Bruce In Philly

2009 C2S 50K miles

Car was in rain today and parked nose down on a slight decline. No water inside yet..... started driving and got dripping from the light panel above mirror.

What's up with this. What should i check for... the sun roof or the windshield.

Background: I owned the car just over 1 year and no issues. I had the windshield replaced from a stone last summer. A few days ago I opened the sunroof from the first time since fall. Today after my drippy drive, I opened the sun roof and found water in the leading trough.... not much but there was water in there. The sunroof was closed tightly .... I am 99% sure of it .... well darn sure at least. The sunroof looks aligned perfectly when closed.

So, sunroof? windshield? Is this common and is there a common adjustment?

Peace
Bruce in Philly

beden1

Check the drain holes in the sunroof channel to make sure they are clear and not clogged.

Also check the seal around your windshield since you've had it replaced.

BillB128

If the sunroof drain holes are clear, you could try sealing the sunroof opening with a plastic garbage bag and clear packing tape(making sure the area is clean to avoid scratching). Then you could use a garden hose to spray around the windshield to see if that is where the leak is coming from.

Bruce In Philly

Update:

All drains are open although the front passenger is a little slower. With the roof open, I poured water into the corner areas and watched the outflow. So, I don't really know what the problem is. Maybe given the forward cant of the car and maybe the outflow was as little slower than the inflow, it leaked.

Another test I performed was just pour water over the closed sunroof seams and watched what happened. Well water dissipated pretty darn quickly both on the leading and trailing edges of the roof so this gasket may not be doing its job.

I think I will replace the gasket for about $90.00

Another issue I had was finding the darn drain holes. I snapped this bad 'droid photo of the leading passenger side drain hole with a weed wacker cord jammed in there. I hope this helps anyone looking for the hole. You can see the hole if you look really hard with a bright light. I fed about 3 feet of cord in there until it hit something and stopped. Did I hit a clog? I dunno.

The other thing to do is pull the inside wheel liner out and blow/suck water through with a shop vac but I am not that motivated.

Anyone change one of these gaskets? I think the part is 997 564 211 00

Peace
Bruce in Philly

caslca

Hey Bruce,
Did you ever figure out how to DIY replace the felt gasket?

Bruce In Philly

I never did the job.... the drip just stopped and I don't know why. These cars be weird sometime.

Maybe the angle of car has to be just so.... with just the right amount of rain.... I did run that weed wacker line through the drain holes but I really suspect the windshield as I had it replaced.... the trim around the glass was a sloppy job but even then, the glue should have sealed it. I really don't know.

BTW, I discovered later when I removed a wheel liner, that the stop I hit with the weed line was an "L" in the line where it drains into the top of the wheel well. If you want to run a line 100% through, you will have to start from the top of the wheel well. It is a stupid design as the water just runs free inside of the well and soaks a piece of electronics that appear, to me, to be the TPMS readers. Dopey design.

Peace,
Bruce in Philly

nwGTS

Bruce, no TPMS reader in wheel well on 997.2. Only one big one in the middle of car.

Felt liner replacement is a big job. Have to remove entire sunroof mechanism. Mine came off on the rear side. Dealer thought it would be easy to just push back into place but found it required special tools, complete disassembly and two weeks with the car.

Bruce In Philly

YIKES! Thanx for the data.

I wonder what that piece of electronics I see. It is near the bottom, at the rocker. I should have snapped a pic or wrote down the part number. I could not find it in the PET diagrams. Really odd.


Peace
Bruce in Philly

nwGTS

More BS from me. Sorry.
I went and looked myself. Sure looked like an antenna.
Looked in my 997.2 supplemental docs and found that there are BOTH wheel well antennae AND a central antenna that then sends the info to a forward battle station:

Design and function
Control unit
As on previous models, the control unit is located at the front of the luggage compartment on the right-hand side. The control unit analyses the incoming data from the antenna and forwards the relevant information to the instrument cluster. Since the data is transmitted via cable from the central antenna, the control unit is designed to pick up both frequencies (433/315 MHz). If a new control unit is installed, it must be coded accordingly.
Triggers (trigger senders) The four triggers, which are located under the wheel housing liners in each of the four wheel housings, send a 125 kHz signal directly to the wheel electronics units in order to transmit the desired information to a central antenna immediately.
When the vehicle is unlocked, the control unit initiates the first 125 kHz signal for each trigger in the four wheel housings one after the other, starting at the left front in clockwise direction. Then, the wheel electronics units are only triggered approx. every 60 seconds while the vehicle is moving. Since the range of the trigger signals is limited to the relevant wheel housing, any possibility of cross-talk affecting other wheels is almost totally eliminated. Depending on many and varied influences from the immediate environment, such as reflections (wet roads, metallic floors, guide rails, etc.), external interference (external transmitters), as well as bad positioning of the wheel electronics units with respect to the trigger and/or central antenna, a trigger signal can fail to reach the related wheel sensor or the feedback data protocol can get lost on its way to the central antenna. The control unit responds immediately by re-triggering the trigger – repeatedly if necessary – at the wheel position at which the expected protocol has failed to materialise as soon as the initiated trigger cycle from front left to rear right is completed. This concept reduces system interference and the wheel electronics units are detected much faster
Central antenna
The digital central antenna (reception frequency 315 or 433 MHz) is secured to the vehicle floor in the center tunnel between the water tubes. The signals received from the wheel electronics units are digitalized in the antenna and forwarded to the control unit via two lines (LIN bus). The digital antenna has an integrated self-diagnosis facility. This means that when a fault is detected, it is stored in the control unit fault memory and displayed on the PIWIS Tester.
Wheel electronics
The wheel electronics unit (wheel transmitter, 433 or 315 MHz) is screwed to the rim using the wheel valve. The wheel electronics unit comprises the following components: Pressure sensor, temperature sensor, roll switch, measuring and control electronics, receiver and transmitter as well as a battery.
The wheel electronics unit can be triggered and receives send requests from the TPM control unit via four trigger senders. This means that the antenna always receives only one data protocol and this comes from the wheel electronics unit that received the request to send. This gives the system added protection against crosstalk affecting other antennas. Higher transmission power is used due to the longer radio link to the central antenna. The roll switch detects whether the wheel is stationary or turning. This information is used either to start a triggered learning process for a moving wheel or to switch off the wheel electronics unit when the wheel has been stationary for a long time.
To avoid confusion with 1st generation wheel electronics, the new wheel electronics unit can be identified by the modified shape of the housing, the small air filter and the part number stamped on it. A modified data protocol ensures that the wheel electronics unit will not be detected if installed incorrectly and this is stored as a fault in the fault memory.

Bruce In Philly

That is just too darn complex. Does it really have to be that way for a TPMS system?

Peace
Bruce in Philly

mikes70

Bruce, on the windshield......spray soapy water around the top and sides of the exterior of the shield, then take compressed air from the inside and blow around the perimeter. I did auto glass for 15 years (still in the glass biz) and this is how we would trouble shoot leaks.....mike

slicky rick

Now that's an idea! Thanks for sharing