air conditioning failure

[claudiu]

Hi Porsche lovers!

Got into my lovely 2000 Carrera 4 today and noticed that the air conditioning system simply did not cool down the interior anymore, although the fan was at the max as if trying to bring the temperature down to 22 degrees. I've tried with lower temperatures as well. I've checked all the 4 fuses and, sadly, they are ok...

What do you think is wrong, please?

[1999Porsche911]

Check to see if the compressor clicks on when the air is turned on. Have someone push the A/C button while you watch the compressor on the engine.

[Paul Fraser]

As you live in sunny Britain (sound of rain p*ssing down in background) it is going to be one of two things I'll wager:

1. either the condensers at the front of the car have corroded (shine a light through the bumper vents into the corners and see if you can spot the tell-tale dark stain at the corner of the aircon condenser/radiator.

2. the pipes on the right hand underside of the car have corroded. See if you can see any fluid/staining on the pipes, usually at the plastic supports.

Had both these problems on my 97 Boxster and 97 996, repaired both two months ago. (Background sound of till opening, emptying and closing.)

[claudiu]

Check to see if the compressor clicks on when the air is turned on. Have someone push the A/C button while you watch the compressor on the engine.

Thanks for this. I do not seem to hear any click, and unfortunately I do not know exactly where to ask my son to look for the compressor... I'll have to take her to a specialist...

As you live in sunny Britain (sound of rain p*ssing down in background) it is going to be one of two things I'll wager:

1. either the condensers at the front of the car have corroded (shine a light through the bumper vents into the corners and see if you can spot the tell-tale dark stain at the corner of the aircon condenser/radiator.

2. the pipes on the right hand underside of the car have corroded. See if you can see any fluid/staining on the pipes, usually at the plastic supports.

Had both these problems on my 97 Boxster and 97 996, repaired both two months ago. (Background sound of till opening, emptying and closing.)

Thanks, and how much did it cost to fix this?

[Loren]

Before you do that you might check the fuse E7.

That would be the 5th row down from the top and 7th fuse from the left.

It should be 7.5A.

[claudiu]

Before you do that you might check the fuse E7.

That would be the 5th row down from the top and 7th fuse from the left.

It should be 7.5A.

I've already checked all the relevant fuses, or at least I think I did, but I'll have another look. Thanks dear Loren.

[1999Porsche911]

Looking at the engine from the rear, the compressor is the top, right pulley that the serpentine belt goes around. When the A/C is off, the center of the pulley should not be turning. When it is on, the center should be spinning. You can also check from inside the car by turning off and on the A/C. You should notice a change in idle between ON/OFF.

[Paul Fraser]

The pipes underneath the car cost about £100-110 and would probably take 2-3 hours labour. A condenser can be got for £110 each if you use Eurocarparts Leeds (they do a Porsche Club Forum discount, just ask), although you'll probably need a new receiver dryer as well, £45, and o-rings, £10. A garage/OPC will quote £150-200 for a condenser and probably another 2-3 hours labour for that -- same length of time to do both, or not more than 15 minutes more. Regas another £50-100.

But you need to find out what it is first: might be worth taking it in for a high pressure nitrogen test if the fuses/compressor check out. On both of mine I could hear the gas hissing out. Better, get them to put some dye in the system and this will show leaks under black light.

PS I believe the idle speed can change even if the compressor is not working. My aircon guy told me that the aircon switch sends a signal to the DME which increases the revs; this is independent of whether the compressor is actually working...

Edited August 15, 2006 by Paul Fraser

[claudiu]

Looking at the engine from the rear, the compressor is the top, right pulley that the serpentine belt goes around. When the A/C is off, the center of the pulley should not be turning. When it is on, the center should be spinning. You can also check from inside the car by turning off and on the A/C. You should notice a change in idle between ON/OFF.

Thanks a lot, the feedback to follow as soon as I sort it out...

The pipes underneath the car cost about £100-110 and would probably take 2-3 hours labour. A condenser can be got for £110 each if you use Eurocarparts Leeds (they do a Porsche Club Forum discount, just ask), although you'll probably need a new receiver dryer as well, £45, and o-rings, £10. A garage/OPC will quote £150-200 for a condenser and probably another 2-3 hours labour for that -- same length of time to do both, or not more than 15 minutes more. Regas another £50-100.

But you need to find out what it is first: might be worth taking it in for a high pressure nitrogen test if the fuses/compressor check out. On both of mine I could hear the gas hissing out. Better, get them to put some dye in the system and this will show leaks under black light.

PS I believe the idle speed can change even if the compressor is not working. My aircon guy told me that the aircon switch sends a signal to the DME which increases the revs; this is independent of whether the compressor is actually working...

Thanks a lot. I'll make sure I feed back to all of you nice people once I get it fixed...have to rush to work now...at least it's not a hot day today in Chelmsford, Essex...

[Sly74]

Hi There

I have been reading through the current postings re: Air conditioning on the Carrera 4, I have the same

problem on my 1998 996 Carrera Tiptronic S, forgive me as I am very new to Porsche's, would all of

the suggestions given to fix the a/c for the C4 apply to my 1998 996?

Thanks

[Loren]

Hi There

I have been reading through the current postings re: Air conditioning on the Carrera 4, I have the same

problem on my 1998 996 Carrera Tiptronic S, forgive me as I am very new to Porsche's, would all of

the suggestions given to fix the a/c for the C4 apply to my 1998 996?

Thanks

Yes. All of the AC is the same.

[Sly74]

Hi There

I have been reading through the current postings re: Air conditioning on the Carrera 4, I have the same

problem on my 1998 996 Carrera Tiptronic S, forgive me as I am very new to Porsche's, would all of

the suggestions given to fix the a/c for the C4 apply to my 1998 996?

