alien2108

This things fail and are annoying as hell. Clicking sound on right side under the dash. I can eliminate it if I switch on air-recirculation.

I did switch it off again and then manually “persuaded” the stupid servo into final position. Clicking stopped. But I must not click recirculating button again.

99657391500 Part is located in really stupid tight position and it was PITA to even have a look.

Did anyone actually replace it? What does fail inside the servo?

Thnx,
Alen

alien2108

Btw this part seems identical to common VW/Audi… part 1J1907511A! Under $20 on Aliexpress. I ordered one and will try to replace it!

alien2108

I performed the neurosurgery. It is quite a pain since it is in tight space but patience

You must first put it into the recirculation mode, so the new part will properly slide back in for the flap/shutter. But if it doesn't do not worry, someone should press the recirculation button and you will slide it in once the correct position occurs.

You first remove the screw, then you disconnect the cable, pull it out a bit so the plug that rotates the flap/shutter comes out and then there is another lever above that you have to disconnect (not seen on the pic, see below)!




Now the analysis of the part failure and how to save almost 300EUR

Porsche Part No: 99657391500 = 300EUR

But it is INDEED HELLA/VALEO 1J1907511A as you can see both numbers on the original part. This costs 30-50EUR as a part number for VW/AUDI/SKODA/....BUT on Aliexpress you can buy it for under 20EUR.

It is nothing else but a couple of plastic gears and a simple motor. 300EUR!? Come on Porsche....

Original part pic:



Original part above, Aliexpress part below (you can see they actually do it as OEM for some car manufacturer since names are scratched off). I also marked the part that I moved from old to new part (that is the lever you have to additionally disconnect when removing):




The failure occurred due to contacts reporting position bending in wrong direction and cracks in the main gear, thus the gear started skipping and this is the clicking noise you hear under the dash on the passenger side:





So after approx. 1 hour of Car Yoga (I recommend you put the passanger seat all the way back and lower the back, so you can put your legs there) you will have a silent AC again and save yourself 280EUR!

alien2108

Original Porsche manual, where you can see the lever you have to disconnect additionally:

damage98MO

You sir, are awesome. Please accept these 500 good karma points from the community!

theprf

I have changed a bunch of these on VW's which use the same airbox. It's always the white gear that cracks.
The reason, on the VW's at least is the damper binds up and gets hard to move. This makes the gear crack. I usually remove the entire air box to dismantle it, fix the black foam problem, and sand down the pivots for the fresh air damper. I also leave the screws holding the servo motor a little loose so that when it does bind up there is a way to limit the force on the white gear.

alien2108

I do not think you could get out the whole box without removing the Dash on 996, since that would be the best way to do it indeed.

mrhill

I am trying this procedure right now, I got off the screw and connector. But I just can't disconnect the additional lever,
the part that is referred to as "pivot pin" in the Porsche manual. I cannot get any leverage with a screwdriver in the
tight space.

How did you disconnect this part?

mrhill

Some updates: I finally succeeded to get it out with a very long (30cm) screwdriver using it as a lever against the air con box. See attached picture where I pushed on the black plastic arm. Luckily nothing broke off, I hope to get it back in later.

But get this - on my RHD 996 the motor is inverted! Anybody knows the part number (preferably cheaper Audi/VW part) of the RHD version?

mrhill

Update 2: Everything is working again.

I ended up transferring the broken gear from the new part into the old motor. The original Porsche part seemed of higher quality, too, and I didn't want to lose that. E.g. one of the gears is from metal.

One additional hint - when putting the part back in, make sure the recirculation flap is in closed (recirculation position). With the motor removed, it can be moved by hand from the frunk; it is under the air filter. Mine had moved during disassembly, and at first did not work correctly. I had to remove and re-assemle again.

I am still not sure if there is any difference between the LHD and RHD part - visually they look identical, but it does rotate into the opposite direction. Maybe the difference is in the wiring to the connector.