S40 T5 2005 Aircon constant hiss, new member please help

[salsal]

Hi Everyone,

New to the forums and have just bought a volvo s40 T5 from a dealer the other day.

Now I have 2 issues. Other than that the car runs like a dream
When I start the car you can hear this hissing sound, like an aircon hissing,(aircon is off at this time) From the dash. This stops after about 10 seconds and doesn't hiss again.
Now when I turn the AC on, the hiss comes back at a constant rate, sometimes being louder than other times when the compressor clicks.
Cold air is still coming out, but this hiss is really annoying.
I have a fair knowledge about cars and find this to be puzzling, Might be low on freon, who knows.

The second issue is changing gear and a slight clunking when engaging first and second gear, this is on a 6 speed manual.
I thought it might be a transmission mount but not sure.
Could be a normal part of the drive train on these cars.
Putting the car into first when its cold started takes a smidgen of effort but read that this may be normal. When the car is slightly warm it's much easier to change gears.

Any insight would be very helpful.

Many Thanks guys and keep rocking.
Sal
Sydney Australia.

[salsal]

Guys, anyone please???

[iainmd]

I'd say the stiff first and second gear select is quite normal. Mine's the same when cold but eases off when it has warmed up a bit.

As far as the aircon noise goes I can confirm that it isn't normal but I've no idea what the problem is. I'm no expert on the mechanics of an air conditioning system. Mine's as quiet as you'd expect.

Cheers,

Iain

[salsal]

Originally Posted by iainmd

I'd say the stiff first and second gear select is quite normal. Mine's the same when cold but eases off when it has warmed up a bit.

As far as the aircon noise goes I can confirm that it isn't normal but I've no idea what the problem is. I'm no expert on the mechanics of an air conditioning system. Mine's as quiet as you'd expect.

Cheers,

Iain

Hey Thanks heaps!

Also I asked the dealer about the cloudy brown water in the radiator expansion pack, he will be doing a system flush.
When you change gears do you sometimes hear a little clunk, not a crunch, but a clunk . LOL
They are going to regas the aircon and see if that fixes it..anyone elses input would be great.

Please!

[Welton]

Your car sounds the same as mine apart from the "hiss".

I'm currently looking into my gear change woes and will be changing the gear oil for some Silkolene stuff next week (a thinner grade) will report back then!

I had a brown/orange sludge in my expansion bottle and the dealer cleaned it out but insisted the coolant was fine (it's green and clear) however I am getting it flushed and treated next week with flush agent, antifreeze and conditioner.

Most a/c systms can make a hiss sound sometimes more than others depending on the outside temp - it's the sound of the high pressure refrigerant passing through the expansion valve in the evaporator. I'd be more worried if the compressor sounded grumbly or was running all the time instead of cycling on/off (indicating low gas).

[iainmd]

Originally Posted by salsal

When you change gears do you sometimes hear a little clunk, not a crunch, but a clunk .

Please!

Not really, no. I can't say I've noticed any abnormal noises for the gearbox. Sorry.

[Guru]

Gears are stiff on the first run of the day, especially 2nd gear, can confirm that too, i tend to shift from 1st to 2nd slowly and carefully when cold letting it slip in by itself, not dragging it in to position. no cluncking though.

Never heard a hiss either.