958

Hello, and this is my first post. I've done quite a bit of lurking and scouring after buying my one-owner 2013 Cayenne S Hybrid, but there suddenly seems like enough new problems - after 2 full years of trouble free driving - that I figured I'd share & hopefully compare notes.

On a long drive home several weeks ago from the mountains in Redding to San Francisco (LOTS of downhill driving), strange things started happening. The car felt sluggish, the cruise control would no longer stay engaged, and I eventually realized that the brake pedal, once depressed, wasn't fully returning to its upright position. I've been avoiding driving it ahead of repairs, and must prop up the pedal with my left foot when doing so to keep it from riding the brakes constantly.

This isn't the typical report of the brake pedal '"falling" all the way to the floor, which is often the sign of a failing master cylinder (?). The brakes actually work fine, but the pedal itself doesn't seem to be returning, doesn't want to spring back & stay all the way up after being depressed, which of course was also triggering the cruise control to disengage. I'll be replacing the brake pads up front shortly, but the brake pad sensors haven't lit up and the rotors are still in great shape.

I've all of a sudden had several problems all pop up at once, though I have not idea if they're related:

-last year the check engine light came on, indy mechanic said it was 'likely' the secondary emissions pump. Haven't gotten to it yet.

-I can't quite figure out if it's related, but I swear - even while propping up the brake pedal with my left foot - the acceleration feels sluggish, so I step on it more, and THEN things 'catch' as the car suddenly finds all of its horses and accelerates.

-water pouring into the footwell; first mainly on the passenger side, then when I banked a right turn on that same big drive home, a tremendous amount came gushing onto my feet while driving. The car is always garaged and it hasn't rained in ages. I don't even run the AC all that often, but I'm guessing it's condensation, or possibly even last year's water??? I've seen enough YouTube videos of people indicating there are drain plugs under each wheel well, and a tube below the passenger side dash that drains condensation, so I'll be checking those.

-Indy mechanic claims it's throwing throwing OBDII codes for emissions pump, brake booster, brake travel sensor (is that actually a thing?) and the brake light switch. I'm not sure I 100% trust this assessment, or am at least questioning the possibility that multiple codes are the by-product of one larger issue (?)

other ongoing issues:

-the panoramic sunroof is VERY squeaky & rickety sounding, always has been. Sounds like I need to install some felt vs. lubricant?

-And my personal favorite: the horn sticks ON! This I know is unrelated, but figured I'd see how many others have had the same issue: a gentle tap leads to a HOOOOOOOOOOOOOOOOOOOOONNNNNNNNNNKKKKKKKKKKK for about 20 seconds, making lots of new friends in the process.

-There is a small oil leak that has developed, apparently where the hybrid motor connects to the engine. Was quoted $2600 to fix. No thanks, i'll just keep feeding my thirsty beast.

The total of these expenses is spectacular, and yet I still LOVE my beloved Cayenne, so I'm going to try to do some of this work myself to mitigate expenses. Also been doing some deep dives on VW parts interchange, which are significant, and will report my findings.

wkearney99

there's some 'frog mouth' drain tubes on the AC condenser box. They're up behind the right front wheel well lining. Cut the end of them off, as gunk tends to get stuck in them and prevents water from draining.

there are drains from the sunroof corners down to under the vehicle. a simple way to clean them us to use some stiff weedwhacker string trimmer filament fed through the holes until it comes out the bottom. DO NOT use high pressure air, otherwise you risk blowing the tube off the fittings and that'll let water drain directly into the passenger compartment.

the rule I've heard about the pano roof is that once it's out of warranty, remove the fuse that powers it. it's VERY expensive to replace.

likewise, water in your floors IS A BAD, BAD THING. There's wiring under there. Get the carpet up and dry that area out. Because if the wiring under there starts corroding from the moisture then you've got a electrical basket case on your hands.

958

Thanks for the heads up & response! Opened up the passenger footwell drain tube and a BUNCH of water gushed out. While I was in there, also noticed that the bottom of the cabin filter was wet. I've had WeatherTech mats in from day 1 but took them out to dry, thanks for the heads up & as it is super hot & dry outside right now it should hopefully dry out in the garage with windows rolled down.

Spent a good amount of time opening up the wheel well, then was super puzzled as to where the drain plugs were. It took me a minute and some confirmation that, at least on the right side, it had already been removed! Contemplating if I should crack open the drivers side as well.

Will check out the sunroof drains, though I wonder if that maybe requires (or is much easier/more accessible) with a lift? I rather like my pano room & don't want to disable, will explore other options. There appears to be an emergency manual closing ability if something goes sideways but will enjoy it for now.

mikegally

Hi,
when I bought my 2012 CD recently i noticed the sunroof did not run smooth at all, felt like the motor / track was under huge stress and I was worried something was gonna go bang any second.
I cleaned the track as best I could with a cloth and a little degreaser, got all the dirt and old grease out as much as possible then applied some 'Mercedes' lubricant specifically for the sunroof.
What a transformation, it now runs so smoothly.
I bought my grease from a seller on ebay uk who obvs buys the bulk tin and splits it into small tins, it arrives in a small container but its enough for 3 or 4 applications, it now sits in my glovebox. Its so cheap (£8) it would be rude not to give it a go. You can also get the genuine VW sunroof grease in a tube for about £30, just search G00045002 in ebay

https://www.ebay.co.uk/itm/Mercedes-...UAAOSwRmNdKlBZ

Des des

Hi, did you find out why the brake pedal was staying down? I have a hybrid, the brake pedal stays down after about 10 mins of driving, park it up for the night then iWork's again the next day then stays down after 10mins of driving?