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I haven't looked into what any of them actually contain - but it won't be r134a, and some even state as such its a 'compatible gas' - if it works, then great.

Changing the drier is like changing the filter when you do an oil change... you can leave the old one on and it'll run fine, but it won't do the job like it used to. Aluminium oxidises and corrodes, and most a/c systems are made up of a lot of it. So over time you have the risk of internal corrosion floating around and blocking the TXV etc. That said... I haven't always changed it, and I haven't had a problem. On my E60 530d, the drier is actually part of the condenser... presumably for cost and space saving reasons - but it means when it inevitably gets stone holed and needs replacing, you get a new drier automatically too. On the other hand, I had one of the discharge pipes rub through on body work and vent the precious gas :( I replaced the pipe, vacced down and had it filled - I'm not changing the whole condenser because of that... Sure, it won't work as well as a drying agent, but I left it vacuuming for hours to hopefully boil off some of the moisture the desiccant would have absorbed.

The trouble is with places charging a flat rate of say £50/fill regardless of car, is that most cars take 6-700g... then we rock up with a P38 needing 1200-1380g. Suddenly they're barely making any money taking cost of gas and their time into account. At the same time... that's not my problem.

The DIY refill things I'm not a massive fan of because in the UK, they can't legally contain actual refrigerant anymore. So long as the pressure on the low side doesn't end up massively high, it should be okay. But it can't beat weighing it in. Equally.. if the system is empty and has air in it, you're filling a system with an unknown 'refrigerant' as well as the air, which will have moisture in it and emulsify the oil... all ending in a mess. Pressures probably all over the place too. Then you have those with 'stop leak' additives in, which I've seen quite a lot of stories of TXVs being blocked up as a result, needing evaporators pulling out to replace etc.

I'm not sure on the R12 idea - I believe propane is mostly compatible in properties with R22, and R290 is basically just propane with a very low moisture content. Just has the slight downside of the old flammability issue... although the new R1234YF is too, so I guess car manufacturers aren't that bothered. I know a lot of us drive around with LPG plumbed up all over the place, but to me you're much more likely to end up with a big leak on a condenser when a nice pointy stone hits it or you have a collision with something in front....

Doesn't sound like they know what they're doing. The machine will have gauges on it - I've never seen an automated machine with no indication of actual pressures even if they are meant to be idiot proof.

There won't be any power to the compressor clutch when there is no gas in the system - as the trinary switch low pressure cut off prevents the clutch engaging by breaking the circuit, to prevent the compressor engaging with no gas to move oil about the system and causing damage. It's wired in-line with the clutch, so it won't report back to the HEVAC or log any codes etc because the gas as escaped*. Chances are, its got no gas, or if it has, the trinary switch has perhaps failed.

I'd go somewhere else to start with - if they don't know why their was no power to the clutch without checking pressures, they haven't got a clue.

I can dig out the trinary switch pins to bridge if you want to check the clutch for operation etc.

*One exception - on early P38s, the HEVAC provided power to the clutch (through the trinary switch) directly, so if the system was low on gas/empty and the low pressure cut off was activated, the circuit was broken to the clutch. Because the HEVAC on these earlier models could 'see' the load/current draw of the A/C clutch, it could detect if the load was missing and throw an 'open circuit' fault on the compressor output. When this changed to drive via a relay, which draws much lower current, the error detection was programmed out. Yours will drive via a relay, and thus the error detection won't be present. Unless of course someone has swapped in an early HEVAC controller for some reason - in which case you'll find the open circuit fault for the compressor output with a nanocom. This aside, gas or no gas, correct or incorrect HEVAC, take it somewhere else.

Oh one more thing - as I'm not F Gas certified yet I had to have my RR filled up by someone else recently after the condenser leaked. I took it to my local F1 autocentre. Picked it up and was told 'oh, we've underfilled it a bit because its an older car and its a lot of strain'. For the price, I wasn't too fussed at first. But then I realised, the 1000 out of 1380 grams the Thor setup is meant to take is quite a chunk missing... and it was hissing in the evaporator really obviously, as they do when low on gas. Made them fill it properly, because frankly, the 'strain' is bullshit, and I've paid to have it filled.

