Hotter than 7 hells

Ok gents, having some A/C troubles and just wanted to pick your brains. The aircon in my 99 is intermittent at best. Not icy cold by any means but tolerable at times but mostly just downright crappy. The heater sucks too. Firstly, the compressor kicks on just fine so I am hoping I can eliminate that from the scenario. The system is charged with R32 so that's out too. Now, when I bought the car last year sometime the aircon wasn't icy but it was fall and I didn't notice. I had the foam blowing from the vents so I took the flap out and recovered it. That solved the foam issue but not temp. I just don't know where to start diagnosing this. Bad heater core? What the hell could I have reinstalled wrong? Just a bit frustrated when it's 100 degrees out!

I'm no expert but does the compressor have a clutch that could be bad? AC radiator freeze up?

Well, I don't know. I do get cool air at times so I was figuring the compressor might be ok. Plus, it's only two years old. If it helps, it cools much better when car is in motion. Sitting still it's like an oven. Not sure if that will help further diagnos. Also, there are two coolant lines that feed the heater core. I assume this is all plumbed to the rest of the cooling system? I did lose a little coolant when I pulled the hoses off but I can't see that being an issue. Could I have air trapped in those lines? Grasping at straws!

Sounds like bad radiator fans or fan relays to me. My 996 had the same symptoms when my fans failed.

Interesting lead. Thanks Dennis! Do the rad fans run all the time when the aircon is on? I'm always in the cabin and never really noticed.

Second what Dennis said. The rad fans are on low whenever the a/c is on, unless the engine is very hot then the fans will be on high. Turn on the a/c and then put your hand on the ground about 1 foot right in front of the front tires, you should feel air blowing down toward the ground. Check both sides and feel if they are similar.

I will take a look in the morning. I was just reading about the fan relay failures. We may be on to something here.

I hope that's it. The fact that your A/C works better when moving makes it seem like fan failure is a plausible explanation. The relays can fail, but the fan motors can fail also (which was the case for me). There are brushes in the motors, and they do wear out in time. The fans should run whenever the A/C is on, as mentioned above. My first symptom was poor A/C in hot weather. This was followed by rising water temperature, especially when idling in traffic or driving slowly.

Well, if it's the radiator fan or fan relay he must have noted some changes in the water gauge. Gator, have you? BTW, some time ago I changed my right side radiator fan resistor. It was bad. That may be another culprit. I have a thread on it here: https://rennlist.com/forums/996-foru...-resistor.html

Water temps are perfect, even sitting in traffic. If it's not the fans, I am an leaning towards a servo. Maybe I hooked it back up wrong and the door isn't operating properly and mixing hot and cold.

This might help? https://rennlist.com/forums/996-foru...outside-2.html Another big problem is that there is a total of 4 (FOUR) different flaps in the ventilation system . All of these will lose the foam eventually! I know the other 3 are not that critical, but still they will leak through making the ventilation less effective. For example, when you want to defrost the windshield, some air will seep through to the floor vents. The door distributing that should look like this:

Did you do the recharge of R32 yourself? If so you might have overfilled it, which will cause the compressor to shut itself off in order not to burn out.

At the risk of screwing up an actual real technical thread with silliness, is Mrs. Gator in the car when it's hot in there? On a serious note, seems odd that airflow helps the AC stay cool (when on highway), yet you are not noticing an increase in water temp when sitting still. The cool AC on the highway would indicate an airflow issue (lack of airflow from the engine cooling fan over the AC condenser), but an airflow issue over the AC condenser should also result in an increase in water temps when not moving (lack of airflow over the radiators as well as the AC condenser).

How do you know the system has the proper charge? Your symptoms sounds like a system with a low charge or alternately a cooling issue. If it was only the fans not turning on, operation while on the highway should pretty much be normal.

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My advice would be to start with a full evacuation of the system then hold the system at a good vacuum for the required amount of time to check for any leaks. If there is a leak then of course this has to be found and fixed and the system checked again. Afterwards the proper amount of refrigerant -- this is based on weight IIRC -- and compressor oil is returned to the system. Then the system is tested. There is a chart in the factory repair manual that for a range of ambient temperatures gives what the air temperature from the center dash vent should be for a properly functioning A/C system. If this temperature is not correct then possibly a problem with an air flap needs to be considered. You might try the various air vent control buttons to see if selecting one has either too much or too little air coming through it. However, the problem could be with the flap that routes some A/C air through heater core. If this is not working properly too much air could be routed to the heater core and of course the A/C would appear to not be working properly. (The test I mentioned above is done at Max cool which should have no air routed to the heater core.) Checking the fans was a good idea. However, I had a radiator fan in my Turbo fail -- the fan motor shaft snapped -- and the A/C and the coolant were just fine with one radiator even though I was in 90F+ heat in central CA valley (Fresno area). Thus it would be my opinion that only if both fans were not working properly could this affect A/C operation. At some point it could affect coolant temperature too if one spent some time stationary with the engine idling. But the first thing affected would likely be the A/C system.

Here is an update. Both fans are working on high and low. The servo is moving the large flap in the heater core. I had one of those all in one R32 refill cans and I put that on the low pressure side. I didn't add any but the built in gauge was in the red. Perhaps there is too much in the system. It cooled fairly well while in the shade of my garage. I will have the system evacuated, tested and refilled. Or, I can move to British Columbia or someplace with not so hot summers.

Did you mean R134A? I've not seen any R32 refill cans here in CA. When you connected the can to the low pressure port, was the compressor running? If it's not, it's just the natural pressure inside the system when the system is off, about 60psi (normal) and that may make the gauge go to red as the normal charged pressure is around 30-40psi when the comperssor is pumping.

