Squealing noise when using A/C
06-03-2003, 04:30 PM
#16
Addict
Rennlist Member
Rennlist Member
Join Date: Jun 2001
Location: Dana Point, CA
Posts: 2,537
Likes: 0
Received 0 Likes
on
0 Posts
Hey Eagle,
To be honest, I'm having a hard time thinking of a logical (to me) direct link between the A/C system and your interior fan control. That is, the volume of your hiss/squeal seems to have a linear relationship with interior fan speed (which would suggest a motor bearing). As you stated in your first post of this thread: "When I turn the speedknob to 2,3 and 4 : the hiss/squealing sound gets louder." I'm not an A/C tech, but it seems strange to me that the flow of refrigerant (assuming that's what's causing the squeal/hiss) is immediately responsive to interior fan speed (which would influence system load). Perhaps an A/C pro would know if this is plausible--that is, adjusting interior fan speed translates immediately to load on the A/C system?
Since you're describing the sound as also being a hiss, it doesn't seem like a noise a fan motor bearing would make. Which would suggest an A/C issue.
It will be very interesting to find out if a low A/C charge is the source of your squeal/hiss. I think you're taking the right approach by addressing the A/C's charge first. You gotta' have A/C that works, so in restoring your A/C, you can either confirm that it was the source, or remove it from the list of possible causes.
For the record, the A/C condenser is in the left-front fender (in front of the wheel).
Do keep us posted on what you find.
To be honest, I'm having a hard time thinking of a logical (to me) direct link between the A/C system and your interior fan control. That is, the volume of your hiss/squeal seems to have a linear relationship with interior fan speed (which would suggest a motor bearing). As you stated in your first post of this thread: "When I turn the speedknob to 2,3 and 4 : the hiss/squealing sound gets louder." I'm not an A/C tech, but it seems strange to me that the flow of refrigerant (assuming that's what's causing the squeal/hiss) is immediately responsive to interior fan speed (which would influence system load). Perhaps an A/C pro would know if this is plausible--that is, adjusting interior fan speed translates immediately to load on the A/C system?
Since you're describing the sound as also being a hiss, it doesn't seem like a noise a fan motor bearing would make. Which would suggest an A/C issue.
It will be very interesting to find out if a low A/C charge is the source of your squeal/hiss. I think you're taking the right approach by addressing the A/C's charge first. You gotta' have A/C that works, so in restoring your A/C, you can either confirm that it was the source, or remove it from the list of possible causes.
For the record, the A/C condenser is in the left-front fender (in front of the wheel).
Do keep us posted on what you find.
06-03-2003, 05:43 PM
#17
Pro
Thread Starter
Hi Randall,
thanks and with pleasure I'll keep you guys up to date. Probably after June 23rd.
Greetz.
thanks and with pleasure I'll keep you guys up to date. Probably after June 23rd.
Greetz.
06-23-2003, 06:23 PM
#18
Pro
Thread Starter
Update:
So I have brought my car to the OPC and they found out that there was only 10% left of the freon gas. There's a leak under the dashboard in a pipe near the evaporator. It's behind the astray. You can see it if you remove the astray. It would cost a whole lot of money to repair this, they told me. They have to remove the dashboard! (is this true?)
So I choose for a recharge.
The sound is gone because the system has 100 % freon again.
Greetz
So I have brought my car to the OPC and they found out that there was only 10% left of the freon gas. There's a leak under the dashboard in a pipe near the evaporator. It's behind the astray. You can see it if you remove the astray. It would cost a whole lot of money to repair this, they told me. They have to remove the dashboard! (is this true?)
So I choose for a recharge.
The sound is gone because the system has 100 % freon again.
Greetz
06-23-2003, 07:44 PM
#19
Dear Eagle, I'm afraid of your leak.
How much time elapsed from your last recharge ?
Reading your posts, I was suspecting about worn fan bearing, my Audi had a similar problem: squeaking sound only with AC on: the bearing was "cold-sensitive" and was squeaking only when in cold air.
And... Randall's question: where does the fan draw air from ?
In these days I'm spending some time on my climatic system.
Today I cleaned (by myself) the condenser, in left fender, with a light solvent and a lot of water. Found: dust, insects, leaves, needles of pine.
I'm planning an "evaporator cleaning day".
How much time elapsed from your last recharge ?
