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-   -   A/C Died (http://986forum.com/forums/boxster-general-discussions/29238-c-died.html)

Viper5 06-10-2011 08:34 AM

A/C Died
Lately my 2000 S is not blowing cold air. It is just ambient temperature. I've never dealt with this system before and would like to know probable causes from most likely to least likely if possible. I'm guessing I may need more freon but thats just speculation. Any help would be appreciated. Thanks.

jhandy 06-10-2011 09:17 AM

first check all fuses.
Is the snow flake on the display?
change the temp control, does it get hot? then a little cool?
if they are fine, then maybe a leak in the system. Listen for the AC clutch to engage and disengage. You can attach a pressure tester device, dont know if you would put it on the high or low side. Check on that...

If no leak, then the Ac compressor died.

There is also something else that controls the AC compressor. I know this because if you have the AC on, and then accelerate strongly, the AC compressor turns off to save it for HP.
Whatever does this, may be stuck in the "AC off" mode.
Someone else who knows more about that please speak up....

It may be the DME that does this.....if so, maybe unplug the battery and let it reset????

Viper5 06-10-2011 09:26 AM

All I can tell so far is that when I turn the a/c on, I can hear the engine area change sound like it is adjusting. Not sure how useful that is. Also, I have the service manual and it says it could be 3 different things, one of which is the amount of refrigerant too low or high.

The snow flake is on the display. If I'm not mistaken that is the compressor symbol right? I thought that was just a software thing and not related to whether the compressor was working or not.

I am actually trying to work on a CEL (not related to a/c) so I did disconnect the battery. I'm about to go out for a drive to test some things so will report back on the a/c issue.

Viper5 06-10-2011 01:13 PM

After asking around it seems that I am low on refrigerant. There appear to be two different places to insert the can. One is low and one is high I think. Which one is which?

Jake D 06-10-2011 03:24 PM

I forget which one is which. They are up by the battery. My car had the same issue last year. Just needed a little boost in freon and it was good to go. Out of curiosity more than anything, I took off the access panel in the cabin and actually watched the clutch kick on and off on the compressor. I mainly just wanted to see the engine for the first time.

san rensho 06-10-2011 05:26 PM


Originally Posted by Viper5
After asking around it seems that I am low on refrigerant. There appear to be two different places to insert the can. One is low and one is high I think. Which one is which?

The hose will only fit on one, the high side and low side have different size connectors so you can't make a mistake. Depending on how much you have to put in, you might want to get one can of refrigerant with oil.

The $25 starter kit with a reusable hose with a guage is one of the best investments I've mad.

Cloudsurfer 06-10-2011 06:12 PM

Really? Just take it to an A/C shop and have it done right. First off, if the system is lacking refrigerant, it went somewhere, so first you need to find the source of the leak. Then, you need to pull a good vacuum down on the system. Then, you must charge it with the correct amount of refrigerant, with the appropriate percentage of oil to properly lubricant the compressor.

Viper5 06-10-2011 06:39 PM

I was able to measure it today and determined that it is has an excessive psi. What could this mean?

Jake D 06-11-2011 03:39 AM

Mine read higher than normal last year too. I still put some in and that fixed it. What kind of numbers are you talking?

The only other thing I can recall with doing A/C work and having excessive pressure is that you could have a blockage somewhere causing more pressure. But I think if that's the case then the other line should read low. I wasn't certified to mess with A/C stuff so most of the time when it came to the freon end of the job, my boss would jump in and finish it up.

Viper5 06-11-2011 09:34 AM

I should have been more specific. I am talking around 120 psi. It is in the red on my guage. I was speaking with somebody else at autozone and he too thought it was blockage. How can I resolve this?

Cloudsurfer 06-11-2011 10:42 AM

Just take it to a PROFESSIONAL who knows how to work on A/C rather than guessing at what the problem actually is.

JFP in PA 06-11-2011 10:53 AM


Originally Posted by Cloudsurfer
Just take it to a PROFESSIONAL who knows how to work on A/C rather than guessing at what the problem actually is.

+1. Basic rule of thumb #1: If you don't understand the technology; and/or do not have the correct equipment to deal with it, take it to a pro before you make it both worse and more expensive to fix..............

Viper5 06-11-2011 11:37 AM


Originally Posted by JFP in PA
+1. Basic rule of thumb #1: If you don't understand the technology; and/or do not have the correct equipment to deal with it, take it to a pro before you make it both worse and more expensive to fix..............

How can one be expected to learn with this demeanor? I am not about to start turning knobs of which I have no idea what they are for. I have a more accurate reading from the guages.

