Air con gas lifespan...

Folks, Anyone got any experience with the lifespan of 996 Air Con gas? Previous cars I've owned have still been going at 6-8 years old, with no re-gas. My 996 had leaking radiators replaced under warranty, and the coolant leak had also corroded the Air-Con radiator (or condensor?). Anyway...18 months ago the system was drained, the part replaced and it re-filled whilst the radiators were also changed. Now, I find the Air-Con doesn't work...the clutch is not engaging...presumably as a result of the low pressure switch shutting the system down as it's empty. The OPC were supposed to have ensured the system is leak-proof...but is seems perhaps not. Is it acceptable for the refrigerant to have dissapeared in 18 months? I would suggest not. I'm just looking for a bit of advice before I go back to my OPC and wave my Extended Warranty at them. looking for a repair! Any thoughts? Thanks in advance. Glen.

should last longer than 18 month as you well know, wonder if they have nicked a seal when refitting the condensors or maybe another leak has occured...get em to check it if still covered

The manufacturers of air conditioning compressors, condensors, receiver driers etc all recommend that all air con systems are serviced, including vacuum testing, oil renewal and regassing every 24 months. I know when I have had this done to my Boxster I had 400 grams of gas taken out of the system and 900 grams (off the top of my head) were put in.. the 400 to 500 grams lost was according to Porsche reasonably normal due to R134a being a very fine gas (molecule wise) and as the pressure goes down as the gas is lost over months, so does the rate of loss. So you might even go 5 years without needing a regas, even though after 2 years you had lost 50% of it. It being empty after 18 months would point to a problem though, but a problem that may be hard to find if it takes another 18 months for the gas to go walkabout. I do know when my local independent regasses a system he always puts a die in the gas to if it leaks out he can use a UV lamp to look for where its leaked from, as well as some expensive looking sniffer system. Could it be a blown fuse?

Could be a fuse, I suppose. A friend with a 993 is continually chasing leaks with his...and always behaves like this; clutch doesn't engage when the gas pressure goes, hence we suspect the same. I think i'll take it back to the OPC...I've emailed them to seek clarity of whether it's covered by the Warranty, but after having work done only 18 months ago, I'm not impressed if being empty is acceptable to Porsche. My 12 year old Golf GTI has been re-gassed once in that time - and only after an Air Con system clean and de-oderise as it was getting a tad smally. What is it with 996s and their inability to hold onto their fluids...if it's not oil it's loosing, it's coolant or refrigerant.

This is something of a sales ploy and means of extracting money from the unwary. How many times have you had the refrigeration system on your fridge or freezer serviced ? The actual refrigeration part of an air conditioning system, be it a domestic, commercial or car does not need servicing as such. The air filters need cleaning or replacing, the evaporator and condenser coils can require cleaning and the condensate drain should be checked. The refrigeration gas pressure may be checked to verify if it is within limits. If the pressure is low the system has a leak. It is a simple as that. The gas itself does not deteriorate and neither does the oil. If you have a leak it is imperative to find it before adding gas. leak testing with dye is ok but a bit corny. The best way to leak test is with an electronic detector but the most simple way is to inspect the pipe unions. If you are loosing refrigerant gas then you are loosing oil as well and you will find an oil film/mist around the leaking union. On a car system the refrigeration system is not fully hermetic ( sealed) as the compressor is mechanically driven via the fan belt, so other than unions the only place that leakage may occur is around the compressor pulley shaft. Corrosion of the condenser or evaporator can occur and cause leaks but actual leakage from the coil itself is rare unless caused by mechanical failure due to excessive vibration. Many dealers and Air conditioning specialists will claim that the Refrigeration system needs servicing. What they do not say is that you have a leak,they can't find it and it is so much easier to reclaim the remaining gas and refill the system knowing that you will return for the same job in the future! If you want a system regassed,get whoever does it to first find the leak then give you a 12 month warrany on the repairs.

All I can tell you is I have a 1997 Boxster made in January 1997. No parts of the a/c system have been replaced or filled up or recharged. It still works 11 plus years later. There is a part under the dash that can leak. I forget what it is called.

Are you seriously comparing a Porsche air conditioning system which if looked after will last 30 years, to a fridge or freezer which will pack up about one month after the manufacturers warranty expires? A fridge or freezer has an electrically driven diaphram compressor, as many moving parts as the average wallet and designed to work in a stationary ambient environment and has no pag oil. A car air conditioning system is mechanically driven, has a compressor which will see serious extremes of temperature, has to avoid cavitation and has oil, much like engine oil, which picks up contamination as parts in the compressor wear, is hygroscopic so picks up corrosive humidity every time the system goes atmospheric (such as a compressor failure) and I think most importantly, costs a hell of a lot more than a couple of 50's on a counter at Dixons to replace as with the fridge freezer comparison. I dont like mentioning this on car forums, because I would end up getting asked air con questions all the time, but I used to work for Valeo designing air conditioning components.. My advice is get your air conditioning serviced on your Porsche every couple of years, it will cost peanuts and will ensure it continues to give good service without suddenly costing a fortune (could also avoid having to have it completely re-gassed on a regular basis). The other problem is with germs and bacteria which breed on the surface of the evaporator in the dash and have all kinds of health risks, let alone can make your car smell like a gym sock locker. A proper air con service will decontaminate this part of the system also. Tony_M recommends never get it serviced and treat it like a fridge or freezer. Your choice

