99 E39 AC Problem

Hi,

1999 528i here.

Two weeks ago the AC compressor took a dump.

Had my local mechanic replace the compressor, drier and valve.

Now the AC works but not very well.

Took it back and he verified the freon level was good. He tested for
leaks and could not find any.

Before the original compressor went bad, I could keep the temp at 68 and
worked great. Froze me out.

Now, I have to turn it down to like 64 to get any decent cold air coming
through. But it's struggling to cool, and certainly not 64!

In addition, the AUTO function is not working. Using manual settings I
can turn the fans up pretty high. But as soon I select Auto the fans go
to a really low setting and never move from there. Even on the manual
setting the fans don't seem as strong as it used to be.

Do you think this is the final stage resistor?

One other thing, I think the fan clutch might be on it's way out. It's
working but starting to sound like an air-raid siren in the background.

Any suggestions appreciated!

Are you sure it was not a sensor problem all along?

"Yea Right" > wrote in message
...
> Hi,
>
> 1999 528i here.
>
> Two weeks ago the AC compressor took a dump.
>
> Had my local mechanic replace the compressor, drier and valve.
>
> Now the AC works but not very well.
>
> Took it back and he verified the freon level was good. He tested for
> leaks and could not find any.
>
> Before the original compressor went bad, I could keep the temp at 68 and
> worked great. Froze me out.
>
> Now, I have to turn it down to like 64 to get any decent cold air coming
> through. But it's struggling to cool, and certainly not 64!
>
> In addition, the AUTO function is not working. Using manual settings I
> can turn the fans up pretty high. But as soon I select Auto the fans go
> to a really low setting and never move from there. Even on the manual
> setting the fans don't seem as strong as it used to be.
>
> Do you think this is the final stage resistor?
>
> One other thing, I think the fan clutch might be on it's way out. It's
> working but starting to sound like an air-raid siren in the background.
>
> Any suggestions appreciated!
>
>
>
>
>

Yea Right > wrote:
>
>1999 528i here.
>
>Two weeks ago the AC compressor took a dump.
>
>Had my local mechanic replace the compressor, drier and valve.
>
>Now the AC works but not very well.

New compressor or rebuilt? Did he install the specified Freon or one of the
new replacements?

>Took it back and he verified the freon level was good. He tested for
>leaks and could not find any.

What pressures did he see on high and low eides? The pressures tell you more
than the level.

>Before the original compressor went bad, I could keep the temp at 68 and
>worked great. Froze me out.
>
>Now, I have to turn it down to like 64 to get any decent cold air coming
>through. But it's struggling to cool, and certainly not 64!

Doesn't matter how low you turn it, either the compressor is on or it is off.
Once you turn it down low enough to turn the compressor on, it is on.

>In addition, the AUTO function is not working. Using manual settings I
>can turn the fans up pretty high. But as soon I select Auto the fans go
>to a really low setting and never move from there. Even on the manual
>setting the fans don't seem as strong as it used to be.
>
>Do you think this is the final stage resistor?

It's not the usual failure.

>One other thing, I think the fan clutch might be on it's way out. It's
>working but starting to sound like an air-raid siren in the background.

Fan clutch where? Do you mean the internal AC fan? It has no clutch. If
it is squealing, put some light oil on the bearing and see if it frees up.
Ultimately the solution is replacement but it's a pain.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

(Scott Dorsey) wrote in
:

> Yea Right > wrote:
>>
>>1999 528i here.
>>
>>Two weeks ago the AC compressor took a dump.
>>
>>Had my local mechanic replace the compressor, drier and valve.
>>
>>Now the AC works but not very well.
>
> New compressor or rebuilt? Did he install the specified Freon or one
> of the new replacements?

New Compressor, from eBay (I know.....)
>
>>Took it back and he verified the freon level was good. He tested for
>>leaks and could not find any.
>
> What pressures did he see on high and low eides? The pressures tell
> you more than the level.
Don't know
>
>>Before the original compressor went bad, I could keep the temp at 68
>>and worked great. Froze me out.
>>
>>Now, I have to turn it down to like 64 to get any decent cold air
>>coming through. But it's struggling to cool, and certainly not 64!
>
> Doesn't matter how low you turn it, either the compressor is on or it
> is off. Once you turn it down low enough to turn the compressor on, it
> is on.
The compressor goes on when I turn it on, but cold air won't come out
until I turn it down to around 65
>
>>In addition, the AUTO function is not working. Using manual settings I
>>can turn the fans up pretty high. But as soon I select Auto the fans
>>go to a really low setting and never move from there. Even on the
>>manual setting the fans don't seem as strong as it used to be.
>>
>>Do you think this is the final stage resistor?
>
> It's not the usual failure.
>
>>One other thing, I think the fan clutch might be on it's way out. It's
>>working but starting to sound like an air-raid siren in the
>>background.
>
> Fan clutch where? Do you mean the internal AC fan? It has no clutch.
> If it is squealing, put some light oil on the bearing and see if it
> frees up. Ultimately the solution is replacement but it's a pain.
> --scott

Not the AC fan, the main fan in the front of the car. Comes on and off
when AC is on.
>
>

Yea Right > wrote:
>>
>>>Took it back and he verified the freon level was good. He tested for
>>>leaks and could not find any.
>>
>> What pressures did he see on high and low eides? The pressures tell
>> you more than the level.
>
>Don't know

Okay, find that out before anything else.

>>>One other thing, I think the fan clutch might be on it's way out. It's
>>>working but starting to sound like an air-raid siren in the
>>>background.
>>
>> Fan clutch where? Do you mean the internal AC fan? It has no clutch.
>> If it is squealing, put some light oil on the bearing and see if it
>> frees up. Ultimately the solution is replacement but it's a pain.
>
>Not the AC fan, the main fan in the front of the car. Comes on and off
>when AC is on.

There is no connection between the fan and the AC... so if you are hearing
a squealing with the AC on, it's either the compressor or the belt driving
it. That needs to be fixed.

You have a viscoelastic clutch; I can see how it could possibly make
sounds if it was damaged but the normal failure mode is just for it to
slip and the fan to stop turning silently.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

(Scott Dorsey) wrote:

>New compressor or rebuilt? Did he install the specified Freon or one of the
>new replacements?

What do you mean? R12 hasn't been used in cars since 1994.