New (to me) Cayenne with some issues

[Marcone]

Hi all.

New to the forum, on the Cayenne end of things anyways, owned a few 80's and 90's turbos before, now its family time, bought a 2004 Cayenne S for my new family (having my first baby soon)

Well.. Got a great deal... spending a lot to chase some dragons.

So, I dont really know these cars in specific, but i know cars enough to not be too scared to get a used one. This particular car had no history, test drove it and it was great. Only major issue i could see was the factory nav deck wouldnt turn on, Low range mode selector/diff lock switch wasnt lit up or working and there were some noises like servos in the dash. Easy fix i thought from what i read.

Anyways. Now i've had it for a week and i've decided to bring maintenance up to check, so i had the oil changed, put spark plugs (ngk iridium), coils(beru), air filters, cabin filter and bought O2 sensors and a transmission filter / gasket kit to get that done soon.

So, problems i've noticed which prompted a bunch of the maintenance was :

1) Bad gas mileage, like bad bad... Dash says i can get down to 11.4 l/100km but my wallet says different. Half tank of premium and im at 250 km...

(i have a sneaky feeling that since i looked into the reason why the diff lock selector wasnt working i messed something up. Selector switch was disconnected by the previous owner. Possibly there is a fault in the system and is now engaging something that is killing my gas mileage, even tho there are no lights telling me its on or in any mode, I do hear something in rear engaging after starting the car.)

2) Key fob doesnt work all the time. Always locks but the red blinking lights dont stay blinking for very long and then when i get back to the car to unlock, the key button keeps re locking the car. After a ton of tries, unlocks. Sometimes the clock is reset as well after going into a store. Back gate button doesnt work and neither do the kessy buttons on the doors. Also linked to the locking/unlocking/resetting issue was lights and rad fan. The lights would start to dim and then get bright while i had doors open and rad fan would blow after stopping the car when it was hot, slow down slightly then get back up to speed, up and down up and down.
To me: a battery or not enough charge situation.

(today i replaced the battery under the seat, I have both, rear hatch and seat batteries The one under the seat was totally flat, yet had been installed in jan 14 according to its sticker. Once the battery was replaced the key fob worked like a charm, not the door buttons, but lock and unlock from the key button was great. Also Lights light up bright and hold brightness and the rad fan stays at a constant speed but stays on for a very long time.. not sure if thats normal)

This caused a new issue: I noticed when the car was off, the wipers would just barely enable, im talking like a minor engaging sound and barely visible twitch out of the wiper arms, every 20-50 seconds. Now after 4 hours, key is back to crappy and locks suck, all the power issues again... HELP???

3) Under the dash the temperature controllers are messed up, I hear that you can get some servos and replace them your self. Any one know what parts i'd need for that? My local parts place doesnt have a part number for them and i dont want to go to porsche. Basically when the car has power/key engaged, theres the sound of a CD player trying to find a track ... CONSTANTLY!! its annoying. and the temp isnt regulated properly cause of it.

4) The fan for the inside ac and heat system for some reason doesnt start for about 1 minute after starting the car. Always. just turns on after 1 min and then works fine at whatever speed i put it at. but will never start immediately with the car. Tho today randomly started with the car once... I dont get it.

I've seearched online for DAYS now and cant find a straight answer to the issues. Battery draining thing is bugging me badly.

Thanks guys!

Cheers!

Marcone

[CdnRD]

I've had a Cayenne S for a few years and have experienced most of the issues you've mentioned - some have been resolved, some haven't and I live with them.
1. The highway fuel mileage on a CS is pretty good considering the weight of the vehicle and the size of the engine. My wife has a Volvo XC70 and the highway consumption is about the same. In the city the mileage is pretty poor. I've never seen 11.4l/100km as an average. I'm usually at about 13.5 and that's mostly on the highway. There might be something off with whatever controller calculates your mileage for display. If you're doing some city driving, 250km on a half tank sounds about right.
2 & 4. I've had a constant problem with battery drain since I got my CS. I've never noticed anything with the wipers but I've taken it in to an independent who wrongly diagnosed it as the stereo and the Porsche dealer who wrongly diagnosed it as the remote starter. Both disconnected the "offending" part and the battery still drained. I was able to reconnect the stereo but I'm going to have to have the installer reconnect the remote starter if I want to use it. I've decided to just live with. I replaced the battery with an AGM battery and that's made a big difference. I installed a hard line for a Ctek charger with the connector attached to the grill near the pan heater cord. I attached the leads to the mounting points for the boosting terminals under the hood (I had to solder extensions onto the wire that came with the Ctek). I only use the Ctek once a week or so in the winter just to ensure it doesn't discharge. Speaking of discharging, that's why your blower fan isn't turning on for a bit. It was always the first sign my battery had discharged. Next will be the battery warning when you start the car. Put a charger on it and hopefully the battery comes back to life. I'm willing to bet that you had gone for a longer drive prior to the time that the heater came on immediately or your CS was still warm as you had recharged your battery with the alternator.
3. I've got the same problem with the solenoids for the HVAC. I'm living with it for now because replacement of most of them require removal of the dash - not difficult but very time consuming!
Two other points. If the coolant pipes haven't been replaced with the updated aluminum ones, do it right away. It's a couple grand plus to have a shop do it or $600-700 and about ten hours of your time if you're capable of it. The other is that there's no provision for a block heater so you'll want to get a pan heater if you don't have one. There's an issue with icing up of early Cayenne V8's that leads to cylinder scoring, particularly in colder climates. The forums are full of horror stories and I've seen a few Cayennes for sale locally with blown engines. I'm not sure if the pan heater had anything to do with it but I've got 200,000km on mine (100k of which I put on) and no issues, and I park the car outside and regularly see -30 or colder.

