Cowl Drain Clean Out
 

While the wife is in the field teaching the little ones about nature, nature leaves lots of presents. Leaves and debris.

This is something you want to consider because clogged cowl drains will raise the water level to a point that water can enter the cabin and make its way to things that are electrical (boxes and wiring).

The 958 cowl drain access is different than previous models. Using my preferred maintenance method , I plan on doing this at least once a year, if not more.

There are two maintenance methods:
1. Partial release of the wheel liner mounting screws and nut (My preferred)
2. Full release of the wheel liner from its screws, two nuts, and complete removal of the liner.

Jack/Lift points are in the owner's manual and at http://www.porscheownersmanuals.com/...-with-the-jack. My floor jack has a large rubber disc so I did not use a alternate puck.

Tools:
1. Jack, Jack stand or equivalent, and wheel removal and fitment tools
2. 10mm socket
3. T25 bit
4. Favorite socket wrench or hand electric drive (my preferred)
5. flat head screw driver
6. Garden hose (NO PRESSURE WASHER)

Pictures speak to the procedure. Good luck!

Top notch post. Thank you.

Does anyone know if this is the same on a 958.2/2015+?

Agree, very thorough post.

Can these drains be deleted? I don't see how they would keep water out when fording a stream.

The ac drains are lower if i recall. The cowl drains are much higher. Some recommend not reinstalling the rubber piece pictured but since there is an opening in the wheel well to the engine compartment no sense inviting heat and engine compartment smells into the cabin and electrics in the cowls. JMHO.

Thanks CAVU. Will have to try it this weekend. How you are supposed to do a good job cleaning under the cowls with all the stuff they crammed in there is beyond me :banghead:

Mine spends almost no time under trees and when I pulled the cowl covers both sides are packed full of debris :eek:

So PSA to all those (like me) that think theirs are going to be clean as it doesn't see many trees: pull the cowl covers and look, you too might be shocked!

Really nice description. Is there any way to do this with pressurized air, say once a month, to avoid the build up (recognizing that you probably need to do the thorough cleanout first)?

Is there a jacking puck that we should be using with our floor jacks & jack stands for the 958 Cayenne?

You will be amazed with just a simple Hockey puck.

Good question. I updated the DIY with this link which is also in the owner's manual. http://www.porscheownersmanuals.com/...-with-the-jack

Since my floor jack has a larger rubber lift point I did not add additional protection.

As to a jack stand. Safety first. I used my drive on ramp platform and placed it under the lower control arm. No issues.

Based upon my experience I would not use compressed air to clean the cowl out. However, I might be inclined to use it to loosen things up a bit followed by the water to push things out.

Today using this post I tackled the cowl drain clean out. I chose to remove the rear of the fender liner and was able to turn the wheel in to get to the required rear fasteners of the liner. The drains were pretty clear but I chose to remove both of the cowl drains and snipped off the AC condensate drain flapper valve. UPDATE: To get to AC condensate drain I had to drop the plastic under tray.

Left to right are the driver's cowl drain, AC condensate flapper and passenger's cowl drain:

https://cimg6.ibsrv.net/gimg/rennlis...1d74beb616.jpg

Thank you!

Getting added to the 958 DIY forum.. thanks much for the very informative write up of something almost everyone who owns a Cayenne will have to face sooner or later.

Ac drain clogged
 

Hi welcome to the forums!

The AC drain line is easiest to get to from the interior of the vehicle. You need to drop the panel below the dash above the passenger's footwell (1 T15 screw, and then pull it down, disconnect wires and move out of the way).. then look for the rubber hose going through the firewall from the bottom of the HVAC housing. There is a bitch-clamp on the part connecting to the HVAC box.. you have to wiggle it down the hose so the hose can be pulled off the box. A pair of channel locks works well for that. There are specific tools for removing these bitch-clamps (called that because of the "Son'of'a'Bitch" you're going to yell trying to work with them) - local NAPA dealer probably has them, or Amazon for sure.

Anyway - work the hose down off the plastic fitting on the box - then you can take a long screwdriver and poke it through, hopefully dislodging anything plugging it up. On mine, I pulled the entire rubber piece out of the dash and cleaned it out. Some people cut off the rubber flapper on the end (supposed to keep insects out I think..) I haven't - yet.

Some details with a photo or two: https://rennlist.com/forums/cayenne-...-on-floor.html

While you're in the area, might as well change the HVAC filter. That doesn't even require a screwdriver. There are writeups on it here and on Pelican on-line.