I think you must be the exception rather than the rule. Part of the problem is what happens when the air con system becomes atmospheric due to a degraded condenser. Maybe condensers in Europe fail more often due to damp winters, salt on the roads and accumulating wet leaves against the condensers. Following a condenser failure, the normal atmospheric air that our lungs love so much cause the PAG oil in the air con system to be contaminated.. Usual main dealer or independent specialists will repair by replacing the condenser and re gassing. Unfortunately this will leave most of the contaminated PAG oil in the system to corrode the new condensers from the inside out, as well as damaging the compressor and the seals. An air con service will see the pag oil drained and replaced on a regular basis (every 24 months) but may also spot a condensor failing sooner, or catch a system low on gas sooner, therefore avoiding the system ever getting to a point of needing a condenser in the first place. Another thing that never gets done, is coating the condenser.. not painting it or anything like that, but spraying it with a protective product such as corrosion-X which is like an oil which protects aluminum from corroding... I think if people were to clean their condensers once or twice a year, protect them with corrosion-x and have a 24monthly air con service, they would save money in the long term, even taking into account the cost of the air con service.

100% Correct. If it a'int broke don't fix it ! A sealed system be it in a car, fridge, freezer, industrial, commercial, or domestic system does not need the Refrigeration system 'Serviced' because it is sealed. If it leaks gas you have a problem and the leak must be rectified before regassing. The remainder of the components require external cleaning and as I said before the filters require cleaning or replacement, but as far as the actual refrigeration system is concerned there is no logical reason to reclaim the gas and refill it with the same quantity of gas if it hasn't leaked any gas at all. The same goes for the oil in the system. Your choice !

Well, it's booked into Aberdeen OPC on the 15th to have the problem looked into. They will have the car two days (lending me a Chelsea Tractor to get about in...heaven knows how I'll find the money to keep that damn thing in fuel!) and hopefully will find the leak, repair and re-gas the system. I'd like to think that the warranty on the last work that required the system to be split and re-gassed, or the extended Porsche Warranty, would pick up the costs...but I'm not confident. Watch this space...

Problem traced to a holed drivers side condensor...not sure if it was corrosion or impact damage, but Aberdeen OPC kindly replaced and re-gassed it with my extended warranty picking up the bill, so I can only conclude it was a corrosion issue. Superb service from Aberdeen OPC as usual...and they even let me borrow a Cayman S for 2 days whilst mine was in - and I'm deeply impressed with the Cayman!

A fridge freezer has about as much in common with a car air conditioning system as a nuclear warhead has to do with a nuclear power station. A fridge freezer compressor is a simple device working much in the same was as a audio speaker works. A automotive air conditioning compressor is a rotary device with mechanical wearing components lubricated with PAG oil. The PAG oil is there not only to lubricate the compressor, but also to keep debris from wear etc in suspension within the oil, while also cleaning this debris from the compressor. If you do not change the PAG oil, the contamination of the oil just increases, which increases the rate of wear within the compressor. Thereofre, an air conditioning service is there to replace this oil and get the contamination out of the system. Likewise, as the quantity of gas within the system drops, the compressor has to work harder to build up pressure to the point where the gas will change state between liquids to gas and cause the cooling effect. Which again causes wear and increased fuel consumption. Unfortunately the 996 has no air conditioning pressure display to warn the driver of this, therefore a service of the air conditioning is to keep the gas level at the correct level and therefore reduce the stress on the compressor and engine driving it. Seeing as you like to make comparisons to domestic situations. Think of a light bulb for a moment, we change light bulbs once they blow, we do this because they cost a couple of pounds and cause no damage when they eventually fail. Now imagine that light bulbs had been found to typically blow at some point after two years, and yet imagine they still only cost a couple of pounds, but can cause a thousand pounds worth of damage if they failed.. I bet if this was the situation you would change your light bulbs every couple of years as a precaution. In this example the cheap light bulbs are like the relatively cheap gas and PAG oil and the thousand pounds worth of damage is like the costs of a failed compressor. If you buy a new 996/997 couple of years, maybe every four years, you will probably never have your air conditioning serviced because you do not think its needed, and you may not ever suffer a serious failure. But I bet later owners of the cars you leave behind you will not thank you for not having the air conditioning serviced when their compressor fails. On the other hand, there is also another factor with air conditioning servicing. If you sell your car and in the history it shows that you have invested every couple of years having your air conditioning serviced, do you not think that sends a strong positive message to that future owner that you have been a careful owner who has pampered the car. I think it does. Everyone has a right to an opinion, but the dangerous thing with the internet is that readers may take it as gospel. You think I and the company I used to work for (europes largest air conditioning manufacturer) are wrong regarding servicing. The thing is, my advice will certainly not cause any damage (in my opinion it will prevent it) your advice on the other hand could cause damage and certainly can not benefit as it advises no preventative action. There are probably people out there on the internet who once had a old ford cortina for a few years and never changed its oil, they probably tell people about it and say it never missed a beat and went on until they sold it. Does their experiences constitute good advice? Would you advise someone does not change their brake fluid, engine oil, transmission oil, coolant, power steering fluid? Surely whenever you have had any of these changed the oil fluid was still servicable? would the engine have certainly blown up if you had not changed the oil?