Sooner or later you are going to have to replace the blower motor that is located in the right side of the engine compartment. One day you will start the car and think that have a cat caught in your fan because of the noise.
Dont despair, this is an easier (and cheaper!) fix than you might think at first. Porsche has discontinued the original blower motor for the 964s and they have replaced it with the 993 version (993-624-328-01). This is the exact same fan and for the $415 you pay Pelican Parts for it you get the complete assembly motor, housing everything ready to pop in and drive away.
Well ALMOST !
There is one small problem. The 993 assembly is just a little bit different The bushings that the mounting bolts go through to mount to the intake manifold are a little longer than the 964 ones. It will go together (barely with force) and look OK (if you can live with a 1/2 gap at the fan housing), but it is so much easier to do this right.
This is a diagram of the blower motor assembly. There are two bolts located on the right side of the unit one in front and the other you will have to feel around a little to find under the fan. Remove the bolts and disconnect the wiring leads to the blower and the resistor. You will also need to disconnect the hoses to the distributor and rear light vents then loosen the band clamps at the top and bottom of the tube that the resistor is mounted in.
You will have to take the screws out of the housing to get to the bushings to swap them out. Just remove all of the screws around the outside edge and the motor section can be pulled away. After you do this to the old unit (in case you screw anything up you do it to the old unit !) Do the same to the new unit
The difference between the bushings doesnt seem to be that critical, but it will cause you major headaches later when you try to install the assembly. The longer bushings hold the entire assembly away from the mounting pads (located on the intake manifold). You cannot get more than 1 turn of the bolts into the pads and you can EASILY strip out the mounting pads.
I could not figure out what was wrong when I did this because everything SEEMED to be together except the bolts did not go in as far as they were and the duct going to the engine fan housing was off just a little. The next day, I checked to see that everything was still OK and I found the front bolt had come out and the unit was not connected to the engine fan housing (see circled areas).
I took everything back apart and realized the only difference was the bushings and when I tried to bolt them to the mounting pads, I could only get a single turn of the threads to engage obviously not enough. I tried the old bushings and everything went together just like it was before.
It is a statement about the precision of these cars that a small difference in the bushings keeps all of the other parts from lining up correctly OR you could say it is a sign that Porsche should do their homework on replacements a little better. They must have been sidetracked by the SUV !