Reading your posts, I was suspecting about worn fan bearing, my Audi had a similar problem: squeaking sound only with AC on: the bearing was "cold-sensitive" and was squeaking only when in cold air.
And... Randall's question: where does the fan draw air from ?
In these days I'm spending some time on my climatic system.
Today I cleaned (by myself) the condenser, in left fender, with a light solvent and a lot of water. Found: dust, insects, leaves, needles of pine.
I'm planning an "evaporator cleaning day".
06-24-2003, 12:47 AM
#20
Addict
Rennlist Member
Rennlist Member
Join Date: Jun 2001
Location: Dana Point, CA
Posts: 2,537
Likes: 0
Received 0 Likes
on
0 Posts
Hey Eagle,
Thanks for keeping us posted. Very interesting to hear that the recharge cured the hiss/squeal.
Unfortunately, replacing the evaporator is a big job. An evaporator leak is high up there on my list of most feared P-car repairs. I have found an outfit that sells aftermarket evaporators at a nice price ($178). Never purchased from them, don't know anyone who has. But, I'm willing to give one a shot, if my evaporator ever fails. Figure the factory units fail often enough, it's hard to do worse.
Thanks for keeping us posted. Very interesting to hear that the recharge cured the hiss/squeal.
Unfortunately, replacing the evaporator is a big job. An evaporator leak is high up there on my list of most feared P-car repairs. I have found an outfit that sells aftermarket evaporators at a nice price ($178). Never purchased from them, don't know anyone who has. But, I'm willing to give one a shot, if my evaporator ever fails. Figure the factory units fail often enough, it's hard to do worse.
06-24-2003, 05:04 PM
#21
Pro
Thread Starter
Hi guys,
well, I've let them charge the system about 2 years ago. But I don't know if the leak was there already at that time...
We'll see how long it's gonna keep it's charge this time.
They told me it's not the evaporator which is leaking but the tube attached to the evaporator. This tube is not in a straight line but is curved/twisted. So after some time it's in these curves the material cracks and leaks. So I was wondering if there's any DIY way to repair this leak. Any idea's?
Cya and have a nice day.
well, I've let them charge the system about 2 years ago. But I don't know if the leak was there already at that time...
We'll see how long it's gonna keep it's charge this time.
They told me it's not the evaporator which is leaking but the tube attached to the evaporator. This tube is not in a straight line but is curved/twisted. So after some time it's in these curves the material cracks and leaks. So I was wondering if there's any DIY way to repair this leak. Any idea's?
Cya and have a nice day.
07-01-2015, 10:44 AM
#22
Bumping this up. Appear to be having the same problem.
When AC is off there is no hissing noise.
When I turn the AC on it sounds almost like air escaping through a small hole. It's intermittent and does not change with fan speed or engine RPM. It sounds like its coming from under the center of the dash. There appears to be an AC radiator of sorts in that region. AC blows reasonably cold
Could this be caused by low refrigerant?
When AC is off there is no hissing noise.
When I turn the AC on it sounds almost like air escaping through a small hole. It's intermittent and does not change with fan speed or engine RPM. It sounds like its coming from under the center of the dash. There appears to be an AC radiator of sorts in that region. AC blows reasonably cold
Could this be caused by low refrigerant?
07-04-2015, 08:00 PM
#23
I'd try a regas first to see how much gas is in it. Plus they will vacuum test for any leaks.
The 'radiator' you can see through the flap behind the ashtray is the evaporator and whilst it is a cheap part (got one in the UK for £70 this year) the amount of labour cost to replace it is 10x that figure. I've just had it swapped out in my 964 and previously in a 993 I owned
My advice is try everything else first, new condensor, receiver/dryer, expansion valve etc before you decide on an evaporator but accept like I did you may end up having it all done
Worth it in the end though.
Here's what came out:
and what went in:
The 'radiator' you can see through the flap behind the ashtray is the evaporator and whilst it is a cheap part (got one in the UK for £70 this year) the amount of labour cost to replace it is 10x that figure. I've just had it swapped out in my 964 and previously in a 993 I owned
My advice is try everything else first, new condensor, receiver/dryer, expansion valve etc before you decide on an evaporator but accept like I did you may end up having it all done
Worth it in the end though.Here's what came out:
and what went in:
07-05-2015, 05:02 AM
#25
I thought all cars now run r134a as the previous stuff is now illegal (ozone damage)? That's the case in the UK. There is usually a sticker on the compressor next to the gassing ports telling you what gas to use.
