Apologies if this has previously been covered but I'm new and after searching lots of pages I couldn't find an answer.

I have noticed that when the outside temp is very hot (25+) my Mk1 Octavia Tdi Climatronic causes the car to what I can only describe as 'pulse' - it's as though when the compressor kicks in it is putting a 'big' load on the engine and therefore drops the speed by a mph or two. In addition, the aircon can blow icy cold for a while and then blow ambient (this is when it is 25+ outside and I have it set to 18 and in reality with the strong sun it is probably 30+ inside the car so it hasn't got anywhere near cold inside). I have also noticed a groan/judder at about 2500 revs when pulling away in 1st. On a normal day such as today when the outside temp was 22 everything was fine. When I switch to ECON these characteristics go away and the car runs as it should - albeit with a very sweaty driver!

Therefore, I know that the compressor is working and therefore the clutch hasn't disintegrated, but don't know if there may be some other mechanical fault. Perhaps it is just in need of a re-gas - I hope!

Any suggestions from those in the know would be much appreciated.

I'd go with the regas first, and maybe check the nut on the compressor clutch just to make sure its not loose.

If the gas is low the compressor will have to work harder so I reckon thats your problem. How olds your car? If it's over 6 years old it probably needs a regas

I had the pulsing problem on mine, and it turned out to be a faulty V71 flap motor.

£70ish later (and some scratched hands!) and it's all working fine now.

Nice and icy cold and it's never been re-gassed (6 years old).

Could be a combination of issues with yours, maybe the faulty V71 and it may also be running low on gas/oil.

VAGCOM would tell you about the flap motor.

I had the pulsing problem on mine, and it turned out to be a faulty V71 flap motor.

£70ish later (and some scratched hands!) and it's all working fine now.

Nice and icy cold and it's never been re-gassed (6 years old).

Could be a combination of issues with yours, maybe the faulty V71 and it may also be running low on gas/oil.

VAGCOM would tell you about the flap motor.

It is 6 years old but was last re-gassed 3 to 4 years ago when the clutch failed (under warranty thankfully). In addition, there are no fault codes showing on the Climatronic display. Would the faulty flap not show here? Anyway I'm going to book it in for a re-gas next week at the Morecambe dealership - £75.50 which whilst being more expensive than Kwik-fit I would hope they are a little more careful (there are a few threads on here which mention Kwik-fit putting in too much oil).

I'm sure Skoda dealerships were doing a regas offer this summer for £25-30ish. I got a card through the post. Will see if I can find it tonight.

Try £80 inc the service, but I'd get the nut on the compressor clutch checked sharpish and if required replaced with a new clutch. A lot cheaper than a new compressor, which is usually required if it comes off.

Yep looks like it wasn't a regas just a clean of the system with an antibacterial flush according to the card.

My Mk1 does this pulsing.

I had it plugged into a code reader the other day and 2 air-con faults came up.

code: 00792 = Aircon Pressure Switch

code: 01274 = Airflow flap positioning motor (this could be the air into engine saying that?)

I will get mine re-gassed I think

The flap motor is behind the dash and directs the air to the various vents around the dash. It's part of the climatronic system,

The flap motor is behind the dash and directs the air to the various vents around the dash. It's part of the climatronic system,

and its a right barsteward to change!! but fixed my pulsing......

Took the car in to the Main Dealer, David Ian, in Morecambe for a 'Aircon service' last week. I explained the problem which I was having and they said that they would investigate as part of the service/re-gas. When I went to collect I was told that they could not find any faults (neither mechanical nor electrical - no fault codes showing), and the refrigerant level was within tolerance. I can only assume that they had to extract the refrigerant in order to find this out. Anyway, as they couldn't find any problem they said it was free of charge. We haven't had any really hot weather since so I don't know if the intermittent problem is still happening.

So for the grand price of £0.00 I have had them check it all out, possibly re-gas as well, and have peace of mind that there are no significant problems. It still doesn't explain why I did have the problems in the first place but I'm no worse off.

Thank you to David Ian Skoda for restoring my faith in the dealer network. I had previously used Woodheads in Blackpool (now closed down) and had nothing but trouble with them and their customer-unfriendly approach.

Unless you run the car in econ mode, then as long as the temp is over 4c then the aircon is in use so it looks like you may all be sorted.