03 Explorer - Cooing noise from AC/Heater unit upon accelerating

Hi Everyone,

I am coming up on my 100,000 mile extended warrenty limit and I am
starting to experience some trouble with my AC/Heating unit. I get a
"cooing" noise, like a dove or pidgeon, when I accelarate. It is not
all the time but can happen when accelerating from a stop or from 60
MPH to 65 MPH. It seems the hotter the weather the more pronounced and
often it occurs. We actually had a cool enough day that I put on the
heat and the same thing occured.

I took the truck by the Ford dealer about a month ago complaining about
the temp output of the AC. The output is cool at first but 2:00
minutes into a ride it is actaully hot to the point that in 85 degree
weather it is better to open the window. The service rep and a
technician used a thermometer and said as long as the reading is 40
degrees or less within 30 seconds of turning on the AC it was within
tolerance. Unfortunately I ran the AC on the way over to the shop in
order to deplete any cold air that had gathered in the system overnight
- it was 7:00am when I went to the shop and I believe that there was a
reserve in the system (cold air) when they tested the system. I was
told to wait until an 85 degree day came along and then go back and
have it tested. I work during the week and every weekend so far has
been damp and rainy. It is also a $124 diagnostic charge to test the
system for leaks, and they already say it is within tolerance. I was
told that AC system cooland doesnt' "go bad" and that any time a
recharge is necessary it is because there is a system leak. Is this
true?

I just now started to develop a noise in the rear axle area that occurs
when breaking/turning. It doesn't matter which direction I'm turning
so I believe it is activiated when I brake. This is more easily
re-created so I'm sure they'll figure this out.

I have made an appointment for Thursday this week and was hoping somone
may have some insight into this issue. I just know Thursday will be
cool and not be able to reproduce the poor cooling and I'm not
confident that the dealer will be able to reproduce the cooing sound
either. Unfortunately I can't stick around to test drive the truck for
them.

Anyone ever experience the cooing sound?

Dave K.

Our '02 eddie bauer with dual auto temp control makes a vacuum leak hiss
sound in cold weather when you press the accelerater and hold the pedal down
for a few seconds (light acceleration) after the car is parked outside over
night (under 20 degrees). It sounds like it's comming from the ac/heater
control head below the radio. It will also make a slightly different sound
when it's been parked out in the hot sun of summertime under light steady
acceleration. I'm guessing there's a vacuum leak in the control head, thats
affected by tempeture thats warping the control head to cause a vacuum leak.
The sound will change/go away the moment you let up or press down harder on
the gas pedal.
wth

"dekern" > wrote in message
ups.com...
> Hi Everyone,
>
> I am coming up on my 100,000 mile extended warrenty limit and I am
> starting to experience some trouble with my AC/Heating unit. I get a
> "cooing" noise, like a dove or pidgeon, when I accelarate. It is not
> all the time but can happen when accelerating from a stop or from 60
> MPH to 65 MPH. It seems the hotter the weather the more pronounced and
> often it occurs. We actually had a cool enough day that I put on the
> heat and the same thing occured.
>
> I took the truck by the Ford dealer about a month ago complaining about
> the temp output of the AC. The output is cool at first but 2:00
> minutes into a ride it is actaully hot to the point that in 85 degree
> weather it is better to open the window. The service rep and a
> technician used a thermometer and said as long as the reading is 40
> degrees or less within 30 seconds of turning on the AC it was within
> tolerance. Unfortunately I ran the AC on the way over to the shop in
> order to deplete any cold air that had gathered in the system overnight
> - it was 7:00am when I went to the shop and I believe that there was a
> reserve in the system (cold air) when they tested the system. I was
> told to wait until an 85 degree day came along and then go back and
> have it tested. I work during the week and every weekend so far has
> been damp and rainy. It is also a $124 diagnostic charge to test the
> system for leaks, and they already say it is within tolerance. I was
> told that AC system cooland doesnt' "go bad" and that any time a
> recharge is necessary it is because there is a system leak. Is this
> true?
>
> I just now started to develop a noise in the rear axle area that occurs
> when breaking/turning. It doesn't matter which direction I'm turning
> so I believe it is activiated when I brake. This is more easily
> re-created so I'm sure they'll figure this out.
>
> I have made an appointment for Thursday this week and was hoping somone
> may have some insight into this issue. I just know Thursday will be
> cool and not be able to reproduce the poor cooling and I'm not
> confident that the dealer will be able to reproduce the cooing sound
> either. Unfortunately I can't stick around to test drive the truck for
> them.
>
> Anyone ever experience the cooing sound?
>
> Dave K.
>