The guy gave me the receipt that the machine printed out for a second recovery and refill operation... which I don't think he realised showed what it extracted - 627g. Not even close to the '1000' he supposedly put in. I know r134a is getting expensive, but I don't give a toss - I've paid to have it filled and to work properly.

The p38 takes a lot of refrigerant - if the place you go to doesn't specify that they charge by volume/weight, make sure they fill it properly and don't try to screw you over.

The nitrogen will pressurise the whole system - if the compressor was 100% gas tight between its pistons/vanes/whatever type it is, the gas would just go the other way around the system back through the expansion valve in the evaporator.

That's assuming only one side has been connected up to their manifold - if both sides are connected up and opened then you're pressurising high and low sides from the manifold.

I've got a few bottles of nitrogen and all the kit to test and evacuate my own systems, but unfortunately my high pressure nitrogen regulator needs a few bits to make it usable that I haven't got yet.

I think I've mentioned before, but on a P38, the obvious culprit for leaking badly is the top corner of the condenser where the foam blocks retain water and accelerate corrosion. The second place is the suction (big) pipe on the firewall where its pressed against the foam. When its running the suction line gets cold and sweats. Condensation is soaked up by the firewall foam and slowly pin holes the rear side of the pipe. Problem is, even with UV dye in the oil, its not obvious, as said small amount of dye that makes it out also ends up in the foam. Soapy water around that area while pumped up with nitrogen is the best way to check.

Coolant temp sensor can stop a Thor starting - mine was intermittently shorting out reading far too hot (140 odd c), and wouldn't start. If its gone the opposite way, it could possibly be overfuelling and messing with timing so much it won't start in this ambient temperature.

Just a thought - do you have a nanocom or OBD2 device to check engine data?

When you go through the head unit's audio options, do you have a DSP setting? Assuming it has the stock Alpine head unit it should have shipped with.

Failing that, behind the trim in the load space on the left side, if you have DSP, there will be a single large amplifier. If no amplifier, it either has door amps, or is driving the speakers directly from the head unit - which was only really found on more basic models (including the Bordeaux weirdly).

The drier should really have been replaced with a new sealed unit really, as it contains desiccant to absorb any moisture that manages to get into the system. If its holding gas okay at the moment, I wouldn't go rushing to change it - but if you do ever have to have it emptied/refilled in the future, it wouldn't be a bad idea to get a new Nissens part on it with new o-rings.

The nanocom doesn't show the request status, but the HEVAC itself should be requesting the compressor when the evaporator temperature is anywhere about about 7 degrees C. It cools the evap down to about 3, then shuts off, and requests again once it reaches 7. Assuming 'AC Off' isn't pressed. Temperature selection shouldn't matter, as the air is cooled and then re-heated by the heater core. When its set to 'hi' on both sides, it might disable the a/c, I haven't tested that.

When ambient is below 4-5c though, it doesn't request it. Consider it this way - if its only cooling the air coming in to between 3 and 7c, there isn't much it can do when its already cold outside. It just risks freezing the evaporator up.

It's entirely possible it is taking the heater core temperature into account too - I haven't come across a core sensor showing an erroneously low reading myself, at least not on a car with working air conditioning.

Do you have a multimeter to hand? You could check the request output and grant input on the HEVAC itself to see what is going on. Probably worth sorting that heater core sensor first though.

"Compressor open circuit" suggests your vehicle is one that drives the compressor clutch directly. This was changed to drive via a relay (and that fault detection/message was programmed out), as the direct feed from the HEVAC controller through all of the connections and loom wasn't always man enough to pull the clutch in. If its working, then its a non-issue currently.

The fault would also come up when the system was low on gas - the safety cut off switch is wired in series to the compressor clutch. When the gas pressure drops too low, it cuts off the feed to the clutch, and thus the directly-driven setup would detect open circuit.

I don't believe so - straight to the becm. It only brings up the message - it doesn't actually change the operation of gearbox or engine at all. Just a warning really.

Welcome :)

Hopefully your existing poly bushes come out with less of a fight!

