Hello all,

 

I have a 2013 Superb MK II (CFFB engine) with 80k miles on it. The AC has suddenly stopped working with no warning. When the AC is selected on there is no hint of a change in engine load & (from what I remember) no quiet click from a relay engaging. There is no temperature change in the air coming from the vents regardless of the temperature selected on the climate control. I’ve checked the fuse (located between steering wheel & drivers door). I’ve run a OBD scan with no faults found. 

 

My question is where do I go from here? Should I consider checking any sensors (I’ve seen mention of temperature & pressure sensors), try a re-gassing or presume its a compressor failure? I’ve had a quick look at the engine bay but cant see anything immediately obvious.

 

In the meantime should I avoid driving the car to prevent further damage?

 

Thanks for any info,

 

 

Hi, if you are not seeing a change in engine load or a click from a relay, I would suggest your compressor has broken. I am no expert mind, but that would be my first port of call. A local independent should be able to change it for about £400.

Compressor common fault. 

Are the fans/is the fan working? Not the blower motor but the rad fan.

Thanks for the messages. I'll have to check the rad fans & get back to you.

 

I was onto a garage here in Dublin, €500 for parts & labour for used part, €1000 for genuine new.

 

Is it even worth thinking about changing as a DIY job (gas vacuuming/ re-gas aside)? I've done a bit of work on cars but no specialist tools.

 

Thanks again

Check if the fans are working, if not then preferably get a VCDS scan or if not get someone to measure the low side pressure with an A/C manifold set, if pressure below the threshold but not zero then its a recharge you need, if zero pressure then you have to find the leak, common suspects are the drier tube if its integrated into the compressor or the high side pressure sensor (G65?) and if you are lucky you will see signs of leakage and/or the sensor body split from corrosion. both are easy DIY jobs.

 

Before playing parts bingo with the compressor just because someone on a forum says its likely to be that get a VCDS hooked up and look for the A/C shut down code if present, this will tell you if its not wrking due to the failure of another sensor, low system pressure, fan failure etc.

 

If no shut down code then its likely to be the A/C modulating valve at the rear of the compressor N something or other, cant recall the code, another easy DIY job, cheap to replace, much cheaper than a compressor but it will cost you a recharge to see if it has worked or not, I have had at least one faulty one from E-bay and paying more does not guarantee better qulaity or that it will work, I bench test them first now.

 

Finally a compressor replacement is another easy DIY job or at least it is to me but will again cost you a recharge.

 

If replacing the valve or compressor if the system has pressure then get a garage to vacuum off the refrigerant, they will probably do it FOC if you agree to have them do the recharge because then they will be selling your refrigerant back to you

Many thanks indeed for the reply.

 

I've just run the car from cold & the fans are not running. I'll try again when warm to confirm. I should be able to get a VCDS scan do & take it from there.

 

Thanks again, will keep you updated

Perhaps I've found the problem, a VCDS scan shows the following:

 

Quote

9474417 - Motor for Front Air Distribution Flap  
          B1091 71 [008] - Actuator stuck
          Intermittent - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 2
                    Fault Frequency: 1
                    Reset counter: 68
                    Mileage: 129560 km
                    Date: 2020.08.02
                    Time: 11:17:19

 

 

Would this be enough to cause the AC to pack up? I've reset it & will see if I get any joy..

4 minutes ago, leo837 said:

Perhaps I've found the problem, a VCDS scan shows the following:

 

 

Would this be enough to cause the AC to pack up? I've reset it & will see if I get any joy..

 

 

Just noticed that the date looks like when the issue began..

Looks like that hasn't fixed the a/c so now suspecting the modulating valve.

 

Going to have a look today or tomorrow but has anyone changed one on the car without removal of the compressor (following degas of course)? Is there a way to confirm a faulty valve based on electrical resistance across terminals or applying 12v to see if theres a lack of a 'click'

 

If anyone has a part number it would be great also (CFFB engine).

 

Thanks,

Yes I have removed in situ.

 

No I doubt that you would feel a click in situ, even on the bench you can feel the clicks but its difficult to see any difference between a good and a bad valve.

 

Is your flap valve operational again? I would test it using output tests in VCDS.

 

If you have sufficient system pressure, no compressor shut down code, if the N285 valve is being commanded but there is no subsequent rise in the high side pressure then you can suspect the valve as a cheapish try out before having to change the compressor but the costs of regassing does not make it cheap unless it was the valve.

 

A broken shear plate on the pulley or the central nut coming loose and/or the inner bub splines stripping will give the same results as above, best to check them with a mirror and light while the aircon is supposed to be running, the central nut should be rotating at pulley speed.

8 hours ago, J.R. said:

A broken shear plate on the pulley or the central nut coming loose and/or the inner bub splines stripping will give the same results as above, best to check them with a mirror and light while the aircon is supposed to be running, the central nut should be rotating at pulley speed.

 

Well that could certainly be the issue! I had a look at the compressor again & the centre bolts & fixtures are stationary (no rotation whatsoever) while the pulley is in motion. I've attached a photo, hopefully you can see what I mean. The AC was selected on when the photo was taken.