Thanks

Yes. All of the AC is the same.

Thanks for the info, do you know if the control unit in the dashboard is prone to breaking?

Thanks again

[Loren]

Find a shop with a Porsche PST2 or PIWIS tester and they can diagnose the cause of your problem in few maninutes with just a few tests.

[Paul Fraser]

Loren, what info does this give them? Does it indentify a leak, compressor problem, control problem, etc.?

[Sly74]

Find a shop with a Porsche PST2 or PIWIS tester and they can diagnose the cause of your problem in few maninutes with just a few tests.

Loren, how much does that cost where you are? just want to get an idea before I call a local

garage.

Thanks

[Loren]

You can read a number of actual values.

You can look at input signals.

You can manually perform action with the drive links.

You can verify/change coding of the AC system.

And, there is a System Test that you can run (although I have never used it).

[claudiu]

Checked fuses again this morning (including E7), all ok, also the compressor, that clicks into spinning as it should. A week on Thursday an air conditioning specialist will have a look at the system and hopefully fix it, most likely by filling it up with gas. Weird however that the gas could have disappeared within 8 hours, so maybe it's not that...I promise I will feed back anyway...

[Paul Fraser]

Good luck but I suspect he'll either stop after the pressure test (because the system deosn't hold pressure) or fill it and it will be empty again in fairly short order... If he adds dye this won't be a complete loss.

Did you do a visual inspection of the condensers at the front of the car and the pipes under the rhs?

PS Thanks Loren for the screenshots, very informative.

[claudiu]

Good luck but I suspect he'll either stop after the pressure test (because the system deosn't hold pressure) or fill it and it will be empty again in fairly short order... If he adds dye this won't be a complete loss.

Did you do a visual inspection of the condensers at the front of the car and the pipes under the rhs?

PS Thanks Loren for the screenshots, very informative.

Thanks again. The condensers and the pipes looked ok to me (hopeless DIY mechanic, me) but a non-Porsche mechanic also could not spot a leak. I am pretty sure that the air con guy from "Bonair" will use a dye and, once identifying the area of the leak will try to solder it somehow before recharging the gas...that would cost me in the region of £100, but you might well be right and I will end up eventually spending a few hundred quid in a Porsche garage...I'll feed back after next Thursday...promise!

[cannonball]

I have a 99 C2.

Mine did the same thing last summer, turn on the A/C no cool air.

I bought a $24 AC Oil/Coolant kit and it showed my coolant being low.

I added more coolant to the correct level and it has been cold ever since.

Just something to check before you spend all that money.

Brian

Edited August 19, 2006 by cannonball

[Paul Fraser]

Some of those kits have sealant in them so you need to take care. When the sealant hits moisture it forms a solid. This can seal your leak, but can also wreck your expansion valve or compressor. Systems that have been open to atmosphere have a risk of this, as compared to those that are still holding some pressure.

[claudiu]

Some of those kits have sealant in them so you need to take care. When the sealant hits moisture it forms a solid. This can seal your leak, but can also wreck your expansion valve or compressor. Systems that have been open to atmosphere have a risk of this, as compared to those that are still holding some pressure.

Thanks Paul, and also thanks to Cannonball, for the latest pieces of advice. As I am lacking the DIY skills many of the colleagues in the Forum seem to possess, I will see on Thursday what the specialist in air conditioning will have to say and...watch this space!

[claudiu]

As promised, I am feeding back to you all what happened today when the Airconditioning Specialist from Bonair arrived to fix my air con system.

He has been in business since 1986 and he told me that it could well be that my 2000 Carrera 4 has been slowly losing the gas over the years, as all cars with air con do. He measured the pressure first and told me that I have about 10-15% of gas left in the system, then he created a vacuum for about 20 minutes and subsequently refilled the system. He added a green dye so that in case the system flops again, then we would at least know which parts are cracked and replace them. Today it all cost me only £70, and I am glad that I did not go to the Porsche garage for it, but if there is a crack in the pipes or radiators at the front, then it will cost hundreds of pounds sterling to repair...

Thanks again to all of you who've helped me with advice. :thumbup:

[Sly74]

As promised, I am feeding back to you all what happened today when the Airconditioning Specialist from Bonair arrived to fix my air con system.

He has been in business since 1986 and he told me that it could well be that my 2000 Carrera 4 has been slowly losing the gas over the years, as all cars with air con do. He measured the pressure first and told me that I have about 10-15% of gas left in the system, then he created a vacuum for about 20 minutes and subsequently refilled the system. He added a green dye so that in case the system flops again, then we would at least know which parts are cracked and replace them. Today it all cost me only £70, and I am glad that I did not go to the Porsche garage for it, but if there is a crack in the pipes or radiators at the front, then it will cost hundreds of pounds sterling to repair...

Thanks again to all of you who've helped me with advice. :thumbup:

Claudiu

My car is booked in with a local garage to check over my A/C system, have read most of your details about

your A/C and what you have tried etc, can you let me know did it just stop working one day? also now that the system has be re-gassed, is the aircon really cold?

Phil

[claudiu]

Claudiu

My car is booked in with a local garage to check over my A/C system, have read most of your details about

your A/C and what you have tried etc, can you let me know did it just stop working one day? also now that the system has be re-gassed, is the aircon really cold?

Phil

Dear Phil,

The aircon works as new again since yesterday afternoon but if it fails again before the expected 5 or 6 years, then it means that a more serious leak exists which needs fixing. As regards the other question, yes, I went from having to not having an efficient air con system within a day and the specialist said this can happen when the amount of gas drops below a minimal level...Good luck!