OEM stands for Original Equipment Manufacturer so will, or at least should, have been made by the same company as made the original one. Britpart may be from the same supplier but sold to Britpart in bulk and sold through them or may be a cheap Chinese made copy, you never know.

There's a connector behind the LH kick panel that carries audio wiring. It's an 8 way plug and I think on a non-DSP system it just carries audio but may well carry other things on the DSP system. Got to be work a look.

The tank was originally see through, they go opaque with age so you can no longer see the coolant level through them.

That's what I did with the engine oil cooler as I figured they wouldn't come undone.

Drop the knee panel (4 screws), remove the instrument cluster surround (two screws at the top, two at the bottom that would have been obscured by the knee panel), unplug the petrol flap switch, unplug two connectors to the bottom of the instrument cluster, undo 4 screws that hold it in place (one in each corner, although no need to fully remove them just enough for the cluster to be loose), lift it out. DO NOT turn the ignition on while the cluster is unplugged. Temperature blend motor is the lower one of the two.

Does the temperature change at all or is it stuck at one setting? You say driver's side UK but then talk about the glove box which would be on the UK passenger side so what is your car, left or right hand drive? If RHD, you can get at it by taking the instrument panel out and going in through the hole, if LHD you can get at it by dropping the glove box. You don't necessarily need to calibrate it but if you don't you may find that with the temperature set the same on both sides one side will be warmer than the other.

DavidAll wrote:

The pipe from the gearbox to the left side of the oil cooler on the manual v8 had seized so I needed a new cooler and pipe. I don't know why but the left hand thread on the cooler takes a 27mm nut and the right hand takes a 24mm nut

I initially read it as the 'left hand thread' meaning the thread was left handed then realised David was talking about the thread on the left hand side. So no, the threads are standard right hand thread, just a different size from side to side.

Usual cause is the tailgate seal but water getting INSIDE the lower tailgate?

It connects to a switch on the clutch pedal to shut off the cruise control on a manual gearbox version.

Spare wheel well filling up is usually tailgate seal or rainwater getting in around the rear light seals. About the only place water can get inside the lower tailgate would also be around the rear light seals for the additional light clusters on the tailgate. Maybe someone has taken the lights off in the past and put them back without the seals?

I assume it's the same on a Disco but on a P38 you can take the rear door off and cut through the loop that the latch striker hooks around. Someone made up a tool for doing it using a steel tube with the end of it shaped to fit over the loop then use a drill down the centre of the tube. That stops it slipping off while trying to get the drill started.

is it the relay or the socket? The terminal for the input from the engine ECU went intermittent on my old fusebox so as a work around I poked a wire in the hole and jumpered it to an ignition switched supply until I replaced the fusebox. The old one had already been pulled apart and repaired not long after I got the car so figured it deserved a brand new one. I normally use these https://www.autoelectricsupplies.co.uk/product/169/category/36 and get the ones with the diode. Rated at 40A so better than OE which are only 30A. For replacements for the 5 pin changeover ones, these https://www.autoelectricsupplies.co.uk/product/174/category/36.

But I cruise at 75-80, even with a trailer!! Did you wind it up to the red line?

Agree totally. Mine seems to get smoother and more powerful after the first 30-40 miles so they do need a good thrashing every so often. Seen 105 on the sat nav on mine (showing 106 on the calibrated speedo) once on a long gentle downhill in Germany. Decided it probably wasn't such a good idea and backed off as I had a trailer on the back loaded with two keyboards and a 12 piece drumkit......

Whether there is any truth in it I've no idea (although it could adjust the adaptive values for WOT) but you've got a Sport button, so use it. Always entertaining to poke the button, floor the throttle and watch the tacho run up to 5.5k before the gearbox changes up. Makes you wonder how something with the aerodynamics of a small bungalow can accelerate that fast......

That makes perfect sense. As you say, even though the engine had stopped firing it was still connected and the pump and torque converter was still turning. So my thinking was right, if the engine isn't turning the pump won't be so there's no drive so it isn't possible to tow start an auto, no matter how fast it is moving. I'll carry on keeping a spare starter motor in the boot when I disappear off to the Continent......

So you can tow start an auto if you go fast enough? My understanding was that as the pump isn't turning there's no drive from gearbox output to input.

There's pressurising and over pressurising. When the engine gets hot the coolant expands so the system pressurises. When it cools down again, the pressure is gone. However, if combustion pressure is getting into the cooling system, it will pressurise when hot and remain so when it cools downs. That's your easy check, remove the coolant header tank cap and put it back on to ensure there is no residual pressure in there, squeeze the top hose to confirm no pressure, run it to normal temperature, squeeze the top hose to confirm it is pressurised, switch off and leave the car overnight. By morning, the top hose should be as it was before you started the engine.

If it still has pressure in it, you are getting pressurisation so take the spark plugs out and look at them. If any are cleaner than the others, they are being steam cleaned by coolant. If it is any of the end cylinders (numbers 1, 2, 7 and 8), it is head gasket, if any of the middle ones, it is leaking around a liner. In which case, the stuff you linked to will cure it. However, the active ingredient in Steel Seal is Sodium Silicate, also known as Water Glass and it's much cheaper to buy it without the pretty green dye https://www.ebay.co.uk/itm/Sodium-silicate-Water-Glass-500-ml-Free-Post-in-UK/264718636840

Airtex, Airtex or Airtex, that's the only pump to fit. I wouldn't fit anything from Britpart that critical.

Unless it's new, I would say water pump, but there are a couple of bolts that go through the water jacket and people have suggested coating them with RTV when putting them in.