Air con problem.

[phazed]

 I have just bought a lovely MK1 and the only problem that I can see is the air-conditioning is not working properly.

The car has been generally unused for five years but has been regularly taken out and driven a couple of miles every few weeks so I very much doubt if the Aircon has been used.

 

It seems that when you switch it on the air temperature lowers by only a couple of  degrees but no more.

 

I took it to a local reputable garage yesterday and had the system re-gassed. They did say it was very low but was up to specification now. This hasn’t made any difference.

 

I can rebuild engines but my air-conditioning knowledge is woefully Very thin on the ground!

 

The air conditioning pump kicks in when the system is switched on and that’s about it.

 

 My son, ( mechanic, Nissan trained!) put on his diagnostic kit and it isn’t showing up any faults.

 

Any pointers would be appreciated.

[KenONeill]

@phazed - Is the pump shaft (not the pulley) rotating when you select "Auto" on the Climatronic controls? If not, then investigate the fuses and suspect a problem with the air con pump clutch.

[phazed]

Yes, the pulley locks on and rotates when selecting auto.

 

 Just had a check with my cheap digital thermometer.

Center vents started out at about 24°.

Engaged auto and set  temperature to minimum and it dropped briefly to 19° and then started climbing again to about 28°! 

 

 From memory, when you engage auto and the air-conditioning is on there is usually a frost star on the display isn't there? There isn't anything indicating that the AC is on when you engage auto on the display.

 

 Searching for the handbook in the owners wallet and everything is there apart from the handbook! 

[Ttaskmaster]

18 minutes ago, phazed said:

Engaged auto and set  temperature to minimum and it dropped briefly to 19° and then started climbing again to about 28°! 

 

 From memory, when you engage auto and the air-conditioning is on there is usually a frost star on the display isn't there? There isn't anything indicating that the AC is on when you engage auto on the display.

Does the compressor cut out when you give it some revs?

I'm facing a similar issue with mine - Kicks in when you start up and blows vaguely cooler air through briefly, but drops off the moment you add 1 single extra RPM.

I'm ordering a new compressor soon as I can!!

 

Nope: http://archive.skoda-auto.com/en/mini-apps/owners-manuals/pages/superb-3u.aspx?requestOwnersManualOnlineVersion=en/Superb_3U/05-2007/Manual/Superb/online&requestOwnersManualLanguage=en&requestOwnersManualEditionDate=05-2007&requestOwnersManualPage=1&printPage=1&pageId=00197

 

If you don't see AUTO or ECON displayed, then the AirCon should be active.

 

[petrolbloke]

There's no frost icon on mine.

 

I would take it back to the garage that re-gassed it and see if they can tell how much refrigerant is left in the system now. I thought garages were supposed to test for leaks before re-gassing though...

[KenONeill]

No frost icon on mine either. The "demand temperature" value (lower RHS) reads "Lo", 18..28 step 1 C or "High".

[phazed]

Will do a little more investigating and pop back to local garage for a debrief!

[SurreyJohn]

Sounds like the system is leaking.  

 

Another possibility is a stuck flap,  possibly hot air is being input into vent ducting

there are manual controls (where a cable physically connects the temperature selector to the hot/cold input flap) and climatronic which uses servos.   These servos can fail and hot air flap may be stuck open.

 

 

[Guest]

The only frost icon you get on the Mk1 is when the outside ambient temperature drops below 4.5deg C. With the aircon they have an Achilles heal of failing shafts on the air con pump the pulley may turn but it won’t turn the pump itself. There also can be issues with the pressure switches failing. To find out the fault for that you’ll need someone with vcds diagnostic equipment. 

[phazed]

 I will ask the garage that regassed the system to check the pressure again.

 

From memory , They removed about 500 and put back about 850 gas,(I don't know what the measurement is though).

 

If it is a stuck flap, how can I check? I bet you are going to tell me you have to take the heater box out! 

[petrolbloke]

Try the diagnostic mode on the climatronic unit:

 

[phazed]

20 minutes ago, vrsTom said:

Try the diagnostic mode on the climatronic unit:

 

 

 I ran the diagnostic test as suggested. It came up with 4FA same as the video.

 

When I pressed the button it showed 000. Does that mean it has diagnosed, no faults?

[phazed]

 I also checked with my friendly local garage who we use every week, (my mechanic son has a good relationship with them) and they have said that there is not a leak on the system.

 

My son has also checked the car with his non-VAG diagnostic equipment that is up-to-date. It ran a diagnostic test and moved all the flaps etc in the heater box during its test and did not come up with any faults.

 

 My gut feeling is that the compressor may have died although  I believe there are some senses on the system and I wonder if  possibly one of these maybe faulty?

 

  Does anyone have a spare compressor? 

[phazed]

Can someone tell me the make and code of the compressor?

[phazed]

 As the car has been sitting around for five years a good mechanic friend of mine said it may well be the dryer, (is that the condenser)?).

 

 He said these can become blocked.

 

What do you think?  It is a cheap part to replace. 

