My Skoda Octavia 1.6 Airconditioning suddenly stopped cooling well. Took it to the local service and was told the gas was low and maybe a leak in the evaporator. The technician never opened the evaporator so I am a bit weary. Any ideas

Yes, first check that the 14mm nut on the compressor clutch is secure. Check that the centre (clutch) of the pully rotates stiffly and rotates the shaft and isn't rattling around or able to spin without rotating the compressor shaft. The splines go and the nut comes undone then the clutch ends up being not connected to the ac pump and no ac.

If all that's okay, go get it gassed up and dye leak checked.

Greg.

Thanks Greg. The Airconditioner actually works but just not as cold as I am used to. I like your advice about getting it gassed up and a dye leak check. One question though - How is the dye leak check performed

Achorex

You can try a re-gas youself, a regas canister is available in halfrauds for around £35 and is easy to use and has dye incorporated to help a garage spot the leak with a ultra violet light if it is leakiing. A top up using the kit from halfrauds work for me.

When the splines are going or clutch issues, it's possible to have the ac turning but not as fast as it should due to slipping.

Also have it scanned for fault codes, something like a flap motor issue could cause it.

They will put dye in the system, if there is a leak you can then find it, It's put in via the service valve along with any needed refrigerant.

Yes, first check that the 14mm nut on the compressor clutch is secure. Check that the centre (clutch) of the pully rotates stiffly and rotates the shaft and isn't rattling around or able to spin without rotating the compressor shaft. The splines go and the nut comes undone then the clutch ends up being not connected to the ac pump and no ac.

If all that's okay, go get it gassed up and dye leak checked.

Greg.

Where is the 14mm nut? Sorry I have no idea where anything to do with air con is on my car!

Item number: 150049030203

£25 if you want to go that route. Not sure without pressure gauge on the can how you can avoid over pressurisation though

AC compressor lower front pulley, single nut in middle.

Where is the 14mm nut? Sorry I have no idea where anything to do with air con is on my car!

"Check that the centre (clutch) of the pully rotates stiffly and rotates the shaft and isn't rattling around or able to spin without rotating the compressor shaft"

I got my dealer to add the clutch back on (found it on the bellypan) but mine is still not cold (makes no difference if "ECON" mode on or off. How do we actually check whether the compressor shaft is turning? I don't want to waste any more cash re-gassing if the compressor/clutch is buggered. Have already spent loads on turbo vacuum testing and an N75 valve, which haven't sorted out the turbo after all...

If it's on the bellypan 99% chance that the splines are stripped. So he may have put it on and done the nut up, but it will spin on the shaft.

You need it on auto, down to the min 'cold' temp setting, with fans on. Then go and physically look at the bottom front pulley, the nut in the centre should be spinning with the rest of the pulley. Now turn the a/c off. Look again, nut should be stationary and the centre piece (clutch) of the pully should be stationary, but the outside rim turning with the belt.

If you find the rim and the centre clutch piece turning when the ac is on but the nut (shaft) isn't, or is turning slower, it's the splines on teh shaft gone = new ac pump (about £60 second hand).

If when you put ac on the clutch isn't turning and centre shaft is still, eg no difference to ac off, then it's likely the system needs re-gassing or has a another fault.

Any decent mechanic should be able to diagnose this for you in 30 mins!

Greg.

PS - it shouldn't have cost you anything to test vacuum and n75, you can simply observe it's operation when you start the car to see if the vanes are moving as they should - 99% chance they are not. If they don't move properly it's easy to bridge the vacuum lines on the n75 and see if it's faulty.

"Check that the centre (clutch) of the pully rotates stiffly and rotates the shaft and isn't rattling around or able to spin without rotating the compressor shaft"

I got my dealer to add the clutch back on (found it on the bellypan) but mine is still not cold (makes no difference if "ECON" mode on or off. How do we actually check whether the compressor shaft is turning? I don't want to waste any more cash re-gassing if the compressor/clutch is buggered. Have already spent loads on turbo vacuum testing and an N75 valve, which haven't sorted out the turbo after all...

Thanks Greg. I'll have a look, but am assuming I'll need to remove belly pan and side cover in wheel arch to be able to see the end of the pump properly.

As the car has a limited warranty (guy I bought it off says he will help towards the cost) I'm gonna get a recon turbo put on, I simply haven't got the time or inclination to remove and strip down the turbo.

Hello Greg, I hope you are still there. I checked and the rim, centre clutch and shaft are all turning. I had noticed a little whistling sound which my technician said was coming from the expansion valave but didn't seem to think anything was wrong with that. I decided to add some gas and at first it cooled better but then it seems to have gone back to usual and now the whistling noise is louder and I seem to think it has too much gas. I want to take it to a technician but need to know what could be wrong first

Hi, my aircon isn't working (octavia scout), KwikFit tried a regas but still nothing, they said it was empty, their leak test was ok, but no cooling after the regas.

