lewisweller

28 minutes ago, PigNib said:

Success!!!!!!!!!   ?   !!!!

 

After replacing the coil packs I have been unable to recreate this problem!

 

I've been able to recreate the problem 90% of the time and have experienced it probably 200 times but it happened almost 100% of the time in Summer.

I've driven the car 8 times after replacing the coil packs and have not been able to get the charge/alt warning light to re-appear, even when putting the hot car in gear immediately after starting... the method i could get it to stick at 12v for a LONG time... (up to 40 minutes) and no A/C during that time.

 

I've tried to make it fail the last couple days and stick at 12V and I can't... something about changing the coil packs appears to have fixed the problem.

4 of the remaining 7 coil packs were older/non-branded... 3 of the older ones were newer Beru but i replaced them anyway and kept the old Berus as spares.

 

I'll keep testing and report back again... I can't explain why... I may try to test the coil packs... ohms? not sure how...

 

 

 

Well done sir!

Yet another electrical gremlin for the cayenne and another problem fixed by coil pack replacement although who would have guessed that without prior knowledge or experience it can cause alternator charging issues?? 

Do enjoy. 

7 hours ago, PigNib said:

I had a leaking radiator overflow reservoir to replace this weekend. 

Job went fine until the very last step, clamping down the headlight.

Ended up breaking the headlight bracket ;<

 

To the point: I spent another hour or so locating the module which is exactly where you thought it was.

The bracket that holds it uses clips and one bolt to hold it to the frame. Of course the bolt is in the one corner I can't get to without removing the lower dash.

I spent most of the time trying to remove the plastic lug that holds the ignition.. Everyone says it just takes a flathead uses the notches.

Much time and lots of slips/scratches later I just couldn't remove it. I suppose I need to buy the special tool or a replacement part and just break it.

 

I was able to get the part number off the module so my plan is to locate the tool, replacement plastic nut, and module and try again.

 

Meanwhile the problem persists... never happens in the morning until it runs awhile... doesn't even have to be THAT long... 5-10 minutes... next start 12v...

 

I'm thinking more and more it's not the module but I'm willing to go ahead and try it since I haven't heard any other logical explanation.

 

I don't know if that module will require some coding to your car? Assuming you don't have durametric or vagcom? Often if you buy a module from exactly the same model spec options etc etc must be Exactly!! it wont need coding. I also wonder if this will fix it, have you considered high resistance in some wiring which increases as it heats up? Question is what wiring? Minefield .......

2 minutes ago, roberta berks said:

Right.Since the car has only 45k miles and runs great when it does run without symptoms or faults,I'm leaning towards some little connector that's corroded from sitting in humid Florida.It was that when I swapped out the rear convenience module a few months ago after gremlins started appearing and fixed without a dura or piwis.Maybe alarm module since it sits on top of rear convenience,I dont know.Real PITA vehicle.

Kessy module is under the dash just up above the accelerator pedal. I think the module next to the rear comfort control module is the level control module? 

21 minutes ago, roberta berks said:

 

Sure, thank you.It does not show symptoms of hesitation or start for a second then die out that usually relates to fuel problem.(when running). Just intermediate fast crank like the key is not recognized (tried both keys). Some electrical gremlin again perhaps?That is all Ive had with this car.Car does sit for months at a time.Any other thoughts are appreciated

I would have thought it wouldn't crank if the immobilizer was the issue? Not quite sure. 

I'm still not sold on it not being a fuel issue perhaps. Really only testing and ruling out things will get you closer to the cause without fault codes to help guide you. 

Just now, roberta berks said:

Thanks.Runs great when it starts.No fault codes.

Fuel pressure is a possibility. There is a fuel pressure regulator which is supposed to hold 3 bar after ten minutes when engine is stopped IIRC, if that fails you go to crank and don't have any fuel pressure available, hence long crank to build pressure then it starts. I remember also the fuel filter has a non return valve in it which can fail. Also fuel pumps are notorious for being a pain, weak pumps, leaky pipes, clogged suction screens etc etc. I've been inside my tank a few times and replaced all these items on my 06 ctt when I had it. 

Testing fuel pressure requires a fuel pressure test kit with correct Schrader fittings and a specific procedure. 

Just now, roberta berks said:

What would cause low compression on a 45k mile Cayenne that ran great?

Ran great (past tense) or stills runs great (when it starts)?

A list of possibilities but yes a good running low mileage engine shouldn't have these problems.

Got any fault codes? 

The symptoms are too vague to narrow down a cause yet.  

