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Discussion Starter #1
I've just noticed a "Shushing" noise which seems to be coming from the a/c pipes in front passenger side dash area (RHD car) and it can be heard from same area under bonnet/frunk/hood. It seems to dissipate when the fan OR the a/c is turned off. Can't say I've ever heard anything like it before, does anyone else's Cayman do it?
 

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You should have the refrigerant charge checked. A slight undercharge can make the system make sounds like that as the refrigerant flows thru the expansion valve to the evaporator. (bubbles in the liquid refrigerant.) It is not real unusual for a low charge to be more noticeable in colder ambient temps. Almost could be considered normal.
 

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Discussion Starter #4
Many thanks for all the replies. Where is this dryer?
 

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I've been noticing a weird noise in my 987.2 Boxster S, too, and trying to pin it down. It's really hard to describe the sound- something between a whistle, gurgle and warble. Maybe a little like the warble while tuning an AM radio, and happens most often upon deceleration. It sounds like it's coming from behind me, though, not the dash. Is my noise the refrigerant or something else?
 

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Many thanks for all the replies. Where is this dryer?
The dryer is mounted in the cavity uner the platic cover in the front trunk where the battery is in front of the driver. It is right next to the horn. If there is a refigerant leak there will be some oily residue.
 

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Before you go parts chasing and change out the dryer, you might want someone with some automotive AC knowledge check to see if that's where the leak is. There are lots of parts and connections involved with AC, so it doesn't necessarily have to be the dryer where the leak is (although it might be a good candidate since others have had the same issue). The first thing to check is to see if your car is low on freon. If it is, then you've probably found your noise source and you'll need to find the cause of the leak. AC auto techs can add a dye to help expose the source of the leak.

I saw Edd China do this once, so maybe you can chase him down for some assistance.
 

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Before you go parts chasing and change out the dryer, you might want someone with some automotive AC knowledge check to see if that's where the leak is. There are lots of parts and connections involved with AC, so it doesn't necessarily have to be the dryer where the leak is (although it might be a good candidate since others have had the same issue). The first thing to check is to see if your car is low on freon. If it is, then you've probably found your noise source and you'll need to find the cause of the leak. AC auto techs can add a dye to help expose the source of the leak.

I saw Edd China do this once, so maybe you can chase him down for some assistance.
Good advice. AC-- refrigeration repair is not just parts changing. One note though--- I do not like putting dye in the systems. One can usually find a leak with a leak detector and soap bubbles. If it is oily around the dryer fittings where the lines bolt down, that would be a good place to start checking with soap bubbles. AC on and compressor running so that pressure there on the high side is at operational levels. IF a leak is found though and one wishes to open the lines, he must be prepared to evacuate the system before he recharges it after changing the dryer. Moderns systems are very critical on charge too. Weghing in the precise amount of refrigerant is advisable. It is possible to fine tune the charge with teperature and pressures but most techs rely on simply weighing in the precise amount.
 
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