306 A/C Noise from behind dash

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razzleuk
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306 A/C Noise from behind dash

Post by razzleuk » 23 Apr 2005, 01:54

Hi,
Yesterday my 306 started making a quite nasty noise from behind the passenger side of the dash when the aircon is switched on. It sounds like a dry-rubbing metal-on-metal kinda sound which is making me nervous!
In the interest of experimentation, I left the aircon on for my 10 minute journey from home and it appears to be working albeit not very effectively. I have never had the system regassed (the car is '97 build) and its effectiveness has never been as good as other cars i have been in, so it may be working as well as it ever did.
Have I just run low on gas, or is something expensive on its way out?! Is the compressor behind the dash? There is no noise with aircon turned off..
Thanks in advance for any advice!
Raz.
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np
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Post by np » 24 Apr 2005, 01:22

The compressor is under the bonnet.Not sure about the noise.
A/CON usally needs a regass every 3-5 yrs.I had mine done 3 yrs ago now,but it still works 100%.I presume you would have a pollen/cabin filter?Has that ever been changed?It needs replacing at every service.It can become quite blocked up,reducing a/c output.Mine usally tends to not work as good when its coming up for a service,as the filter is dirty.I drive 6x6 Volvo dumpers at work with a/c.I`ve offten had 1 where the a/c isn`t very good.Clean all the dust out of the filters & it works great then.
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Post by rossd » 11 May 2005, 17:50

None of the 306's had a pollen filter (Very odd...)
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alan s
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Post by alan s » 12 May 2005, 03:16

If it has never been 100% efficient then chances are you have a problem (says he, stating the bleedin' obvious)[:D]
The noise possibly may be coming from the actual evaporator as the gas can get noisy when the level falls as it passes through the TX valve. Faulty valves in the compressor (leaky discharge valves) or a faulty T/X valve can also create noise if say the filter at the TX is partially clogged or if there is moisture in the system.
I suppose you could run through the system and replace the "O" rings, TX and filter dryer but at the end of the day, it will have to go to an air/con repairer to be evacuated and recharged and if the compressor is the fault, then the time and a lot of the parts you would have used may get replaced unnecessarily.
My suggestion would be to take it to an air/con repairer for a quote before you start and see if he can narrow the field down and either condemn or give a clean bill of health to the compressor.
BTW, when operating as it should, the systems on these cars is one of the best around.
Alan S
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razzleuk
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Post by razzleuk » 17 May 2005, 02:07

Thanks for the advice guys.
Alan: I have always been jealous of how efficient the aircon is on my brothers 206 - gives me a cold headache :-)
Have got a mobile guy coming out to look at it at the weekend, will let you know how I get on.
Raz.
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Post by razzleuk » 21 May 2005, 15:36

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by razzleuk</i>
Have got a mobile guy coming out to look at it at the weekend, will let you know how I get on.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
A few days after the noise behind the dash started the system refused to engage at all. As the fans weren't going either when the A/C was switched on, I presumed the ECU was consciously not activating the system due to low gas or a fault being detected.
The mobile guy has been this morning and pressure tested the system - it held 7 bar for 15 minutes so the pipework is good. He re-gassed it and it now seems OK. It all sprung into life so I'm hoping that it was just low gas that was the problem.
Having said that, he did comment that it wasnt as cold as some of them are, only dropping to around 6.4C. However, if it keeps working it's cold enough for me!
Raz.
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Paulmi16
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Post by Paulmi16 » 21 May 2005, 17:26

The aircon on our 306 is not as good as the aircon on our Ford Focus, but the temp inside the car when the 306 was re-gassed was around 4 degrees C
Paul.
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razzleuk
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Post by razzleuk » 23 May 2005, 04:09

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Paulmi16</i>


The aircon on our 306 is not as good as the aircon on our Ford Focus, but the temp inside the car when the 306 was re-gassed was around 4 degrees C
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Thanks Paul, useful information. I'm positive mine has never been as cold as other cars, I'll post back here with any news if it fails again!
Raz.
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alan s
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Post by alan s » 23 May 2005, 04:21

Don't want to be the bearer of bad tidings, but that temperature is about 2 degrees minimum above the normal acceptable maximum at the coil.
Pressure testing can't be done in 15 minutes. It is usually done over a 12 - 24 hour period and my suspicions would be that there could be another trip to the air/con man as soon as temperatures begin to rise during the summer.
It either is not fully charged, has a receiver dryer ready for replacement and needs a thorough checking for leaks with the entire system exposed for examination, or may even have oil up in the evaporator.
Did he run a vacuum pump on it before he began recharging? That's a thing like a small compressor that he would have connected via his gauges and run for at least 20 minutes?
Alan S
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Post by razzleuk » 24 May 2005, 00:18

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by alans</i>

Don't want to be the bearer of bad tidings...
Did he run a vacuum pump on it before he began recharging? That's a thing like a small compressor that he would have connected via his gauges and run for at least 20 minutes?
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Hi Alan,
Firstly thanks for your reply and advice :-) He did run a vacuum pump for about 20 minutes before refilling the system. He measured the amount of gas using a data book as a reference, (around 0.725kg if I remember correctly).
I did get the distinct feeling that he knew the temperature wasnt quite low enough and was indicative of a further problem. In addition he also added the gas as a liquid and not gas or something? Is that dodgy?! He said it would be quicker if "we could get away with it" but looking at his scales the correct amount (weight) went in.
The car is getting old now and I had said to myself that if it was anything more than a regass then I probably wouldnt bother on cost grounds. Since Saturday I read somewhere on some peugeot literature that the dryer needs replacing every 3 years, does this sound right?
Thanks again for your advice, I may drive around tomorrow with the temperature sensor device we have at work to double check the temps. This car had only done 9k miles when I bought it at 3 years old in 2000 so I am guessing it was stood for long periods of its early life which probably hasn't helped the seals either :-(.
Raz.
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alan s
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Post by alan s » 24 May 2005, 04:20

Yep, it's OK to "drop charge" in fact on car air/cons it is the recommended practice.
I always worry when a system needs regassing as they use gas to make them operate, not consume it like a stove does, and whilst a certain amount of permeation is acceptable, it usually comes on gradually over a few summers and not suddenly.
Access to the T/X valve seems to be something the repairers over there have an aversion to getting and it is most important as the majority of leaks stem from that region.
The receiver dryer has to be replaced mainly due to risks from contamination caused by undetected leaks or allowing the system to get totally out of gas and getting contaminbation in them and I would say the thought of replacing every 3 years isn't such a bad idea or precaution. It could be that the dryer is partially blocked which can cause this as will valves leaking internally in the compressor.
See how it goes; at least it's probably not as critical over there as it is over here with our combined heat and humidity, so you will probably be able to live with it.
Alan S
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razzleuk
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Post by razzleuk » 24 May 2005, 04:53

Cheers for all the info Alan, I will let you know of any further developments :-)
As I said earlier - this system has never been great and perhaps has got worse in the past few years; but it is hard to tell. (I did have an hours commute so it always had time to get quite cool for an hour twice a day).
From my general knowledge and having read your previous posts in this forum section, I am aware that the systems "lose" rather than "use" gas - I am just hoping that my leak is very gradual and as such can be tolerated for a couple of years without needing another re-gas! I fear a full investigation into the source of the leak by a garage at modern hourly rates wouldn't be economically feasible!
Cheers; you are a credit to this forum.
Raz.
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