravan that is going to be higher than the car and being driven with the revs kept down, probably about right. Use Sport mode and give it some revs, travelling slower isn't the most economical as the revs want to be above 2,000 rpm.

Since I changed my gearbox, the new one changes up at higher revs than the old one did and my economy has improved as it is keeping it in the power band more.

I've found the thing that affects fuel consumption more than anything is aerodynamics. Even an empty box trailer will make a hell of a difference, particularly in a headwind, whereas a car transporter loaded with something that is lower than the P38, even though it weighs far more will have much less of an affect. I've also found that using Sport mode and getting the revs up makes quite a difference on hills. The speed can be dropping when the revs are down to around 2k but cause it to drop down a gear and get the revs up to 3k and it will accelerate uphill. If you can keep your speed up to 70mph, the hills don't have much affect at all as the revs are higher. Admittedly that would be illegal in the UK though (sorry officer, it has so much grunt I'd forgotten I was towing).....

Even with a Range Rover Classic on a trailer the other week, my fuel consumption was higher but not ridiculously high.

That is the difference between EER (Energy Efficiency Ratio) and SEER (Seasonal Energy Efficiency Ratio) and COP (Coefficient of Performance) and SCOP (Seasonal Coefficient of Performance). As the efficiency will change with the difference between indoor and outdoor temperature, the seasonal figures take this into account by using a fixed indoor temperature with a varying outdoor temperature and averaging the result. EER and SEER are the differences between energy consumed and energy output, so a unit that draws 1kW to solely convert the energy and outputs 4kW has a EER of 4, whereas COP and SCOP are the output minus the input (the power used to convert the energy but also that used to supply control electronics) so that same unit would have a COP of 3 (4-1).

dave3d wrote:

Ha ha. That would be analogous to having an electric car and towing a diesel generator behind it.

My other half works for Cummins and they have supplied a large number of big diesel generator sets to Australia to power remote EV charging stations......

Aragorn wrote:

The idea of switching to heat pumps for domestic heat isnt to save money, its to stop burning stuff.

Agreed, but you'd need to be a pretty fervent tree hugger to do your bit for the environment but at the same time increasing your costs. If someone can see that a replacement system will be cheaper to run and recoup the initial installation costs over a reasonable period, then they will go for it but if it costs more to install, roughly the same to run and doesn't work as well, then why would anyone go for it?

Electricity is great because it comes from many sources. your heat pump can be powered by gas, or solar, or nuclear, or wind, or hydro, or diesel, or coal. A gas burning machine can only use one source. Your electrical machine gets cleaner over time as the grid installs more renewables, Your gas burning machine doesnt.

However, there are now also electric boilers on the market that can be installed as a virtual straight swap for a gas boiler. Allegedly very efficient but I can't see them being cheap to run.

As for the operating cost, its quite simple. A heat pump operates at a COP between 3 and 4. This means it will move between 3-4kwh of heat for 1kwh electrical input. Thus if we want 15kw output, we need say a 5kw heat pump. But it also means we can easily calculate the cost of 1kwh of heat energy. if the electricity costs 30p/kwh, your 1kwh of heat output costs about 10p at a COP of 3, and ~7.5p if you get nearer 4. The exact operating point depends largely on outdoor temperature and humidity.

Gas currently costs about 7p/kwh. So at first glance gas is cheaper. The gap closes slightly when you consider that the boiler isnt 100% efficient and while manufacturers claim upwards of 95% the reality in a house that needs 70c water might be closer to 80%. the high figures are only achieved if the boiler can condense at maximum efficiency, which only happen when the water temperature is within a tight range. Just like a heat pump, if you retrofit a modern boiler to an old property that requires high flow temps, it wont condense properly and wont be as efficient as it could be.

So at 7p gas, 30p electric, you probably just about break even. At some points when the heatpump is running nearer a COP of 4, it'll be ahead, and at other points when its down near 3, and the boilers operating maximally efficient the gas will be slightly ahead. Its disingenuous to simply state the heat pump will cost £1.80 for every hour its on... My Gas boiler can peak at 38kw, so based on 7p gas it consumes £2.66 for every hour its on. But physics doesnt work like that. The heat input is equal to what comes out the other end. Wether its a gas boiler or a heat pump, the heat required to heat the home is the same. Neither system will run at full power continuously, they'll modulate their output to match what the radiators are extracting from the water. Thus the important figure is what it costs to produce that heat.

My AC systems have a COP of between 4.3 and 4.7 depending on the exact unit so we are talking roughly the same. I quote the following to potential customers for running costs based on my own energy tariffs:

Typical running costs for 2.5kW (7,000 Btu) based on electricity at 29p per kWh and 7.3p per kWh for gas
Electric fan heater or oil filled radiator approx 73p per hour
Gas boiler at 70% efficiency (10 years or over boiler) approx 26p per hour, at 90% efficiency (new modern boiler) approx 20p per hour
AC system approx 16p per hour.

