lewisweller

As you have good idle and smooth acceleration I doubt any leaks, what about your maf sensors? Could try cleaning them and also the MAP sensor. Can you log requested boost vs actual? Under boost would mean its being requested by the dme tune and not delivered so check your wastegates by pressurising the pipe (10psi) which is connected to n75 valve are not leaking and opening on there own. You can hear the wastegates opening together it should and no sound of air leaking should be heard. Do you have any pending dtc? What's the condition of spark plugs and coil. Do think your getting any knock/misfire under boost and it's pulling the boost down as a result?

Hard to say as they are little pieces of different shape and size rubber flexible tube pipes, they are mostly thicker tube pipes and none of mine had any damage so I'm sure yours are ok too except the vac pipe which is coming off the little valve which your need to secure with clip or change to new pipe which will make it a tight fit again as Porsche is not using any clips here as you can see.

Before thinking about a failed/cracked turbo.............. Check your Diverter valves. This sounds like a classic split diaphragm or vac pipe leak. Disconnect the DV's vacuum T piece located to the right side of the inlet Y pipe in front of the evap purge valve. Blow down each pipe they should all be closed and you should NOT be able to pass any air through them.

Thomas the little valve in your picture is the same little valve in my picture 2 3 & 4.

Found a suspicious looking sign of a leak where the PCV VENT pipe from each valve cover runs to the rear of the engine. This is the turbo vent line T. Maybe this is the cause of my stutter!! Will investigate tomorrow.

Thomas here is the info you need for this little vac pipes. You can reach and change the vac pipe no'1 by removing the passenger side Secondary air Pump then you can see the pipe to remove and replace. note the check valve should be tested also.

Starter is out and guess what it works just fine on the bench! WTF Took it apart and the brushes are like new plenty of life left in the old girl. reassembled after a clean up and retested perfect. so 3 possible issues: 1. The starter is ok until put under load 2. The engine is seized and the starter cant turn it over (tomorrow will turn the engine manually and disconnect the drive belt to spin alternator water pump and ac pulley to make sure nothing is seized) 3. The new battery plus jump starting of my spare battery and the Audi is also not enough power to crank the V8 over. Tomorrow will put it back in the car and try to crank it over direct off the starter with spare battery after I confirm the engine is turning manually freely. I got a theory of the sequence, the battery failed on Thursday and the car stalled, cranking wouldn't work as defective battery was too far gone, then the new battery came with a low state of charge and despite jump starting there isn't enough juice to get it to turn over?? I don't have a battery charger which is a huge PITA, so tomorrow have to buy one FFS.

What was puzzling this happened a fews days after the alternator was installed. I had started and driven the car several times since and noticed no issue. Where is the starter relay located and would or could a bad relay make the starter clunk click slightly and not crank over? The ignition switch crossed my mind but as my understanding would go I wouldn't get any click clunk partial crank at all if the ignition switch wasn't working? I'm inclined to think the starter is jammed or the engine has an issue which is preventing rotation heaven forbid like seized up!? As the starter removal is looking like a 1 hour job now I'm so used to working on this PIG I think just for the hell of it im going in there anyway. I intend to remove, bench test and strip and clean all components of the starter, assuming good function will not be replacing it. Hey thomas will be replacing my vacuum pipe at the back too lol will take some snaps for you, maybe your next diy job?

Got the new battery as a warranty replacement for the 6 month old one. They sent it to be tested they said, it failed the test but no details why exactly given. Put in the new battery Varta brand 110amp 900cca the Proper battery I'm sure just like the old one was too. All I get is click and a minute turn like 1/4" of the timing chain when view led through through oil filler cap removed. So wtf!! I even tried to jump start of the audi again and same click, dash lights flash off. So what would cause this? Stalled engine which wouldn't crank to start, a failed battery replaced and still no start even with jumpers? Possibles: 1. New battery no charge (measures just 12volts which I know is low but even jumpers of audi didn't crank it) 2. Starter motor is dead, bad battery is a coincidence or a by product visa versa? But Why did the car stall? 3. Other possible fault that could stop it cracking are?? But still allow it to engage and turn a few mm. Losing the will to live...............