[Ttaskmaster]

On 26/07/2018 at 21:57, phazed said:

What do you think?  It is a cheap part to replace. 

Brand new one for an Audi A4 (same platform) from VAG is about £140.

[phazed]

 Where about is it fitted in the engine bay? Probably a silly question as it is probably obvious but can’t say I have seen with the limited cursory glance that I gave it! 

[Ttaskmaster]

https://workshop-manuals.com/skoda/octavia-mk1/drive_unit/1.6_ltr./74_kw_engine_mechanical_components/engine_cooling/removing_and_installing_parts_of_the_cooling_system/removing_and_installing_radiator/

 

[bspman]

@phazed - we have a briskoda parts person that can give you a quote. Best to phone if you've not got a facebook.

 

 

 

[Ttaskmaster]

On 26/07/2018 at 13:04, phazed said:

If it is a stuck flap, how can I check? I bet you are going to tell me you have to take the heater box out! 

 

Nope.

Take out glove box. Lift insulator carpet thing out the way.

Undo the retention plate and drop the blower fan out.

The flaps are directly behind this and you can then run the A/C system while watching to see if they operate. The blower won't be running, so you'll hear if the flap motor is graunching or anything.

Give the ducts, condensor and everything a good air dusting out, while you're there...

 

 

On 26/07/2018 at 08:42, phazed said:

I can rebuild engines but my air-conditioning knowledge is woefully Very thin on the ground!

The air conditioning pump kicks in when the system is switched on and that’s about it.

Any pointers would be appreciated.

 

This is how it works:

 

 

I'm thinking it's either the dryer or the compressor. Mine is doing similar things, but I'm learning.

 

On 26/07/2018 at 15:43, phazed said:

Can someone tell me the make and code of the compressor?

It's an SD7V16 - Audis use the same one

 

On 26/07/2018 at 21:57, phazed said:

 As the car has been sitting around for five years a good mechanic friend of mine said it may well be the dryer, (is that the condenser)?).

 He said these can become blocked.

What do you think?  It is a cheap part to replace. 

 

Sorry, when I said £140, that was for a new compressor. New dryer is about £12.... always replace the cheapest parts first!

No, they don't become 'blocked'. However, they do contain a dessicant and these should be changed every two years anyway... but also every time you open up the regrigerant circuit, exposing it to the air, because the dessicant is then useless.

Same when installing the new one, once you take it out of the packet, get it in quick.

 

I'm about to do my own... Apparently the local KwikFit will take the gas out, let you go fix stuff, and then put the gas back in. They also don't charge you regas fees if the a/c does not work.... apparently. We'll see... 

 

On 30/07/2018 at 13:38, phazed said:

 Where about is it fitted in the engine bay? Probably a silly question as it is probably obvious but can’t say I have seen with the limited cursory glance that I gave it! 

 

Compressor/clutch is part 11&12 and dryer is part 14 here:

https://workshop-manuals.com/skoda/octavia-mk1/heating_air_conditioning/heating_air_conditioning/air_conditioner/summary_of_components_for_air_conditioning_and_heating_engine_compartment_(manual_control)/

 

[phazed]

 Thanks for all of that.  Most useful. 

 

I replaced the dryer after having the gas removed on Saturday morning. It is going in for a re-gas on Thursday so will see if that has done anything. If not, outcomes the glove box! 

[Ttaskmaster]

21 hours ago, phazed said:

 Thanks for all of that.  Most useful. 

 

I replaced the dryer after having the gas removed on Saturday morning. It is going in for a re-gas on Thursday so will see if that has done anything. If not, outcomes the glove box! 

Do it anyway - It only takes 10 minutes if you go slowly and you'll not only check the flaps but get to clean everything out.

Seriously, 20 minutes for the whole exercise, assuming you've never seen this done before.

[phazed]

 Update.

 

Fitted the new dryer and had the system re-gassed, absolutely no cold air.

 

 Remove the glove compartment et cetera and check the operation of the flaps, all working and all clean, not a leaf in sight.

 

So,  switch on the air-conditioning and the pump clutch engages and spins the compressor. All flaps seem to be working in the heater box and the dryer has been renewed, the system is full of gas and the air-conditioning doesn't work.

 

Looks like the compressor is next unless someone  has a better idea. 

[Ttaskmaster]

Nope - I'm about to do my own dryer today, but suspect the exact same issue - new compressor.... well, second hand one off the 'Bay, probably. Can't afford new.

[phazed]

Just be aware. If a secondhand compressor has been sitting around for a while then moisture can get into the moving parts and you may not receive a working compressor. Better to buy a new one if you can source one at a decent cost. They certainly seem to vary in price!

 

As for mine, I luckily found a small independent VAG mechanic in the next village who specialises in diagnoses.  He got my compressor working intermittently but stated that I require a new one. The intermittent working is due to the car having been sat around for five years and probably the air-conditioning system was never used during that period. The intermittent working at the compressor was due to the pistons sticking and this would free up with a light tap on the compressor and work for awhile but then stop.

 

 I am now on the lookout for a compressor. Thank goodness the hot weather has come to an end!