My high is 148 and low is 150 so they are about equal.

JFP in PA 06-11-2011 12:35 PM

Let me guess: The car (or at least the compressor) was not running at the time? If that was the case, the numbers you posted are not anything meaningful.

With the compressor running at 20C (68F) you should be at around 12.5 Bar (181 PSIG) on the high side, and around 1.55 Bar (22.5 PSIG) on the low. Both low and high side values will vary with ambient temps.

You are also aware that a PSTII/PIWIS can read A/C system condition and faults, even from memory, as well? Usually cuts diagnostics time way down.

It ain’t always as simple as it looks………….

And just a by-the-by, there was no untoward “demeanor” implied or intended in that response, it was totally factual. We see more A/C systems damaged by badly executed repair attempts than you might imagine. One of the most common: Over filling the system because it isn’t blowing cold enough, resulting in a $1500 to $2000 repair when the original problem could have been fixed for less than $100-200…….

Topless 06-11-2011 01:21 PM

Another reason for the A/C to not blow cold is a stuck or failing mix flap. Sometimes the foam deteriorates and the flap fails so heat constantly mixes with cool. Not a refrigerant issue at all.

Diagnose carefully first, fix the real problem second. :)

Viper5 06-13-2011 11:26 AM

I am in no rush to fix this problem. That is to say I will attempt so cautiously.

The car was running at the time the measurements were taken. The low side was measured at 148 psi. The high side at 150 psi. This was while the a/c was full blast and at the lowest temp. Again, I can hear the compressor engaging as well as detect a change in rpm on the guage.

In regards to the foam, there has been an ongoing issue since I purchased the car used a couple years ago. There is constant foam blowing through the air vents into the interior of the car. Even now I can see some behind the vents. This could very well be what is causing my issue, however I am not sure how.

Since it has always been like this, I never thought it would cause any problems, but now that I am experiencing some, perhaps this could have just been compounding. Maybe overtime the foam has blocked something in the system also causing a higher than normal reading for low side?

I do want to thank you all for trying to help me with my issue as well as advising me to be cautious. I don't feel defeated just yet so I would like to still attempt to fix this without the excessive costs of a professional.

Given my foam issue, is this something that is very likely to be causing a problem? I know it may seem silly to ask since I am having a/c problems but again the foam has always been loose and blowing in and never affected a/c prior (at least not detectable to me). I'm gonna hook up durametric and see if it can reveal something.

JFP in PA 06-13-2011 01:28 PM

The pressure near equalization when running says that it most likely is more deeply rooted than a foam blockage in the ventilation system. The compressor section is not compressing the Freon and then allowing to expand in the cooling section (the pressure differential between the high and low side). You’re A/C loop has over and under pressure sensors, as well as over temperature sensors; any one of these can stop the system from functioning. You could also have a bad compressor section seal, or a blown expansion valve assembly; either of which would also create this condition.. A malfunctioning dash control unit is also a possible suspect.

Topless 06-13-2011 02:58 PM

This might be useful:

If you have foam coming out the vents your mix flap is toast. Even if you get the refrigeration working properly it will not give you proper A/C due to the failed flap. A DIY was posted awhile ago but I could not find it.

JFP in PA 06-13-2011 03:07 PM

The mixing flap can cause the car to blow warm while the A/C seems to be functioning normally, the flap being disabled will allow heated air to mix with the cooled air, so the output seems warm; but it does not disable the compressor from reaching normal operating pressure differentials, which is what he is seeing. I think his issue lies elsewhere………..

If you want to look at checking out the flap, RennTech has a method in their DIY section I believe.

Viper5 06-14-2011 11:04 AM

I was doing some browsing myself and like others here was unable to find an active link. Mikefocke had responded and said it was on his website too but it would be the same link anyway. Can someone give me a valid link for the DIY?

Also, I have some new information which may or may not be useful. Whether the car is off or on at full a/c, the pressure needle will always read that 150psi value. Not sure if that eliminates anything or makes something a bit more suspect.

Anyone think the expansion valve may be bad?

EDIT: I found the DIY on renn and I'm going to attempt the same fix. I'm not sure how this would actually fix my low side high pressure issue, but at least I can remove the rest of that irritating foam. I'm stuck at one of the earlier steps. I have provided a picture of what I am seeing here. I believe that on the DIY he is saying to remove the pieces where I have labeled as B, however I felt resistance and I'm not in the mood to damage anything. Anyone know how to separate the bottom side of the flap?

DIY: =http://www.renntech.org/forums/tutorials/article/121-fixed-my-lack-of-heat-problem-here-is-the-procedure/


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