19 minutes ago, J.R. said:

I am not wasting my time because I am not trying to get the aircon to work at 2°c but to find out why it has not been working at normal temperatures, far from wasting my time thanks to advice on this forum I have learned a lot today and for the first time feel that i may be getting closer to the real problem which looks like it might be the evaporator temperature sensor.

 

I have found now that the evaporator is inside the cabin, part of the heater/climatronic unit, as such it should be at the same temp as the interior vehicle temp and not 6° beneath it, I can understand now what you were asking me about does the temp come up if I use the heater, in fact I am going to brave the cold and start the car and let the heater do its job for an hour before doing another VCDS test.

 

I amjust going outside now, i may be some time........................;

 

My point is that you can’t fault find properly if the car is inhibiting the air con compressor but if you must persist....

 

 If you warm the evap temp sensor up it should at least take that out of the equation and you might see the compressor want to run unless the ambient air temp is tied into it which I don’t know for sure

 

The heater matrix is after the evaporator so that won’t make any difference you will either have to physically take the sensor out and warm it up to 20-30C. That way the compressor should want to run at a decent load but it will freeze up if you leave it too long. 

 

 

38 minutes ago, J.R. said:

I have found now that the evaporator is inside the cabin, part of the heater/climatronic unit, as such it should be at the same temp as the interior vehicle temp and not 6° beneath it, 

 

The evap temp has nothing to do with the interior temp, the load of the compressor is controlled by this temperature. In most circumstances the ideal evap temp should be as cold as possible but above freezing temperature. This is what dehumidifies the car. This is also why if your trying to run the air con and its lower than 5 degrees outside the compressor will not run as its getting down to that temperature in which it would freeze solid and not let any air pass through it.

 

You could turn the heater up to the max and the climatronic should still be asking for that evaporator to be cooled down.

 

Hopefully my ramblings will make some sense!

Edited 30 January, 20197 yr by SuperbTWM

Evaporator is indide cabin, but nearest the outside world in terms of airflow. So if no cooling is coming from the A/C it will be somewhere between external and cabin temp, depending on fan speed/airflow into cabin.

Yes they make sense after I have been out for another play, the shut down code 8 was for outside air temp, its currently 0.5°c so I understand and agree that i am wasting my time at the moment aside from learning and knowing what to look at when things warm up.

 

Heated the cabin right up and the evaporator temperature rose to 7°, cant recall what I said it was before but i saw it rise through a couple of degrees so the sensor appears to be working.

 

If as you say the evaporator is intended to be cold then it will I guess be insulated from the cabin temp so the 7° appears plausible. Will leave till warmer weather.

 

One interesting thing, ran the car with heater on HI for a few miles, temp guage up to the middle 90°c I think, sitting with the engine idling and the heater on the temp guage dropped to 1/4 and VCDS showed the coolant temp as 63°c so in freezing conditions the engine does not give out enough heat for the heater demand.

If you warm the cabin up and put it in re circulation mode set the vents to footwell (where the intake is), that is one way to warm the evaporator up.

 

Glad you have seen sense, will be a lot easier to prove the system once it gets warmer

 

 

Edited 30 January, 20197 yr by SuperbTWM

Your posting overlapped Wino, yes that makes sense and my readings are plausible.

 

Will need to wait for warmer weather but at least I know what I am looking for now and for the first time am confident that I will be able to diagnose the real fault.

 

TBH I hope its not the evaporator sensor and it is a new AC pump needed, the evap sensor is a dash out job and would mean that I wasted my time and money on the compressor control valve and regas when I could have found the fault if I knew what VCDS could have done for me.

 

2 other bits of what might be relevant info, when I bought the car it had what was reported on the MOT as a broken engine mounting, new cylinder block needed it turned out to be the alloy casting that holds the AC pump and alternator, to replace it meant unbolting and leaving the aircon pump hanging, perhaps this caused the problem independant of the G65 sensor.

 

secondly air blows out of the LH central face level vents but not the right one, I have had the unit in and out a few times to pass the cable for my shatnav, ther has also always been V71 airflow flap positioning motor fault codes.

Are you sure the sensor is a dash out job? Its not on a RHD car anyway, just the glove box needs to come out 

No and happy to hear that, it was from googling that often led back to this site.

I got to test it when the outside temp was above 4°c, zero for the shut down code, the valve was being commanded to open, both voltage and current seemed plausible but still no cooling so I bit the bullet and ordered a new compressor.

 

found one for what seemed to be a bargain price on E-bay but now that the details are finally revealed I expect I will get what I paid for

 

It was a listing on Ebay France supposedly from a seller in Portsmouth UK, listing was partially in French but mainly English, seller had no listing on Ebay.uk or anything else listed there, price was too good to be true at €140 = £122 including free delivery to France that didn't sit right, within the UK maybe but not to Europe.

 

Looking at the detail on the confirmation E-mail which was not shown anywhere on the listing Portsmouth now appears to be in China

 

atoptuning-fr (497)

99% positive Feedback

Jihua Road, Bantian Street, Longgang District Shenzhen, 广东省, 518129 China   This is not the first time that this has happened to me.