2 hours ago, roberta berks said:

Have a problem once and a while when car sits for a month or so.I come back to it a couple times and sometimes it finally it starts.New battery and new key battery's. No second trunk battery.Seems like it cranks faster too.Key programming?

Erm im hedging a bet the battery(s) are ok if cranking is faster than normal.

Low compression can cause faster cranking and no start or hard starting symptoms. 

Would suggest doing compression test first. 

15 hours ago, millerchris85 said:

It appears my oil guide housing is leaking (2008 Cayenne TT).  From reading others' experiences, it is a painful repair.  It appears to leak more when the car has been sitting; if driven daily, the leak appears minimal.

 

Are there any strategies that have worked besides dropping the subframe and resealing it?  There were comments of poor bolt choice for 08 and possibly other years - might bolt tightening or replacement help?

 

I may try a different oil weight; currently using Mobil OW-40.

 

Any advice would be greatly appreciated!  Pretty frustrated with this one.

Generally tightening (torque evenly) the bolts can either reduce or stop leaks or make it worse, bit of a gamble. 

You could try a thicker oil depending on your climate? Most climates don't need a 0w oil. 15w40 can work in warmer climates, even a 10w40 is fine down to -10 or lower. 

These stop leak products are not advisable IMHO. Unless the car isn't a "keeper". 

You may be putting off the inevitable mate, need to be dropped and resealed properly? 

7 hours ago, PigNib said:

There!

 

Notice your diagram's part 15 is the same as where my diagram's parts 11 & 12  (relay terminals) fit.

The website shows all the relays in 11 and 13.... relays in 13 are mostly show in the screncap...

servotronic, rear lid lock, air suspension relay, fuel filler flap, etc.

 

You would think you could find a document showing the location of those but I've watched tons of videos and watched lots of websites  with diagrams that seem to show all fuse boxes and relays EXCEPT for those..

 

 

Well well well. Item number 6. 

It's actually next to the kessy unit under the dash (drivers side) (lhd) probably right of the accelerator peddle and up about 40cm. 

6 hours ago, PigNib said:

Getting closer!

 

Using the website you used (good resource!) I found another diagram that shows the same carrier part for the control unit attached to these relays.

Unfortunately with all my searching and knowing what relays are next to the control unit i STILL can't find out where it is yet.

I guess these relays don't need to be replaced often.

I'll keep looking... as soon as i know i can get to the control unit I'll buy a replacement and try it.

SURELY if there are relays near by it can't be THAT hard to access.

 

Thanks for helping even though you don't even have a Cayenne anymore!

2019-09-19_07-38-14.snagproj 377.28 kB · 1 download

Phone Can't open that picture for some reason? 

On 7/25/2019 at 8:55 PM, ekstroemtj said:

It’s an old discussion but maybe somebody is willing to tell me what is the function of this pump? The additional electric one. Only feeded by the „rest“ Button or it’s running all the time/ specially when temp gets very high? Thank you

Thomas, the pump literally is used to make sure the hot coolant flows back and circulates properly to the heater matrix(s)to keep passengers warm, it also send it back to the rear heater matrix (if fitted). Some cayenne have a.c. evaporator and heater matrix in the boot as well as in the lower dash. "Four zone climate control" option I believe it was called. 

The "rest" button just runs this pump when the engine is off and the passengers are asking for warm air still from the interior fan hence hot coolant is required to circulate by electric pump. Hello from the UK my friend. 

6 hours ago, PigNib said:

Wow this is the first I’ve seen that suggested. I’ve read a half dozen or so people on various boards having what appears to be the same problem. Several times the battery and alternator were not the root cause. A couple just cut the exciter wire to force it to always charge.

This part is $550 new but can be had for $30-50 on eBay. That tells me not many people replace the part or need one which IMO reinforces the theory that may be it.
I usually think of cold being a problem with circuits (solder joints) but heat could do that too or maybe skew a discrete part like a resistor or capacitor out of spec.

It’s a long shot but I’d be willing to buy one and try.

Where the heck is this thing? Hella-hard place I’m sure 😉

I’d much rather take apart a dash than work the same amount of time in the engine compartment.

I also would like to test the exciter wire voltage. Anyone know if it’s accessible without removing anything difficult?

I’m planning on hauling a camper with Electeic brakes end of October and would love to figure this out before then.

Also if anyone knows of what to look for in the Porsche tool my Porsche shop (not dealership) is always willing to do that kind of thing for free if I do the research and tell them what to look for.

Thanks for the reply!

(Off to search for my own answers)


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I've looked and can't locate yet where that module is! I've got a hunch it's under the seat next to battery?? I don't have a cayenne any longer so I can't check myself. Definitely worth a cheap used eBay punt if you can locate where it is. PLEASE BE AWARE ... the module is different depending on MY and options fitted. Check first. 