R134...it's hot out. The compressor was running when the gauge was in the red.

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It's smokin' hot here this year Gator. Just saw 40C (104F) a couple of days ago in Osoyoos, BC. Interesting thread because my ACs also a bit anemic, at least at those temps. Hope you can find the answer. From the Weather Network: Monday, June 29, 2015, 7:31 AM - The last weekend in June felt like fall in Ontario, Quebec and the Maritimes. But out west, in British Columbia in particular, it was hot enough to bury records dating back more than 100 years. Back-to-back blazing hot days over the weekend saw 34 records topple on Saturday June 27, with another 30 following suit on Sunday June 28. Not only was the 40oC barrier broken in 2015 for the first time that weekend, some communities not only had their hottest days in June, one had its hottest-ever day, period, in 114 years. Hottest day ever There has never been a hotter day in Cranbrook, B.C., than it was on June 28, 2015 -- at least not since records were kept. The town made it to 36.8oC, a smidgen higher than its old record in 1925, and the hottest day it has ever experienced, in any month, since record-keeping began in 1901 -- at a time when Canada had only seven provinces. Though it's the only community that could make that claim, others, aside from experiencing their hottest June 28 on record, also marked their hottest-ever June days.

Update: well, I evacuated the system and refilled. It seemed to be cooling fairly well until I took it out for a spin to cool the engine down some from having it idle. Anyhow, there was a new whine coming from the engine bay while driving. Turn off the aircon and the whine stopped. Not sure why I didn't hear it while it was idling and even when I applied some throttle. So, perhaps the compress is on the way out. It was replaced about three years ago at the dealer by the PO. Hopefully that is the issue and even more hopeful that the dealer honors their lifetime parts and labor ad.

Oh, so we are back to my initial assessment.

Indeed sir.

Sounds to me as if your sun radiation sensors might not be working... using some sort of dash cover? What is the system like in recir, MAX cooling setting, de-select windshield airflow...?? That should bypass the "re-heat" function, no chilled airflow diverted through the heat core. Some car's engine ECU will disable the compressor if the engine coolant is "tending" toward overheating. Don't think my '99 did that, but.... Our '99's DS condenser/radiator fan failed in August in Mid-AR years ago, engine temperature started climbing.... Turned off A/C, rolled windows down..... HOT.... thinking. Turned the A/C back on, windows up, MAX cooling/recirc, drove home.

Which solar radiation sensors are these? The ones on the port warp nacelle, or the starboard?

Final update. I had the compressor and drier replaced. The drier was completely filled with debris as were the lines. Whatever the hell happened it was grandiose. I replaced all of the pulleys since they had never been done to my knowledge and a new serpentine belt. Drove home in 104 degree heat index with not a drop of sweat. I can now enjoy the summertime in a 996.

How much?

Well, I bit the bullet and used the dealer. I know, I know! But, my DD was also in the shop so I needed a loaner. Renting a car for the week would have cost me more. So, all in it was a hair under 2k. Good news is that the parts and labor are guaranteed for life. The tech warned that there still may be some metal flush through the lines but they will revisit any issues for free. The compressor itself was 779.00 new from Porsche.

Thanks Gator, I'm in the next car on that train.

There were a lot of incidentals like R134 and such. Labor was the biggest chunk. An Indy would probably have been cheaper but no lifetime guarantee. I hope yours isn't as extreme and is cheaper on labor. The tech spent quite a bit of time flushing the lines out.

Can you please tell us about the dealership's barista, though?

My dealer only has a Keurig machine in the waiting area. I guess I'm missing out on the proper Porsche dealership experience.

Like Dennis, the Barista was named Keurig. But, I did get to watch Hurley Haywood take his dog out for a poop so I have that going for me.

I have similar problem. Here in Houston, temperature + humidity make it hotter than 9 hells. I guess I'll have to bite the bullet as well. I've had the foam issue for a year and it pretty much seems to have run its course. I looked over the DIY refoaming the door, but not sure if that's going to help at all. Dealership time ahead, according to my revolving crystal Porsche ball...

These things never fail in the fall. It's always in the summer!

Is the deteriorating foam that big of a deal?

After I repaired the foam flap two years ago, the ac did function better. I probably had the underlying issue of a slowly dying compressor during that time until it finally killed itself. But, there was a big difference between foam and no foam.

Lifetime guarantee? I find that hard to believe. But I wish you the best of luck! There has to be some small print!!

No fine print. Brumos Porsche offers a lifetime parts and labor guarantee. It is what it is. Except for tires.

You can't place a price on comfort IMO. You can at least move on. I learned the hard way when it was time to buy a mattress. Went through two crappy ones before biting the bullet for an expensive one. Besides the Barista, did you at least get a good loaner?

I got a new Cayman S loaner. Very impressive little car. I must say that all the PDK bashing from the purists is BS. It is downright awesome. The very best part of the car? Ventilated seats! Sweet Jesus, where has that been my whole life?

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FWIW, I like PDK and ventilated seats myself. Now if they could have a shiatsu massaging option installed into the seats on top of the ventilation, that would be **** but I'm sure that would be at least a $5k option.

As nice as that 2015 was, I found myself missing my little 996 after the second day. I worried if he was making friends with the other Porsche's, was he bullied for being a redhead? When I pulled into the service bay and saw him sitting there, all was right in the world. Now, had that Cayman had a massage system in the seats I would be owning it right now and kicking that poor 996 to the curb for not being worthy.

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I have PDK and ventilated seats on my Macan and love it, love it, loooove it!