noisy aircon

[snapper65]

for a while now Ive been perplexed at what a noisy place the cabin of my cayman s is. What with the rattling boot and the sound of what I assume is the belts whirring like a not-too-distant gale, its quite hard actually to hear an engine note at low speeds. Today a revelation - for reasons unknown I switched off the climate control and.... quiet. The OPC where I bought the car said just to leave it on all the time to keep cabin temp constant. When the climate is off I can actually hear the engine note below 3000rpm . With the climate on, even at lowest setting, there is a mechanical rumble, like the sound of far-off agricultural machinery, coming from the bonnet area, I think drivers side

Can I make the following assumptions?
1) its not normal
2) its likely to be the aircon unit
3) its covered under warranty

[sportsandclassic]

Hi, normally noise in the airconditioning system is down to not enough refrigerant inthe system... It may have a leak somewhere or need a regas.

You can normally hear it through the ventillation system when you have low refrigerant as it grumbles and when turned off the noise goes away.

Mike

[snapper65]

Thanks Mike, that does sound like it. Only had the car four months. Much as I like the car, I am less and less impressed with the much vaunted OPC preparation.

[6C4GTS]

If its the aircon leaking the noise will eventally stop as the gas level reaches the low level and the system cuts the compressor out - as happens when you switch off in the cabin. A struggling compressor - due to low gas - sounds whiney. I assume the compressor is in the engine bay on a Cayman just like a 911.

Aircon leaks are part of ownership - mesh in the front will limit this to an extent.

A good aircon guy - not kwikfit or any other drive in - will pressure test your system and tell you in 5 minutes if you have a leak and if so where it is - condensors or pipework.

[snapper65]

Hmm. Does sound whiney, but the noise does seem to be coming from forward of the cabin. Will take the car to Bristol OPC for a look-see. They seem reasonable so far, and weren't responsible for the initial prep. I accept these things are part of ownership but I can't help wondering, there are so many little niggles I wonder how much more than an oily rag wipe down the supplying OPC actually did