No warning on dash, no indication it was going to die, started and ran Ok about 15 mins before when I left my business partners office just a few kms away. I just whipped it out of the car earlier, no signs of leaks or damage, looks like a brand new battery as you would expect. Will try to blag a warranty replacement as it's only six months old, bit cheeky but worth a crack. Cost new is 750dhs about $200.

Can do, without the maf connected the dme will revert to a reference map for air volume based on the MAP sensor pressure and throttle position amongst other sensors inputs. Short term test should be fine, long term not recommended. You mentioned the more is no more oil contamination on the driver side maf sensor which is good, what is not known is whether any of the maf sensors you have are faulty or good. The Porsche test is to measure 1.1volts dc when ignition is on and engine off. I am getting my new battery tomorrow morning and still hoping my issues might be helped with a new battery as obviously something is wrong with this one probably caused by the alternator. I will see how it runs and then intend to do the maf sensor test myself. I will document how and where to measure on the back of the connector and post for you.

Hi Thomas. If this vac pipe is off again and you didn't get a chance to find some of the clips I suggested, just get some wire and loop it round the pipe and twist tight with some pliers. Which maf have you got fitted now? Old, aftermarket new or used oem?

As the fuel tanks access covers are both inside the vehicle and included is both pumps the filter and regulator I highly doubt you would smell it outside and not inside the vehicle if the rubber gaskets were leaking. More likely possibilities are exhaust leak, evap canister leak, fuel cap (although its the other side) and other associated fuel piping.

Today recalibrated the air suspension ride height as the front was sitting too low following the alternator works. On the way home earlier got near the house and coasted to the roundabout and felt the steering go heavy and then realised the car had shut off mid cornering. Managed to roll up the front of my building and dump it. Tried to restart and starter does a half turn and stops, classic dead battery. I tried to jump start of the audi but whilst doing so I had the Vagcom do a full scan, no surprise some codes all relating to low voltage fuse 30, no communication, steering angle sensor ambient air temp fault etc all new codes never seen before, after leaving it on the jumpers tried again and watched the voltage drop to 8volts and split second cranking and nothing. So my new battery in Feb is dead. Im thinking the alternator failure also screwed up the battery over the last 6 months and dropped a cell. Will chuck in a new one on saturday and see all is ok. What's weird is why did the car cut out whilst driving without warning? Could have been a dangerous situation.

Yep bonnet switch then, I found a porsche 996 or something bonnet micro switch with harness and plug, the plug looked exactly like the one you have hanging from the top disconnected so I gotta say it must be. Strange the dash doesn't warn the bonnet is open being as the plug is disconnected? Maybe open circuit it doesn't see it as a fault weird no fail safe? I see the centre grille is a separate part so maybe it can be removed? Likely some tabs clips and it's a push in fitment like most Vag group grilles and mesh. Maybe someone can chime in and tell if the centre grille can be removed independent of the bumper?