Assuming a heat pump system working at a similar COP to an AC system, even initially it looks to be cheaper but all, except maybe the electric fan heater, will modulate the operation as required once the room(s) is up to the desired temperature. A gas boiler switches on and off whereas the heat pump and AC systems will slow down but the duty cycle will still reduce. How much of that is done will depend on the insulation properties of the building. If you are generating heat but then allowing it all to escape, the heat source will need to be on for longer. I installed an AC system in a garden office for a customer in January last year. He left it on 24/7 from the day I installed it until June and it worked out at 3p per hour according to his Smart meter. He was so happy he got me back to install another in his recently extended kitchen!

Digressing slightly but initially I was installing AC systems in garden offices, garage conversions and summer houses being used by people working from home as a result of lockdown restrictions. This is another advantage with them that they can be installed as a stand alone system in a location that can't easily be connected to the rest of the heating system. More recently, perhaps as a knock on from lockdown, many people have been building outdoor entertainment spaces in their garden. A larger summer house type construction but with a bar, TV, sofas, etc, a place for a party without taking over the house.

One advantage going electric is you can use time of use tarriffs, to shift some of that heating load. A friend of mine has a heat pump and an underfloor heating system. The pump runs over night off peak, consuming electricity at 7.5p/kwh and heats the floor slab. The slab then warms the house throughout the day. Clearly not an easy retrofit, but you can do similar with your hot water heating for example, using the heat pump off peak to heat the water tank. Some installations also have a large buffer tank for the heating, so again you can heat the tank cheaply overnight, and then pump the hot water out to the radiators when you need it.

But for how long will that situation exist? With the push towards everyone having a Smart meter, the energy suppliers can see when you are using the bulk of the energy. With more people using the cheaper 'off peak' tariffs to charge their EVs, run their heating, set their dishwasher and washing machine to run at night, etc, how long will it be before the daytime is off peak and the night time rates increase? My problem with Smart meters is that the push for them is that you can save on your costs. You can but only if you consciously do something about it. You can run around the house switching things off to save a few pence or you can say f*** it, I'd rather spend the extra and be comfortable.

The big problem i see currently is massively ripoff pricing. Heat pumps arent cheap, granted. A Gas boiler might cost a grand and a heatpumps more like 4-5 grand. The problem is the installers want to rip you off to the tune of 10 grand for an "easy" job, and or closer to 20grand for a "difficult" job. Clearly nonsense, even when compared to the already rip-off price a gas fitter charges to install a boiler.

Same everywhere though. My prices work out on average to roughly £8-900 per room for an AC system but I've had customers that have had quotes from other installers that are over twice that (and bear in mind I'm still making around £300 a day on a single install) for example, charging the customer full retail price for the units, so much for installation and a further charge for testing, commissioning and certification. They don't pay full retail for the units and the testing and commissioning is simply the final part of the installation as far as I am concerned. I suspect the heat pump suppliers are doing exactly the same.

My personal approach is pragmatic, i have a functioning gas boiler, and an older house thats needing redecorated top to bottom over the next few years. So as i decorate each room, i'll specify a new radiator which will correctly operate at a low flow temp and meet the heat requirements of each room. I'll also adjust any pipework as i go, to remove the microbore sections etc. This has two benefits, one it means i can run the gas boiler at a lower temperature, improving its efficiency, and secondly it means that a few years down the line, the house will be "ready" for a heat pump when the boiler expires.

And that is the way to do it. Adding insulation is another option that will reduce your costs in the long run. The differences in construction over the years mean some properties already have it but others will benefit greatly. I think I've found most of the different types while putting a 65mm hole in a wall for the pipework. Everything from solid walls without even an air gap, through to new builds with plasterboard, a 20mm air gap, 100mm thermalite blocks, 50mm of fibreglass and finally external brickwork (and even that is hollow). The worst I encountered was cavity wall insulation using polystyrene beads. Drill though one layer and end up with an avalanche of little white beads that go everywhere!

I'd go for Allmakes but, as you say, there's probably not a lot to choose. However, with poly bushes known to be worn out in a matter of months, they are definitely going to be better than them.

What makes you say they are NLA? https://www.lrdirect.com/anr3285-bush-rear-radius-chassis-end-ne, https://www.johncraddockltd.co.uk/anr3285-bush-rear-radius-arm-rr-95-02.html, etc

Admittedly not OE but still vastly superior to poly bushes.
,

Sloth did it on his see https://rangerovers.pub/topic/534-v8-electric-fan-conversion

There were reports a few years ago of the rivets holding the trailing arm to the end piece that bolts to the axle failing. The cure for that was to grind the heads off to get them out and replace them with stainless bolts. Never actually seen any that have been like it though. The other possibility is the bushes where the trailing arms bolt to the chassis.