Oh dear  I guess £122 isn't too much of a gamble

 

So when you got the compressor to run, what was the evap sensor saying?

It didnt drop in temperature at all when switched to 'LO" I was able to use advanced measuring blocks or whatever it is called to look at several parameters, the outside temp was 4°c and set to "LO" the air coming out of the vents was 10°c.

 

It was interesting to look at the temp of all the vents during heating and to see just how much work the Climatronic does.

 

As you say a great price for the pump, if it works..........

 

If it doesnt I will have wasted 2 times €59 on regassing plus the price of the pump.

 

All of my brake discs, pads, backplates etc came from Autoteile in Germany and they were all made in China as are probably most of the brand name pumps so it could be alright.

 

Looking forward to dismantling the old one to see whats what, I reckon it will be something very simple and nothing worn, I am gambling on that as I wont be changing the condensor.

I would change the dryer unit as well while your at it, and make sure you have the correct 'O' rings if you don't already, the dealer is probably to best place for those.

52 minutes ago, J.R. said:

dismantling the old one to see whats what

I'm looking forward to that too, I do love a teardown.

Wouldn't worry me particularly to have a Chinese made replacement part on its way.

 

Me neither, most of the stuff is very good, sometimes needing a little fettling, trouble with aircon is the cost of regassing to find there is a simple thing to redo like seat an o ring.

 

I will strip the old one on removal and might do the same to the new one before fitting!

I've found this guy to be very good, do check out all his vids.

 

Mostly on a Golf Mk5 but same same.

 

 

Fascinating, shame he didn't open up the other end where if mine has a problem I suspect it will be.

 

There could have been a big clue right at the start, mine does not have the plastic cap over the nut but I can see the shear plates are intact and the nut turns with the pulley when engine running so am fairly sure the shaft is turning.

 

€140 is getting me a lot of precision engineering plus a door to door delivery half way around the world, how much would that have cost 30 years ago for my first ever vehicle with aircon?

Compressor arrived today which was a surprise because only yesterday Ebay advised that it had been despatched from China and said that it would take a further 30-50 days to arrive! funny how a listing that shows a UK seller with one week delivery always turns out that way isn't it but in this case it came really fast and given that the bargain price included "free delivery" and the parcel weighed 5.7kg came half way round the world and was put in my boîte à lettres I am not complaining.

 

It feels dry when I turn it as if there is little or no lubricant but maybe its just the newness or lack of manufacturing tolerances, removed one hose fitting blanking cap and nothing inside, removed the other (the HP side)  and there was an inrush of air, it was under a partial vaccuum and I can see some traces of yellow fluid.

 

I am really not sure how far I could drive with it to get it recharged, any suggestions?

I would want to get somebody mobile, unless you are confident that there is sufficient lubrication inside that running it will not cause it to seize up.

 

I would think it would have been tested by traces of fluid inside so it might be ok.

 

Or from the looks of that video if you take the front plate off that drives the shaft from the pulley you could actually drive the car with the aux. belt on without turning the compressor. Then re-install the drive plate when you get to somewhere to recharge.

Edited 8 February, 20197 yr by SuperbTWM

Or you can do what I did, get a shorter alternator belt, it only drives the alternator not the A/C compressor.

 

You might need to change the condenser too, as the drier pack is part of it depending what type you have, and the modus type you cannot get the drier pack even from the stealers.

 

 

 

 

Trev

Edited 8 February, 20197 yr by Aston_Bodger
Missed info

Mobile aircon guy a good idea, not here in business unfriendly France, it wont exist but I will soon be back in UK and will do the swapout in my workshop.

 

The prize though goes to Aston Bodger with the shorter belt drive, it would make a good spare to carry afterwards.

 

I will enquire into sourcing a condensor drier.

 

Thanks for all the responses, what started as a simple job has become a misssion but my determination only increases and its good to gain knowledge each time.

If you are doing it yourself and handy with the spanners will take you about 3.5 hours.

 

 

Trev

You have to be kidding, 1 hour maximum and that at a snails pace unless the pipe couplings have some unseen difficulty.

 

I have already removed it once to replace the alloy mounting bracket that it shares with the alternator.

 

Would be even quicker if I had a ramp.

 

6torx screws for the undertray, spanner on tensioner lug to remove drive belt, pull off electrical connector, undo flexible pipes (unknown) remove 3 bolts and out it comes, reverse procedure for new one.

 

What have I missed?

 

Editted, OK will be a little longer if I replace the drier.

Edited 9 February, 20197 yr by J.R.

That's just the A/C compressor, but the manufacturer of the compressors recommend you change the drier too, it's no longer available if you have the condenser with the plastic nut at the top right corner as you look at it, that's why I said it was a3.5 hour job to do the condenser the whole front end has to come off.

 

 

Trev

Thanks Trev, just looked, mine looks to be the integral one so it will have to stay.

@J.R. If you ant to go down the shorter belt route, here is the part number, 03G 903 137 A

 

Trev