If you find your module take it apart and check first for something obvious, I would, but your risk. 

A clue is that it sits in a bracket part 15 which looks to be mounted horizontally which means it won't be hanging around in the dash I very much doubt, it got to mounted somewhere quite large and flat!!! The TCM transmission control module was under the passenger (LHD) seat I know for sure, I removed it and tested mine! It might be next to the TCM? Can't remember. Flip both seats back and check. Good luck. 

On 9/15/2019 at 5:01 PM, PigNib said:

Sending this duplicate response from similar one on rennlist:

Joining this thread not to hijack it but hope to help.
I have these exact problems/symptoms.

I wish i remembered exactly when it started and what was done before/after. I’ve had this problem for over a year. It seemed to first surface last summer ( we get hot ones in Arkansas ). I had a starter problem ?before? This happened and had that replaced after replacing the battery first (it was old and was hoping that was all it was. I’ve also had headlight problems ( I have xeon) flickering and going out because of the known problem of wire coatings disintegrating in the bulb housings. I’ve fixed that with liquid tape (I think) and do not think it is related.

The below statements are repeatable and almost always consistent.

The first start of the day the volts (dash gauge) always jump to 14 quickly and the A/C and fan kick on fine.

Once the bolts hit 14, regardless of the condition, they Have NEVER dropped back to 12 while driving or while the engine remains running. If making a quick trip in somewhere I sometimes just let it idle so I don’t have to restart it and wait for the volts to go back to 14.

After driving for a while and the Engine gets hot the next time I start it (within an hour or two) the volts sit at 12 then eventually (usually within 90 secs) go back to 14 and the AC and fan kicks on. Until the dash reads 14 the A/C fan won’t blow. Revving the engine, shutting off electrical things, etc. do not seem to make a difference.

When starting it hot hot and volts read 12 and I put the car in gear and drive the volts do not go back to 14 nearly as fast. During this time no AC fan and I have to roll down the windows in the 100 degree heat. The voltage almost always go back to 14. Sometimes quickly (2-3 minutes) but I’ve driven for 30 before without it returning to 14. Once that happens (driving without letting volts get to 14 first) stopping the engine, removing the key, then re-starting doesn’t seem to get the volts back to 14 within the 90 seconds like it normally does with a hot engine. I only do this if I absent minded lay forget to let volts climb befoee
putting it in gear.

Haven’t started diagnosing yet but I think this would be a LOT easier to figure out if we knew the computer if then else flowchart for how the computer (sends) voltage to the exciter wire. I don’t see anything in the diagram inline for the exciter wire. I expect if I cut my exciter wire ( forcing the alternator to think it was under voltage) it would engage and I would always get 14 volts. If true it really comes down to what is happening while the voltage is at 12v and the car is running that prevents the exciter wire from reducing voltage below what it needs to engage?

Maybe I still don’t understand how the charging circuit works. I hear that all
the electrical stuff really pulls from the battery, not the alternator directly. And the alternator isn’t always charging the batter, only when it drops below X volts. I assume this is to keep from overcharging the batter or just sparing the life of the alternator?

if that’s true what condition would keep the ac fan from working ( computer shuts down because of reading low battery voltage ) but at the same time sending enough voltage to the exciter wire to keep the alternator from engaging? Those two things seems opposing. What damage would be done by just removing the exciter wire?

Ill Try to gather more evidence. My
porsche mechanic ( no dealers but he only does Porsche and lots of cayennes) says he has NEVER had to replace an alternator.

Thanks!

Jeff in Arkansas


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Control unit issue perhaps? 

It seems this module is responsible for charging and permissions to run certain things like a.c. fan, turning off things to save power if required etc. And must also be the control for the "exciter" cable. 

Diagnostic required to test this module operationally. 

I remember reading at full throttle it also cuts off the alternator to deliver full power acceleration! 

On 3/1/2019 at 9:59 PM, Graeme Tate said:

The car is a facelift 2007-2008 cayenne S, the only fault code it is showing Is P0016 camshaft crankshaft correlation error

Check the crankshaft sensor. Sensor End should be clean and not damaged. Check the resistance also. 

Other correlation issues turned out to be timing chain issues, stretching, jumping a tooth, tensioners snapped/collapsed etc etc. 

More diagnostics required........

If the fuel was the root cause, dirt in tank, filter clogged now ?? How that relates to p0016 idk ?? 