Post up your air con issue and if I can be of help I'll chime in :)

Gearbox overheat is usually the sensor on the cooler failing. The sensor goes open circuit when it reaches the predefined 'I'm too hot' temperature - I don't know what it is off the top of my head.

Anyway - they fail quite regularly. Mine is intermittently dodgy, claiming overheat at random (even when cold), so it is unplugged and I've bridged the terminals of the plug until I get a replacement.

You might be lucky and its the sensor at fault... or one of your ratty friends has chewed through the wiring, and its now open circuit... thus bringing up the fault. I highly doubt low battery voltage would bring up just gearbox overheat and show no other signs of low voltage. Gearbox fault on the other hand, IS a common sign of low battery voltage.

Repair the wiring or replace the sensor (whichever appears to be at fault, short the plug on the vehicle side of the loom to test), and the message will go away - nothing needs resetting.

On a V8, the cooler can just about be seen down the side of the gearbox cooler. The plug for the sensor is blue and on leads.

They're also used extensively in electric wheelchairs.

Speaking of which, a friend of mine builds and maintains them - so conveniently I have a source of good quality lead acid batteries direct from his supplier. Lucas isn't on that list of decent batteries - given they just slap their name on someone else's battery of unknown quality.

Not keeping them charged is the user's problem so far as I'm concerned. It's like a torch.. a device used for storing dead batteries ;)

As for using a bigger battery - that's fine, but the bigger it is, the less convenient it ends up being. Always a trade off. I have a spare 88ah battery that kicks around being used and abused. Even in the back of the RR, it isn't s small or light thing to push to one side.

Let's look at the MF31 battery for a second, that puts out 1000 cranking amps, we all know it well here. It's a big heavy beast.

Expecting that from something portable, lightweight or reliable isn't in my opinion reasonable. Sure, lithium can do it. But reliably and safely in a small package?

Jump packs exist to give the vehicle battery a boost. Connecting one up to a completely dead vehicle battery probably won't be that successful, firstly because you're dumping current straight into that dead battery.

Considering most of the cheap crap SLA ones have a single 10 or 14ah battery in them, I'd say 42ah or the 44 as mine has is pretty good. Also quite a bit bigger than you'll find on a moped I'm sure...

But none will be as good a match as decent jump leads, connected to a running vehicle supplying essentially endless current to charge the dead battery.

I'd much rather have one of the 'traditional' types with one or two SLA batteries in it. A decent one mind, not the crap from Maplin, Argos or halfords. Sure they're big and heavy, but far less likely to suffer thermal runaway and explode than a highly strung lithium pack being asked far too much of.

Machinemart sell a range of decent SLA based ones. I have both their old 900, which is a single 18ah battery, and the 12/24v one which is a pair of 22ah batteries. On 12v, you get 44ah of power as they're wired in series through the selector switch.

Ah but you're forgetting Rutland here is quite the radius arm whisperer!

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Good news on getting some replacements sent out though. As/when it comes to needing to do mine I think I might get a couple spare, just in case.

The only time I've used polybushes (or a variation thereof) was on my E39. The rear trailing arms have pressed bushes that aren't (or weren't, it has been a while) available separately, and the arms costs somewhere in the region of £500. EACH.

Set of polybushes from some supplier in Europe specifically for these arms on the other hand was something like £80 I think. Even if they needed replacing every 2-3 years, it would have taken quite some time to justify spending a grand on two arms.

Aha, mmm at this point the mount to the left in that picture would need a 3" diameter hole cut out of the bodywork and new metal welded in if I wanted to mount tie downs :(

Which I might do in the future.

Nice - are they using the rivnuts/captive nuts already present in the floor? On discovering my water ingress problem, all of mine look to be salvageable :(

...next time I'll bring the blow torch. Can't argue if its a liquid. And we'd have had the BBQ going one way or another ;)

Good to meet some new people :)

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And the mysterious case of the non-functional blend motor:

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Rutland show's off his balancing act:

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And finally we've optimised the process of oil changes with the revolutionary bulk lubricant vessel filling utility, aka: the batten and tap.

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Above the marker is close enough. This should be removed once you all know where you're going really :)

I'll be there probably quite early as will Marty I suspect - so look out for a collection of P38s, you won't be able to miss them.