Air con query, help needed!

[Bengi]

Hi guys I’ve just had my car in for a re-gas today which I’ve waited for since I collected the car, 

however it is noticeably cooler but strangely it feels more cool on the passenger side, both zones are set to LO, and I can hear a hissing from behind the steering wheel.

Hope someone can advise as to what is normal before I call them uk to have it looked at again. 

 

[TomsFocus]

Normal on Mk3 Focus...no-one seems to know why!  Cooler on the NS is a pretty much daily complaint on the Mk3 Facebook page.  

[Bengi]

Guess I’ll have to accept that then, just the hissing to solve now 

[bronc]

Maybe because that's the driver's side on RHD cars 😄 

[Bengi]

Drivers side is on the RHD

[TomsFocus]

45 minutes ago, Bengi said:

Guess I’ll have to accept that then, just the hissing to solve now 

Is it a loud hissing or just about noticeable with the radio off?  There will be a bit of noise from the gas movement in an AC system, same as when the motor kicks in on your fridge.

41 minutes ago, bronc said:

Maybe because that's the driver's side on RHD cars 😄 

Umm...it isn't!   Think you mean LHD.  

[bronc]

Oops, LHD, yes.

[Bengi]

Can just about hear it when the radio is on but very noticeable when off 

[Bengi]

I must add the noise is noticeable from the moment I press the AC button and does not stop

[michaelburrows]

Yep .sounds like mine waz???i took to fords for my air con service and it feels the same on both sides now. I asked them y passenger side was cooler. They had no idea. But as i say after service it seems just fine. 

[iantt]

9 hours ago, TomsFocus said:

Normal on Mk3 Focus...no-one seems to know why!  Cooler on the NS is a pretty much daily complaint on the Mk3 Facebook page.  

I didn't know others had this issue. Mine is the same. 

[Bengi]

I have another update guys, on driving home from work this evening I was playing about with the controls, the hissing is constant as soon as the AC button is pressed and will only stop when it is turned off.

more importantly when messing abit with AC on or off I can feel little to no difference in temperature at the driver side vents. 

Could the hissing be linked?

 

[Bengi]

Iantt are you saying you also have the same issue or that bith vents feel the same?

[iantt]

My driver's side vents are not as cold as the passengers side. 

[Bengi]

Only slightly or? Tonight I couldn’t tell a difference between air con and no air con on driver side 

[Bengi]

Is there a method to reset or re-calibrate the system? Unsure of this is needed

[TomsFocus]

Interestingly, it doesn't seem to matter whether you have a Titanium/TX with dual zone electronic climate or a Zetec/ZS with fully manual controls, both get the same issue.  So that should rule out any of the sensors or even the HVAC box itself.  I have wondered if it's simply because the hot heater matrix/pipes are closer to the drivers side vent ducting on the Focus.

As far as I know the system isn't 'smart' enough to be recalibrated even with the DZCC, and if you're using 'LO' rather than a specific temp then there is no temp control anyway, just max cooling.

Not sure what to suggest about the hissing though...some noise is normal from the AC but can't really say whether yours is extra loud without hearing it in person.  Does it hiss with high fan speed as well or is it just with the AC on?  I assume you can't smell AC gas lol?

[Bengi]

Thanks for the reply toms, it can be heard on any setting as long as the AC is on, today when using the car the passenger side which was coolest yesterday is starting to feel warmer too, so I’m thinking the hissing is a leak behind the dash somewhere as it’s gradually getting worse, the car is booked to be looked at on Monday. I can’t smell anything however.

[Botus]

On ‎7‎/‎26‎/‎2018 at 10:22 PM, iantt said:

My driver's side vents are not as cold as the passengers side. 

on many cars they have the sides are cooler than the centre...  in all the silly heat we've been having I just worked out where this lunacy is likely to come from.  I guess some idiot felt heat soak means the sides need more cooling.  For the last 20 years all I get is one arm at the right temp and tepid ***** coming out the middle.

may be the hoses could be swapped over to achieve that silliness rather than left and right are muddled?

 

 

[mastachaz]

On 7/26/2018 at 12:36 PM, bronc said:

Maybe because that's the driver's side on RHD cars 😄 

i think you might be right 🙂 car its design fir left hand not right 🙂

[Bengi]

ok, so it appears that hissing has definitely been a leak from behind the dash somewhere, as it has stop today and low and behold no chilled air from any vent.

[TomsFocus]

20 hours ago, Bengi said:

ok, so it appears that hissing has definitely been a leak from behind the dash somewhere, as it has stop today and low and behold no chilled air from any vent.

Oh dear, if there is a leak behind the dash it'll be a right pain to fix.   You're also not really meant to breathing in AC gas lol, surprised you couldn't smell it though, it's a very distinctive smell.

[Bengi]

Nope I didn’t notice any smell out of the ordinary which as you say seems strange, I’m still assuming it was a leak being that it’s stopped and that we have no chilled air now, 

also do you know which components are behind the dash? I’ve looked around engine bay and seems to be primarily pipe work. 

[Tdci-Peter]

3 hours ago, Bengi said:

Nope I didn’t notice any smell out of the ordinary which as you say seems strange, I’m still assuming it was a leak being that it’s stopped and that we have no chilled air now, 

also do you know which components are behind the dash? I’ve looked around engine bay and seems to be primarily pipe work. 

The only parts of the a/c system inside the car cabin are the expansion valve, evaporator, and a couple of pipes, all buried deep in the heater unit in the middle of the area well behind the dash. Most of the system is the other side of the bulkhead, in the engine bay.

The amount of refrigerant in an a/c system is really quite small, an audible leak would only last a few minutes before most of the gas was gone. Also the system remains pressurised even when off: At 25C, R134a needs about 80psi to stay liquid. So it would continue to leak all the time.

So it could be there was a slight leak somewhere, maybe the fill valve did not re-seal properly after the re-gas. The hiss could have been a symptom of low gas pressure, along with the poor cooling, and now there is not enough pressure to trigger the a/c low pressure switch, so it has stopped working.

Contamination in the gas (eg air) can also cause a hiss. So there is some questions about whether the re-gas was done properly. Also if the car is only 3 years old, there is some suspicion about why it needed a re-gas at all. My 12 year old car has had a just trace of gas added in the last 7 years, and the a/c is still working. Normal leakage rates should be very small.

[Bengi]

Just thought I’d update the thread with the result, car was in for repair and it was found the condenser had a leak on a joint so the whole unit has been replaced, this has eliminated the hissing and also the air con is icy cold on both sides without a noticeable difference . 

Very happy with the outcome.