[Marcone]

Hey! Thanks for the quick reply.
Crappy to see this many common issues....

Ill go in to a little more detail.

The car seems to do worse on the highway, i drive on the Hwy a lot and notice its mileage goes quick, but the display shows it does better on the HWY. When I drive on the Hwy I get it down to averaging at 11.5-13 highway and 15-17 in the city (as per the display in the dash) but if im getting 250 km to the tank.. thats 20L / 100KM??? even the specs on it shows it should get around 15 L / 100km combined average. So unless i have a hole in the tank (which i do not thankfully! ) something is terribly wrong with this vehicle.

Electrically, Yesterday i removed the batteries and replaced the one under the seat. Started the car for 30 seconds to make sure the spark plugs and coils i had installed at the same time worked. Worked.. great.. but Rad fan came on and didnt shut off for around 20 min. Engine was cool. Not driven.. After installing the batteries is when i noticed the slight figit of the wiper motor/blades. Im guessing something is not shutting off or some ground issues? Dunno. But now the key system is out of whack again. Im guessing the new battery is killed already.

Whats the battery warning when turning on the car? I have never gotten a warning. Are you talking about the centre where it says porsche in red on the display turning into a battery logo? That happens every time i put the key in and start the car?

SO, how do i know if i've had the coolant pipes replaced? Anyone have photos to show a before and after to better quickly see if im in the updated pile or the Effed pile? lol .

Also, i have 214,000 km on the car, bought it at 213, Figured 20k a year is a reasonably driven car. Not noticing any issues in the engine etc, Its a canadian car, possibly scored cylinders then? Ugh... scary.

Is the pan heater a necessity?

What a scary purchase.... gonna keep this all quiet from the wife... try and solve most of it myself.

Side note, anyone ever remove the WHOLE INTERIOR? Carpet smells and dealer left sun roof open once in the rain. Just want to pull the whole thing and clean it, suss out the electrical possible issues and put it back.. possible?

Cheers

[Marcone]

Oh, and to add to the MPG prob.

Some times when idling at a red light, the L/100km just climbs and climbs. alll the way up to 30 L / 100km, then i drive away and it starts to go down..

[fintstone]

I have a 2004 Turbo and am very happy with it other than the sad navigation system. It only has a single battery under the seat which I had to replace once without incident/problem. I have really not had any unexpected problems with mine other than low gas mileage (about 14-15 mpg) and having to replace the plastic coolant tubes. It does wear out tires quickly, but I use relatively soft compound and the vehicle is very heavy...so that is expected.

My key remotes also do not work from as great a distance as those for my other cars.

[Marcone]

Well.. i've sourced out some issues,

The fan at the front of the car will not stop till the under seat battery dies. I've removed its fuse till i can figure out what the reason is. Anyone know if there is a fan switch or something of the type that will fail and make the fan want to stay on always?

Secondly, i have a small twitch in the wiper motor even when the car is off and key is removed. Remove the fuse and it doesnt twitch(obviously) but i'd like to know what runs it? Could it be the moisture sensor that tells it to go harder when it rains? or a relay? lil help on this one cause its not my world of stuff.

Fuel mileage, Will replacing the o2 snensors help it out even if i dont have a check engine light? Can they work poorly but still show no fault?

Also, now i have an airbag fault (disconnected all the electrical inside the car and removed the carpets and such to fix a bunch of little crap) started the car with no seats in it to move it slightly and ... airbag error. Fixable? im guessing computer code reset maybe?

thanks guys!

[Mike80911]

The only thing I can ad is the heater fan taking a few seconds to come on is normal they all do it also the key fob is a pain if you press it to open the doors more than once you have to wait a few seconds to press it again to unlock the doors. My gas mileage always sucked but I live with it. If your driveshaft center support has not been replaced it will go bad same with fuel pumps and coils. Electrical issues seem to be non stop. The car eats tires and brakes for breakfast. Other than that I love my car it is also an 04 with 150,000 miles on it.

[fintstone]

Cooling fan problems - 9PA, 9PA1 (Cayenne, Cayenne S, Cayenne Turbo, Cayenne Turbo S) - RennTech.org Forums

[Marcone]

Thank you! Looks like the fan is the culprit? Damn it.. Im gonna run without it for the time being. Not over heating at all, its cold enough out now anyways.

Some issues have ironed out ... since the fan fuse is removed. I do still have a small issue with the alarm system where i lock the car.. go away and then come back and the blinking is not happening anymore. Press the unlock button and it unlocks back drivers side for sure, maybe passengers, but not the drivers door.. press the button again. locks and alarms.. then wait a second and it unlocks everything... weird...

So if im not getting faults in the instrument cluster, should i return my o2 sensors? or just put em in anyways... i could use the 500 dollars spent on better things. Looking for fuel savings with these sensors and if theyre fine unless i get a check engine then i dont need em?

[fintstone]

No problem. Might not be the fan...but certainly a possibility. Good troubleshooting info/schematic in that link. Certainly would run the battery down fast.

Actually it is more likely that one of your doors (back driver's side) is not actually locking with the others due to a problem with that door/lock.

I can't imagine bad O2 sensors unless you have a code flashing.

Good luck!

[Marcone]

Yeah. the doors are a weird thing right now.I can hear it unlocking the rear drivers door but not the drivers. When i open the drivers i hear a motor in the door doing something. Now it opens them all and the drivers door a millisecond later. Weird. Maybe the drivers door motor is going?

Thanks for the help so far guys ! These are interesting cars.