Air conditioning issues/observations - 986 Forum

ScottAZ · 08-08-2018, 06:51 AM

Hi all, my new to me 02 S has been great, but the AC seems a little weird. In full disclosure, I'm in Phoenix and it's been above 110F for quite some time now, so we're talking about extreme conditions. Here are my observations:

When the compressor is on, it makes a surging sound. Sort of a slow low to high sound in the background. There is no variance in the engine revs in correlation with this surging sound.

Above 3K RPM or so, the compressor seems to shut off and I'll get blast of warm air after a hard acceleration. A noticeable whoosh sound is present once the acceleration has leveled off and the air blows cold again.

The AC is much colder when the car is at cruising speed than when idling, even when just stopping at a red light after the car is fully warmed (cooled) up. At cruising speed, it's nice and cold, but when puttering around in stop and go traffic, it's warmer.

In our extreme heat, the AC is barely passable. I understand a black soft top is hardly ideal at rejecting heat, but given that the cabin is so small, I'd expect it to be able to cool it easily. Maybe I'm asking too much of a 16 year old car in the insanely hot desert. Are any of my observations out of the norm? Thanks!

paulofto · 08-08-2018, 07:14 AM

It sounds to me you have possibly one of 2 issues. Or maybe both. 1) The expansion valve might not be releasing enough refrigerant into the evaporator when at low RPM due to low pressure. 2) you are low on refrigerant.

The expansion valve can 'freeze' in a closed, open or partially open position. I'd get an A/C guy to look at it. The valve is about $30 CDN and refrigerant about $60 CDN. That is what it cost me to fix my similar issue a couple of years ago.

A far more expensive problem may be the compressor itself or the compressor clutch not operating properly.

ScottAZ · 08-08-2018, 07:39 AM

Quote:

Originally Posted by paulofto

It sounds to me you have possibly one of 2 issues. Or maybe both. 1) The expansion valve might not be releasing enough refrigerant into the evaporator when at low RPM due to low pressure. 2) you are low on refrigerant.

The expansion valve can 'freeze' in a closed, open or partially open position. I'd get an A/C guy to look at it. The valve is about $30 CDN and refrigerant about $60 CDN. That is what it cost me to fix my similar issue a couple of years ago.

A far more expensive problem may be the compressor itself or the compressor clutch not operating properly.

Thanks! Is the expansion valve replacement something I can DIY without too many specialized tools? If I'm low on refrigerant, does that indicate a leak? I wonder if it would make sense to try one of those pressurized cans of refrigerant to see if that helps. Can that hurt? Thanks again!

ndfrigi · 08-08-2018, 08:12 AM

Hi, pls don’t use the freon refill from can. Just go to an AC shop and ask them to check the refrigerant pressure. Not expensive for adding some freon only.

ScottAZ · 08-08-2018, 08:16 AM

Quote:

Originally Posted by ndfrigi

Hi, pls don’t use the freon refill from can. Just go to an AC shop and ask them to check the refrigerant pressure. Not expensive for adding some freon only.

OK, thanks. Do our cars use Freon? Not R134?

paulofto · 08-08-2018, 08:18 AM

Quote:

Originally Posted by ScottAZ

Thanks! Is the expansion valve replacement something I can DIY without too many specialized tools? If I'm low on refrigerant, does that indicate a leak? I wonder if it would make sense to try one of those pressurized cans of refrigerant to see if that helps. Can that hurt? Thanks again!

Personally I'd go to the A/C guy for any repairs. The system needs to be drained to replace the valve and a vacuum needs to be drawn to refill it so somewhat special equipment is needed. They can test the system for leaks at the same time. They can also diagnose if it isn't the valve and something more serious.

When I had mine done the A/C shop did not have a valve for my car so I got one from ******************************** and the A/C shop only charged me labour and the cost of the refrigerant. Here is a link to the ******************************** part

https://www.********************************.com/en/catalog/porsche,2003,boxster,3.2l+h6,1417924,heat+&+air+conditioning,a/c+expansion+valve,6788

You could get a A/C refill kit and try charging the system yourself. If that fails then go to the A/C shop. I assume in Arizona A/C repairs are very common.

The place I got mine starts with 'roc' then 'kau' then 'to'

PS looks like I can't post the site where I bought one. Here is the part number . . . 996 573 929 01 expansion valve

ScottAZ · 08-08-2018, 08:25 AM

Quote:

Originally Posted by paulofto

Personally I'd go to the A/C guy for any repairs. The system needs to be drained to replace the valve and a vacuum needs to be drawn to refill it so somewhat special equipment is needed. They can test the system for leaks at the same time. They can also diagnose if it isn't the valve and something more serious.

When I had mine done the A/C shop did not have a valve for my car so I got one from ******************************** and the A/C shop only charged me labour and the cost of the refrigerant. Here is a link to the ******************************** part

https://www.********************************.com/en/catalog/porsche,2003,boxster,3.2l+h6,1417924,heat+&+air+conditioning,a/c+expansion+valve,6788

You could get a A/C refill kit and try charging the system yourself. If that fails then go to the A/C shop. I assume in Arizona A/C repairs are very common.

The place I got mine starts with 'roc' then 'kau' then 'to'

PS looks like I can't post the site where I bought one. Here is the part number . . . 996 573 929 01 expansion valve

I guess the forum didn't like your links! It's OK, I can figure it out.

I can't seem to find an AC specialist and don't like the idea of taking it to one of the Porsche shops, as they seem to be pricier. Do you think something like this could be safely handled by a Jiffy Lube or Firestone type place? Thanks!

thstone · 08-08-2018, 09:07 AM

Quote:

Originally Posted by ScottAZ

I can't seem to find an AC specialist and don't like the idea of taking it to one of the Porsche shops, as they seem to be pricier. Do you think something like this could be safely handled by a Jiffy Lube or Firestone type place? Thanks!

Any place that services A/C systems can do it. There isn't anything unique about a Boxster A/C system.

With that being said, choose a service shop where you have confidence in the work being performed. Sometimes you do get what you pay for.

ScottAZ · 08-08-2018, 12:27 PM

Well, I’m sitting at this little AC shop now. It seems he’s really only in the business of selling recharges, but the reviews were good. He said the pressure readings were a bit low so he said the first step is to flush and recharge the system. That will lighten me by $85, so we’ll see what happens. Hopefully that does the trick.