 

It looks like this may be a replacement part . And it's been mentioned before on this forum

 

Looks like I'll need a puller but hopefully won't need to work about degas etc..

Edited 20 August, 20205 yr by leo837

No puller needed but if the shear plates have broken then the pump is likely to have grenaded, squeeze in with a 13mm spanner and try to turn the pump shaft before ordering the part.

Half the price here:

 

https://www.ebay.co.uk/itm/COMPONENTS-OF-THE-COMPRESSOR-AIR-CONDITIONING-COMPRESSOR-THERMOTEC-KTT020055/293204553912?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

JR,

 

Thanks again for the replies. I'll give the compressor a check tomorrow & see how it goes..

 

It  seems that ebay part is fairly different, I think there are different clutches around. Do you think its compatible?

There are several different makes of compressor fitted & all have different drives.

 

Have a look at my old post where my compressor drive was rattling but still working.

Replacement drives are now available on eBay https://www.ebay.co.uk/itm/A-C-CLUTCH-DISK-DELPHI-DH5-SKODA-OCTAVIA-SUPERB/392275299499?hash=item5b556e0cab:g:e2cAAOSwnO5cruv3

 

But it does sound like your compressor may be goosed, which caused the drive to fail as it is supposed to if the compressor seizes in some way.

Thanks for the info. I just tried turning the centre nut on the compressor & it turns freely so I assume I've been (somewhat) lucky.

 

Having a quick looks it looks possible to change in situ via the wheel arch. I see you mention use a puller to get the clutch disk off. How does it reattach? Are the three legs press fitted into the pulley?

 

Many thanks

The coupling I linked to is for the Sanden PX16 compressor, no puller is needed, the centre bolt needs removing which will be a challenge with it rotating freely, take your time & think it through, I bent the shaft on my MK1 Octavia replacing the E/M clutch assembly and was without AC for 10 years before fitting a second hand compressor.

 

Once the centre nut is removed then the coupling is held on by 3 torx screws.

 

If access is too tight its only 3 bolts to release the compressor and move it on the flexible hoses to a better position and not hard to do, if you do it in situ you dont even need to remove the aux drive belt.

Editted, yours looks like the Delphi compressor as that looks more like a bolt than a nut.

 

You should be able to read the identification label with the VAG part number from underneath or with a mirror on a stick to confirm the compressor.

 

I have the same Sanden PX16 units on my Yeti and the now sold Octavia 2

Many thanks for the info.

 

Is there a better retrofit pulley/clutch setup available? This doesn't seem like a great design & I dont want to be doing this again in a year or two.

The pulley linkage is designed to fail if the compressor seizes to avoid having the auxiliary belt getting mangled and stopping the water pump too. It means that the pulley linkage will eventually break anyway from the wear and tear of starting and stopping the compressor over time.

 

I had to change this on my Superb last year for the same reason (different compressor though and different pulley design). There's room to get at it from inside the wheelarch once you remove the plastic liner. You'll need something to counter hold the pulley while you loosen the nut/bolt. The pulley should come off easily enough.

Interestingly whilst that shear plate is a different construction to the one in my link which fits my two compressors both of their part numbers are listed in the advert for the other shear plate so I believe that they might be interchangeable.

 

Or perhaps the complete Delphi and Sanden compressors are interchangeable and carry the same VAG part numbers but the individual parts are different.

 

I think my hub would fit with minimal adaption unless they use different splines, it is of a lighter construction which is an advantage because there is less inertia and its the constantly reversing acceleration/deceleration forces that can destroy couplings like this.

 

Looking at the mass of that one and reading of the rivets becoming loose I can easily believe that they could fail when the compressor is in perfect working order.

Edited 21 August, 20205 yr by J.R.

20 hours ago, leo837 said:

Thanks for the info. I just tried turning the centre nut on the compressor & it turns freely so I assume I've been (somewhat) lucky.

 

Having a quick looks it looks possible to change in situ via the wheel arch. I see you mention use a puller to get the clutch disk off. How does it reattach? Are the three legs press fitted into the pulley?

 

Many thanks

Undo the centre bolt & the 3 leg coupling will just pull off the splines.

 

Once that is out of the way you will see a circlip that holds the pulley on.

Remove the circlip, take the tension off the drive belt & the pulley will also just pull off.

 

You will see there are 3 special bolts on the pulley with dimples in the heads that the 3 leg drive fit into.

 

If the compressor is ok, they must have worn.

 

You could loosen them & rotate 180 degrees to get another life out of them or buy replacements if available.

You will also need the new 3 leg coupling.

Just remembered that I found two hex bolts sitting on the driveway about 3 weeks ago. Its obvious now where they cam from. I probably change both pulley clutch to be safe.

 

 

The nut heads that should be on the other ends have the dimples in them.

 

Looks like they all came loose & just fell apart.

 

You may just need new screws & dimpled nuts then if they are available. ( & some Loctite )