On 8/18/2019 at 9:11 PM, WillMo said:

My 06 Turbo cooling is acting weird just today. At idle or slow speeds it's always on 180. On the highway it seems to warm to 190-200. Stop and it cools right down to 180. Today on rhe highway the check coolant came on and temps were 210 to maybe 215. Stopped, only took maybe 1/3 gallon to top off. Still seemed to run 210 or so the next 10 minutes to home. Idled and it dropped back to 180. Any thoughts on what's causing this?

If air is in the system you can tell cos in the morning after its cooled completely it will be low level in expansion tank and need topping up. This may take a few days of topping off to get full in my experience. But why? Had work done recently? 

Otherwise the turbo coolant T's at back of engine are a possible leak point and the dreaded pipes under the manifold or the water pump itself or alternator, the list goes on.....

I'll list below the overheating possible causes I know of: 

1. Head gasket failure I had, would over heat at idle due to low relative coolant flow and hot combustion gases entering the coolant. 

2. Serpentine belt slippage on water pump 

3. Water pump impeller blades broke or excess clearances reducing pumping performance. 

4. Thermostat or fan switching control 

5. Fans not running 

6. Rad blocked. 

7. Air locks, hard to bleed this engine manually, best to let self bleed, cool to stone cold and top off daily until full.  

8. ECT sensor faulty

My guess is water pump, my theory, blades are snapped/clearances are incorrect between impeller and housing (worn pump bearings allows contact of impeller to housing) .

At idle flow is enough to cool engine and turbo's, at speed the heat is too much and the flow is still poor due to the blades snapped. 

You would amazed by the heat difference from idle compared to 3k rpm. 

On 8/3/2019 at 7:39 PM, Clean-d Ramenwasser said:

Dear all,

 

I am new here, just got my first porsche and did something stupid 🤐 . I changed the oil but forgot to disable the levelling. Now after a short drive the car says it is at it's "normal level" but the rear right side is at his highest possible level. The Chassis warning is on also......

Now i read a lot on internet that its possible to re-calibrate the system with the durametric, is this correct? someone has experience with this system?

Thanks in advance.

 

IIRC the durametric cant do it, maybe a revision is out by now  I don't know. I used vagcom to do mine as the module is basically from the vw Touareq. It will depend on the year, up to 2006 will work. After that I'm not sure it works with vagcom. 

On 8/28/2019 at 4:00 AM, John Komar said:

It's alive ! 

After spending the weekend going through wiring and grounds it still would not run. So even though I put in new sensors I decided to pull them out and test them to see if they were working and unceremoniously they all checked out. But out of curiosity I grabbed an old Bosch cam positioning sensor I had and while holding it next to the (new) Bremi cam positioning sensor something didn't look correct. I decided to measure them and the Bremi cam positioning sensor was at least 1mm shorter than the Bosch sensor. So I replaced the cam sensors with Bosch sensors and wouldn't you know it, it fired right up. 

It most likely wasn't throwing any codes because the sensors did work I just think that the 1mm made the difference. Had I had an oscilloscope to connect to the sensor while cranking this could have been solved much quicker. Now why it ran for a while I have no idea it could have been just on the upper tolerance limit and with expansion and contraction it pushed it to its outside limit. 

 

The Bremi cam sensor P/N: B5-99660610602 was and still is listed as a direct replacement for the Bosch P/N 0232103022 at half the cost but after this experience I'll buy the Bosch part. 

 

Thanks for watching and just maybe this little nugget of frustration will help someone. 

 

 

Nice find and kudos for not taking a stiff one from the stealership. Who knows what new parts or control modules you might have ended up with lol. 

3 hours ago, Corvetteboy6988 said:

Thanks for the feedback, I will be doing the front sway bar endlinks here in a day or so, so I will know if its that.  Are you suggestion the ones by the front bumper, the 2 large sway bar bushings that are connect to the frame, was a problem you had?  I will look at those tonight, they are hard to see without remove the belly pan, so didnt check them previously, although the little I can see of the outside end of them, the "look" ok.  I have also pushed up on the stabilizar bar to see if there is excessive movement in them, and there isnt.

Maybe Ill just do these as well, after the end links, as I have read one other mentioning these although they look good, can be bad, allowing the stablizer bar to hit the frame mount.  Then, move on to the LCA's after those to things.

When I disconnet the endlinks to change them, I will see how the bar bushing act when moving.

 

yep, no whine or other noises from the front diff, just this bit of movement when I tug on them from under the car.

 

Yeah the two centre arb bushes and end links were worn on mine, you gotta remove a plastic cover piece and the under tray to see the Bushes IIRC. 