There is more to the "spec" then whether it's reading 40 degrees
within 30 seconds. A system that is low on freon can sometimes do
that and then after a while the evaporator gets too cold and forms
ice, blocking teh airflow and not cooling very well. It's also
possible that the cooing sound is a vacuum leak and that at idle
there's enough vacuum to keep all the flapper doors where they should
be but when you are driving it they may not be staying in position.
Usually that will affect airflow. So if you have no change in airflow
it's probably not either of those. If you have automatic temp control
it's possible that has gone bad and it is causing your problems. The
freon doesn't go bad but compressors do. It's possible your
compressor is on it's way out and when that happens it sometimes fills
the system with a very fine black sludge that can clog some of the
passages. When they "tested" your system did they do anything other
then measure the air coming out of the ducts?

I'd have the rear axle checked pronto if it's making noise. They can
be very expensive to repair.

Is your extended warranty a FORD warranty or some other company? Do
you have to take it to a Ford Dealer? If you don't have to go to a
ford dealer just take it someplace that's convenient to you and have
them take a look at it and possibly fix it under the warranty if you
don't need to go to a Ford dealer.


On 23 Jul 2006 17:39:17 -0700, "dekern" > wrote:

>Hi Everyone,
>
>I am coming up on my 100,000 mile extended warrenty limit and I am
>starting to experience some trouble with my AC/Heating unit. I get a
>"cooing" noise, like a dove or pidgeon, when I accelarate. It is not
>all the time but can happen when accelerating from a stop or from 60
>MPH to 65 MPH. It seems the hotter the weather the more pronounced and
>often it occurs. We actually had a cool enough day that I put on the
>heat and the same thing occured.
>
>I took the truck by the Ford dealer about a month ago complaining about
>the temp output of the AC. The output is cool at first but 2:00
>minutes into a ride it is actaully hot to the point that in 85 degree
>weather it is better to open the window. The service rep and a
>technician used a thermometer and said as long as the reading is 40
>degrees or less within 30 seconds of turning on the AC it was within
>tolerance. Unfortunately I ran the AC on the way over to the shop in
>order to deplete any cold air that had gathered in the system overnight
>- it was 7:00am when I went to the shop and I believe that there was a
>reserve in the system (cold air) when they tested the system. I was
>told to wait until an 85 degree day came along and then go back and
>have it tested. I work during the week and every weekend so far has
>been damp and rainy. It is also a $124 diagnostic charge to test the
>system for leaks, and they already say it is within tolerance. I was
>told that AC system cooland doesnt' "go bad" and that any time a
>recharge is necessary it is because there is a system leak. Is this
>true?
>
>I just now started to develop a noise in the rear axle area that occurs
>when breaking/turning. It doesn't matter which direction I'm turning
>so I believe it is activiated when I brake. This is more easily
>re-created so I'm sure they'll figure this out.
>
>I have made an appointment for Thursday this week and was hoping somone
>may have some insight into this issue. I just know Thursday will be
>cool and not be able to reproduce the poor cooling and I'm not
>confident that the dealer will be able to reproduce the cooing sound
>either. Unfortunately I can't stick around to test drive the truck for
>them.
>
>Anyone ever experience the cooing sound?
>
>Dave K.