sandman

While driving with the A/c switched on, I noticed a sqealing noise coming from somewhere in the car. The sqealing increased with the speed of the A/c blower. On 1 I could not hear it but as I increased to 2 and then to 3 it got louder. It seemed to be coming from the a/c vents. However, when I got home I turned off the car and was in the garage for a while. The cooling fan went on as normal and I noticed the squealing. It was coming from the fan.

Has anyone experienced this?? Where is the fan located and what is the connection to the A/c blower??? How can I get it to stop sqealing???

Any help will be appreciated.

Thanks

Sandman

GT9111

This happened to my car once before. Locate the A/C fan and add some lubricant to the bearings which will most likely eliminate the noise.

sandman

Where is the A/c fan. I assume it is in the engine bay as the noise is coming from there. Could you please provide a few more details.

Thanks

Sandman

Jack Ennuste

Loose and slipping belt might be another possible cause.

Randall G.

Hey Sandman,

>The sqealing increased with the speed of the A/c blower. On 1 I could not hear it but as I increased to 2 and then to 3 it got louder. It seemed to be coming from the a/c vents.

This sounds like 1 of the 2 interior fans, located in the trunk, left and right side. These fans are controlled by the **** on your climate control unit (speeds 1 through 4). It's common for these fans to squeak as they age, with the squeak being proportional to fan speed. A common problem on the 964 board, I suspect it will start showing up more often on 993s as they age.

>However, when I got home I turned off the car and was in the garage for a while. The cooling fan went on as normal and I noticed the squealing. It was coming from the fan.

Now, this sounds like the rear blower--the interior fans don't run when the ignition is off. Of course, the rear blower is in the engine compartment, upper-left side. But, the rear blower only runs to supply heat or cool the engine. When in heating mode, the rear blower will shift from slow to fast-speed when the interior fan speed is higher than 2. But, you said you were running the A/C, so the interior fan control should have no impact on rear-blower speed. Unless perhaps you happened to have the A/C on, but the temperature set high. In which case, there would still be a demand for heated air.

There's also the A/C condenser fan, located in the left-front fender, in front of the tire. It normally runs in slow-speed, but will shift into fast-speed if system pressure (load) gets high enough. But, again, this fan doesn't run with the ignition off.

In summary, I'm not sure what to make of your problem just now. <img border="0" title="" alt="[Wink]" src="wink.gif" />

Didn't you have a problem with your evaporator awhile back? How did the repair work out?

sandman

Hi Randall

Thanks for the detailed input. It seems that both fans are sqealing. The ac/ blower and also the cooler fan in the Engine compartment. Any ideas on how to get rid of the sqealing???

My evaporator work was completed last December. I had to replace it with a new one. Here the weather is always warm so my A/c is in constant use. A/c works fine now.

Thanks again

Sandman

Randall G.

Hey Sandman,

For your new evaporator, did you wind up buying a Porsche unit, or the low-cost aftermarket evaporator?

If your rear blower is squeaking, I personally wouldn't bother trying to lube it. As you probably know, these fans wear out often, and will eventually seize, causing the fuse to blow. The fuse blowing leads to other HVAC problems, such as an inoperable defroster.

If your front blowers (left and right, in the trunk) are squeaking, it may be possible to stretch their life out awhile longer by using a syringe to lube the bearing. Some 964 owners have had luck with this approach.

I can send you links for a few threads describing replacement of the left and right front blowers on a 964 (I imagine a 993 is very similar). The left blower is extra tricky, due to the A/C line running above the blower housing. But, someone just posted recently that the blower can be replaced by just loosening the line, without having to break it open. Of course, if you have to break open the line, you'll need to take the car to an A/C specialist for gas collection and recharge.

I've never heard of anyone with a squeaking A/C condenser fan (left-front fender, forward of the wheel). Suppose you can try lubing the motor bearing on it, as well. Or, replace it. It's about $100. Replacing the condenser would--again--require an A/C specialist for gas collection and recharge.

Best of luck!

Flying Finn

Randall,

How about posting the links here?

I just had one squel not long ago and lubing the fans (in trunk) solved the problem but for future I wouldn't mind knowing how to change them.

Not to sound lazy (I could go & search of course) but I though perhaps posting the links here would benefit others as well.

Thanks!

Randall G.

No problem, FF. I'll post the links when I get home tonight. I have them saved in a special folder on my home e-mail.

Randall G.

One more thought, Sandman. The squeak you're hearing isn't coming from the small fan that's used for the interior temperature sensor, attached to the CCU, is it? This tiny fan can run for something like 20 minutes after the ignition is shut off. If you put your head up close to the grill for the temperature sensor, you should hear it running.

Flying Finn

Thanks!

Randall G.

Hey FF,

Here are the links. On one link, the A/C lines had to be broken open to access the left blower. On another link, someone was able to remove the left blower without breaking open the A/C lines.

Also, section 85 of the 993 shop manual has detail on removing the blowers. It doesn't mention having to break open the A/C lines like the 964 manual does, so 993 owners may have gotten lucky here.

<a href="http://forums.rennlist.com/cgi-bin/rennforums/ultimatebb.cgi?ubb=get_topic;f=4;t=002741" target="_blank">Interior Fan Replacement Tips #1</a>

<a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic;f=4;t=004349" target="_blank">Tips #2 - Left Blower Removed Without Cracking A/C Line</a>

<a href="http://forums.rennlist.com/cgi-bin/rennforums/ultimatebb.cgi?ubb=get_topic&f=4&t=002968" target="_blank">Tips #3 A/C Line Broken to Replace Left Blower</a>

Finally, there is a wonderful DIY on troubleshooting the HVAC system servo motors on John Miles' 964 page:

<a href="http://www.porsche964.co.uk/technical/servos.htm" target="_blank">HVAC Servo Motor DIY</a>

One major difference between the 964 and 993. For the 993, the temperature mixing chamber servo motors are inside the cabin, in the driver/passenger footwells. On the 964, all 5 servo motors are under the flimsy black cover at the base of the windshield.

sandman

Thanks Randall

I replaced the Evaporator with the Porsche unit. I got a decent price on it from FVD in Germany. Since the a/c is used 90% of the time, I decided against the aftermarket evaporator.

The sqeal is definately coming from the rear blower. You mentioned that it was not a good idea to lube it. Any ideas of the cost of a new one??

Thanks

Sandman

Flying Finn

Thank you Randall!

Randall G.

My pleasure, FF.

Sandman .... I recommended against lubing the fan because they have a long history of failures, with the failures leading to seized fans, blown fuses, and induced HVAC bugs.

Pelican Parts (for example) carries the rear blower, but at a price of $259. They used to have it for the (relatively) wonderful price of $99 (or was it $119?).

<a href="http://www.pelicanparts.com/catalog/shopcart/911L/POR_911L_exhaus_pg1.htm" target="_blank">Pelican Parts Rear Blower</a>

Pelican Parts also has an excellent DIY for installing the rear blower, albeit for a 964. The 993 installation is simpler, as you don't have to worry about the bushing exchange that is discussed. Also, if you have a mid-year '95 or newer 993, the ducting surrounding your rear blower will look different.

<a href="http://www.pelicanparts.com/techarticles/964_blower_motor/964_blower_motor.htm" target="_blank">Rear Blower DIY for 964</a>

Best of luck, and let us know how it goes.