On 5/2/2019 at 5:13 PM, wtsnt said:

I had my 2008 Cayenne S in the shop for front wheel bearing replacement.  The shop told me that my steering rack was leaking and noted that a replacement rack was about $2400.  I looked through some Cayenne forums and have noted that there appear to be a number of companies that rebuild racks in the $500-$600 range.  Has anyone replaced a steering rack with a rebuilt unit?  Also, how do you tell if your Cayenne has Servotronic steering or not?

 

Thanks,

 

Terry Watson

 

I had a leaking rack end seal and bought one from a hydraulic seal shop for a few quid, I did post all the details pictures on here back in 2017. I'll try and find it. Where is you leak? 

Edit found it. 

I would be looking at bottom ball joints for play or control arm bushes or arb links. Remember when loaded they might seem ok, if you disconnect arb links for example they can then prove to be sloppy and worn. The diff output bearing movement isn't normal but I don't think you would feel that driving along unless they whine like mine did (you said they didn't), but certainly coming to a abrupt stop the diff bearings and CV's are going to get some torque stresses and clunk when worn.  

I had a clunk on mine and found one bottom ball joint nut wasnt tight following an engine/transmission drop for a new torque converter seal. 

Before that Pretty sure I replaced the front arb bushes also that run near the front bumper bar. This was another time and front end clunk was the symptom over fast speed bumps and potholes. 

Get the disc checked on the car with dti (dial test indicator), if result shows they are warped, remove discs and recheck the disc and the hubs separately. You need to identity where the issue is. 

If the hubs pass the dti test and the discs fail then this points to two issues, the discs are poor quality and susceptible to warping (bad batch or metal heat treatment process), or the caliper/pad is not functioning correctly, sticking binding, uneven pressure etc. 

On my ctt the brakes would squeal and I regularly had to strip off pads and clean and apply copper grease and also anti-squeal fluid to pad surface. I wonder if your brakes are binding and causing over heating this may explain the previous hub warping issues as well? 

Trying to think outside the box now without throwing more parts and money at it for the same reoccurrences. 

23 hours ago, HBP said:

Just wanted to give a quick update to this thread.  Picked up the supplies and drained the new fluid I'd put in almost 2 months ago.  Was a little surprised at how dark it was as shown in the pic below.  I can see why some do the flush now.  

 

It was fairly cold in the garage and the transfer case was cold, as soon as I took the fill plug out fluid started coming out.  So I'm wondering if maybe the reason I wasn't able to refill to the top last time was because I'd warmed the transfer case up before draining and that expanded the case and increased the volume?  This time when I refilled, it did come out the fill plug and I had just a bit left in the container.

 

 

I did mine drain refill a few times. It always drained about 950ml and refilled about the same. 

As long as it comes out of the fill plug it's enough. Let it drain any excess from the fill plug. Level car is important. 

14 hours ago, Stryker said:

 

Hey guys, went out to the car this morning and noticed my brake lights were on and was greeted with a flat battery, anyone had any experience of this?

 

Cheers!

 

 

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Could be the pedal switch faulty, try disconnecting the plug and see if the BL go off. Don't remove the BL switch unless you have a new one, they are a one time fit affair apparently. Other issues can be the rear comfort control module faults. 

Get the battery charged and read the fault codes I guess would be a start also. 

2 hours ago, 9552T500 said:

thanks for the comment lewisweller. i think there is nothing wrong  to answer a question after having it figuring oneself, when prior either keyword search on a forum did not show results, or couple of days pass wo any suggestion to some problem stated. Reading all posts seems super inefficient, but a search function , blocking typically after 1-2 queries suggests that this is desired here. 

However, vapor of a leaking engine as root cause makes totally sense - especially for a 120k engine. i will keep this in mind for the next more serious engine work down the road. 

 

Yeah it tickled my (wicked) British humour button, I didn't mean any offence. 

I often answer my own questions on this forum as despite the vastness of the Web etc amazingly hard to find info on some stuff, but it's good for someone else in future to have the answer too. 

What I do detest is the thread which lasts 8 pages and result in ......... No conclusion and goes dead arrggghhhhhh how annoying.  

39 minutes ago, 9552T500 said:

problem solved and lesson learned. cabin filters can be as important as the respirators for the crew of eight under the hood, and might need as frequent attention:) Wonder why nobody came up with a suggestion, and searching by keywords for air condition smell does not yield any results. However, Just clening out makes a big difference. new one on the way....

That's funny answering your own post asking why no one thought about the filter and neither had you at that point. Hehe. I jest, not attacking. ......

It's probably likely you got oil leak ( common valve cover gaskets leak) which is getting burnt off and drawn through the AC. A new filter is freshly carbon impregnated so it absorbs the smell to an extent. Like airplane seats and farts.