I visually checked the compressor clutch and both it and the nut/shaft spins with the pulley all the time no matter what combination of Auto/Econ I try, the pulley and the clutch seem locked together, even with the engine off it is impossible to turn the clutch even a little bit.

My understanding was that in Econ mode, the clutch would not engage and remain stationary whilst the outer pulley would continue to spin being driven by the belt. Is this right or is what I am observing correct?

Thanks,

Stu

Edited 1 July, 201016 yr by spayton

Hi, my aircon isn't working (octavia scout), KwikFit tried a regas but still nothing, they said it was empty, their leak test was ok, but no cooling after the regas.

I visually checked the compressor clutch and both it and the nut/shaft spins with the pulley all the time no matter what combination of Auto/Econ I try, the pulley and the clutch seem locked together, even with the engine off it is impossible to turn the clutch even a little bit.

My understanding was that in Econ mode, the clutch would not engage and remain stationary whilst the outer pulley would continue to spin being driven by the belt. Is this right or is what I am observing correct?

Thanks,

Stu

no you have a different tyoe of air con compressor. the later ones do not have a magnetic clutch as they run permanently and the compressor regulates the pressure and flow on demand..

the newer units are prone to failure tho

thanks - that answers my question then.

but I'm still intrigued as to what the thing that looks like a clutch is for, it must have some function otherwise just a usual pulley+shaft+nut would have done the job of driving the compressor.

I'm not sure, but it may be a sprague clutch (one-way drive)?

I think it is a big vibration damper built into the pully.

My aircon wont cool properly either, despite using DIY can so thinking there is more wrong with it, also I'm unable to get the temp display to go below 19 deg with Auto switched on, it will go to Lo when Econ selected but either way its not cold. Should the Auto setting go to Lo?

Also when I start the car, with the cooling switched off everything is silent but start it with cooling on and there is a screech like the noise you used to get with fan belt slipping and listening near the aircon compressor it sounds like a rumbling noise after the screech has stopped. Any thoughts on this?

I can select "lo" (and "hi") with the Climatronic in Auto mode.

The screech sounds like either the belt slipping when the extra load from the a/c compressor hits it, or the clutch (if applicable).

can you get some one to watch the ac clutch while its switched on and off, it may be the compressor seized or something.

also i have just fixed a few octavias that didn't have cold ac by replacing the receiver dryer unit.

http://www.eurocarparts.com/ecp/c/Skoda_Octavia_1.8_2002/p/Car-Parts/Cooling-and-Heating/Air-Conditioning/Accumulators-and-Receiver-Driers

£90 from TPS or £16 from euro car parts. easy to fit too and changing some has saved the compressor from being changed instead (very similar symptoms to a broken compressor, no high pressure or suction)

pretty simple job to fit too

I can select "lo" (and "hi") with the Climatronic in Auto mode.

The screech sounds like either the belt slipping when the extra load from the a/c compressor hits it, or the clutch (if applicable).

Thanks Ken ,

further attampts to isolate the sound have led me to believe its related to whether the compressor is activated or not, start the car with Econ or Auto selected and there is no screech, start without on normal cooling and it screeches, also when you deselect Auto or Econ it screeches briefly, would this relate to the " clutch" on it?

So if I cant select Auto below 19 degrees is that a problem with the climatronic control unit itself?

Any help appreciated

It sounds like I may be correct in thinking the screech is from the shock load of the compressor starting up once the engine's running. It's probably going to be worth checking that the aux drivebelt tension is correct before suspecting a fault with the compressor (or drive) itself.

It also sounds like you've an unrelated fault with the control unit, but as long as you can select 18 or 19 deg cabin temp, why worry? The only reason I can see for using "lo" is if you have a young lady with a tight and thin top on board!

It sounds like I may be correct in thinking the screech is from the shock load of the compressor starting up once the engine's running. It's probably going to be worth checking that the aux drivebelt tension is correct before suspecting a fault with the compressor (or drive) itself.

It also sounds like you've an unrelated fault with the control unit, but as long as you can select 18 or 19 deg cabin temp, why worry? The only reason I can see for using "lo" is if you have a young lady with a tight and thin top on board!

Lol! Ken how did you know? I have a young Norwegian lady who loves the cold! Heh heh! At 18 degrees selected its still not cold enough for me or her!

Just so I know, when you select Lo in Auto mode does the word Auto stay displayed? It disappears on mine and doesnt seem to change how cold it gets.

I think it is a big vibration damper built into the pully.

It does look like what you described, there are 3 springlike things on it - for everyone's benefit here's a couple of snaps.

From the top:

From the side: