Hissing sound from aircon

[megaclaw]

Hi,

I am a little irritated by the hissing sound recently when i turn on the air-con.
Seems like the air-con is working harder.
Is it due to lack of air-con gas?
Wondering anyone here has the same problem or is it normal?

 

[megaclaw]

Re: Hissing sound from aircon

I want to try topping up the aircon gas...
Can I go to any wkshop to ask them top up the gas?
Or BMW use different kind of gas. :ehhh:

 

[russo]

Re: Hissing sound from aircon

its a tell tale sign of leakage. Probably the evaporator coil is leaking. Have it replaced. Compressor, expansion valve and dryer are quite robust. Same gas, R134. If after topping up, noise dissappears, then its a leak. Good luck.

 

[megaclaw]

Re: Hissing sound from aircon

Thanks....looks like I am going to spend some $$$ repairing liao.

Another question: After I top up, if sound disappear and never come back, can I just live with it?
Or you think it is better to replace first.

 

[piggyboyz]

Re: Hissing sound from aircon

Depenging on age of car, top up might be necessary so if after topping up, the noise is gone, then u r alright.

If u get the hissing sound again, it will indicates there is lack of gas again and that will be a tell tale sign of a leak..

 

[DreamDriver]

Re: Hissing sound from aircon

If there's hissing sound but aircon still cold, could that also be due to not enough gas?

 

[piggyboyz]

Re: Hissing sound from aircon

If there's hissing sound but aircon still cold, could that also be due to not enough gas?

Well it might be that

-- the hissing sound is not from air con

-- the hissing sound is from air con but the just slightly under pressure so air con still cold

 

[DreamDriver]

Re: Hissing sound from aircon

Well it might be that

-- the hissing sound is not from air con

-- the hissing sound is from air con but the just slightly under pressure so air con still cold

But in my case

-- hissing sound seems confirmed to be from aircon cos when I off radio I can hear it very clearly, then when I off aircon it's gone

-- hissing sound has been there for months, so if it's not enough gas then unlikely that it's "just slightly" not enough

You think could be something else besides gas that is wrong with the aircon? I'm adopting the wait-until-it-spoils-then-see-how approach, you think that's advisable?

 

[megaclaw]

Re: Hissing sound from aircon

But in my case

-- hissing sound seems confirmed to be from aircon cos when I off radio I can hear it very clearly, then when I off aircon it's gone

-- hissing sound has been there for months, so if it's not enough gas then unlikely that it's "just slightly" not enough

You think could be something else besides gas that is wrong with the aircon? I'm adopting the wait-until-it-spoils-then-see-how approach, you think that's advisable?

Same problem here....I will top up the gas and see what happens.

 

[DreamDriver]

Re: Hissing sound from aircon

Same problem here....I will top up the gas and see what happens.

Thanks. Ya I know we have similar problem, that's why I posted in your thread. Hope you don't mind.

Difference is I think for you it just started recently, whereas for me it's been a few months already (could be close to half a year I think).

 

[megaclaw]

Re: Hissing sound from aircon

Update:

I went to top up my gas at a aircon workshop in Alexandra. The mechanic said that the aircon gas is already full.
He said the compressor has spoilt but I dun believe.

If the gas is full...this means no leakage.

So I called Performance and spoke to a advisor. He said that this could be due to the block valve is choked and asked me to send my car to workshop outside (My car warranty ended) for aircon servicing and change the block valve.

He said cannot be the compressor and the most probable cause is the block valve.
So now I suppose...I should send to a workshop. :thinking: hmmm

 

[megaclaw]

Re: Hissing sound from aircon

I went to another workshop recommended her.
They used a aircon gas top up system to drain the gas before top up.
Found that gas is quite empty.
This means the 1st workshop i went to try to con my $$$. :furious:

After top up...hissing sound disappear...but this also means somewhere is leaking.
Now crossing my fingers...hope the hissing sound dun come up else I will need to spend a lot more $$$$$$$ to trace the leak.

 

[DreamDriver]

Re: Hissing sound from aircon

Which aircon shop did you go to? Can post or PM me the address? Thanks!

 

[beem]

Re: Hissing sound from aircon

I am also getting a hissing sound...but only when I start the aircond when the car is cold..it hisses for a while then its gone...is this the symptom u are seeing as well?

 

[megaclaw]

Re: Hissing sound from aircon

Which aircon shop did you go to? Can post or PM me the address? Thanks!

PM you liao.

Hi Beem,
Starting up with hissing sound is okay lah i think....the gas is just passing thru your expansion valve.

 

[beem]

Re: Hissing sound from aircon

Thanks Bro...

Got me worried when u guys are saying hissing sound from aircond..Had enough of crazy sounds from my car liao..haha...

 

[megaclaw]

Re: Hissing sound from aircon

I went to another workshop recommended her.
They used a aircon gas top up system to drain the gas before top up.
Found that gas is quite empty.
This means the 1st workshop i went to try to con my $$$. :furious:

After top up...hissing sound disappear...but this also means somewhere is leaking.
Now crossing my fingers...hope the hissing sound dun come up else I will need to spend a lot more $$$$$$$ to trace the leak.

Hissing sound never come back...problem solved by topping up gas only.
Moral of the story: Never believe 100% what the workshop says

 

[yendor]

Re: Hissing sound from aircon

Bros, the hissing sound comes when the compressor is trying to build up pressure across the expansion valve. It is very normal for an automotive system to loose air-con gas as the rubber hoses and couplings leak very very slowly. If you top up air-con gas every 2-3yrs it is normal. In older cars that use complete hose systems instead of aluminium pipes and short lengths of rubber hoses (found in today's cars) the leakage can mean a top up every 1-2yrs. This is no reason to panic.

When the expansion valve is blocked, the in pressures rise very drastically compared to a very low out pressure. The shop that quoted the (compressor spoilt report) is very common. They will change everything and subsequently, vacuum the gas system and top up again, incidently solving the original problem and earning a big bill.

cheers

 

[megaclaw]

Re: Hissing sound from aircon

oic....great explanation....also gave me the peace of mind.

 

[kccheong]

Re: Hissing sound from aircon

hi, understand the explanation on the hissing sound... I had the sound in my car on 2 occasions about 1 month ago... it happened mid-trip, instead of on cold start up... would this be still a blocked valve? If so, will go down to PML and convince them to do the job, as my warrantee will be expiring in a couple of months...

KC