Well the alternator is done! What a total nightmare of a job, the new (reconditioned) alternator was marginally bigger than the old one and I spent literally 2 hrs getting it back in, hands are a mess right now. Started her up with the assistance of a battery off my diesel generator, and after a few mins disconnected the donor battery and tested the charging voltage a healthy stable 13.6volts, made the whole ordeal worth it. Topping off coolant tomorrow and clear codes, throttle alignment etc and a quick wash before going for a blast to see how it runs now and excited to see if the other gremlins have actually disappeared or not. Couple things to note, the coolant pipe connector on the new Alternator was different and I had to modify it to fit the bolt hole (third picture) and it also was orientated differently meaning it faced up and towards the right fender (second picture new alternator and connectors reused) as opposed to towards the front bumper(first picture original alternator fitment). Luckily by opening out the hole on the plastic retaining as much metal insert as possible for strength, cutting the spigot slightly shorter and rerouting the coolant hose I was able to reuse the existing fittings with just new O-rings. Porsche here is shut for 4 days Muslim holiday, (I wasn't being stingy reusing the parts and I wasn't waiting 4 days either..............impatient). I also did not reinstall the pointless extra half moon shape metal part that bolts on the alternator and curves around the pulley, I just made sure the pipes etc all were secure and can't rub or touch any rotating parts. The boost hoses removed I replaced the O-rings whilst there and I also replaced front brake pads for brembo (pagid) originals, and the passenger side upper suspension arm which had play in it and as you can see the ball joint socket was oval! (Picture four) I broke it getting it out, had to beat it, tight as ****. Thanks to posting members for support and I hope none of you ever have to do this job.

Only other possibility as I can't see any parking sensors is either the bonnet latch micro switch (alarm code related maybe) or the front fog lights wiring harness? I looked at every diagram and that's all there is.

I would go for the ambient air temperature sensor. Item 2 in the Porsche manual for a 2003 cayenne. What does the dash temp read?

Despite the dangers of fuelling with the engine on and disrupting the fuel tanks operating pressure, here in the middle east lazy culture and the extreme heat, no one turns off their engine when refuelling or even gets out of their cars. I personally haven't had a code or related fault from refuelling with the engine on not to say its not possible. Maybe different country emissions regulations can make a code pop if refuelling whilst running but it would be the first I heard.

That's a ball ache. Must have a broken tooth or worn down. My front diff whines a little at 120kph and I just ignore it (drive at 118 or 122 and can't hear it really, ignorance is bliss), I swapped the fluid twice and no metal or anything. I read the front bearing just likes to whine at certain speeds. Some people even had this whine since they had the car at low km from new! Gotta love these pigs

Unlikely fuel will create a single cylinder misfire so first thing is to switch ignition coil from 7 with 6 and see if the fault moves? If not put it back and move the spark plug instead. Rough running at all rpm is more likely ignition related. The fuel tank purge valve is renowned for causing problems with start up after refuelling but usually comes with a 0441 code, also possible is evap canister clogged saturated or something. Purge valve is in red on attached diagram. Pelican Parts has a good DIY. I changed mine already, pretty straight forward job, but I had the code to confirm the problem.

The alternator is out and omg what a lovely job it was to remove. I didn't put the front end into service position but I hazard a guess it may have made life a little easier. The alternator came out of the wheel arch where the air box usually sits, I managed to catch all my Coolant which was new a few months back so bet your *** it's going back in! New Alternator arrives tomorrow via mothers express vacation delivery care Package...... As you can see from the picture the inside insulation has crumbled and melted into a paste. Yuck, I cleaned it up ready to send back as eBay item was exchange type deal.

Under load yes but even if accelerating under half Throttle from low rpm up as the boost comes in it will kangaroo through the rev range, my wife feels it when she drives it and passengers notice it so its not like it subtle and in my OCD head even....... lol. I'm excited about the new alternator and how a more stable electrical system in this very pernickity car will make improvements. How sad, I'm actually excited.........

Update on this......... the replaced check valves didn't fix the hesitation problem even though both check valves were faulty!! Alternator just failed so looking into the possibility that charging voltage stability may have something to do with the problem. New Alternator going on this week.

Got the car to my warehouse without breaking down, what I did notice is how dramatic the running difference is with alternator not charging and the battery dying, the idle was up around 1000rpm fluctuating and acceleration was noticeably laboured with gear shifts a bit abrupt even though I drove it very smooth and tickled the throttle all the way coasting to slow and barely touched the brake. so im really hoping with a fresh alternator and the already nearly new battery a lot, if not all my remaining gremlins are going to vanish! This list is: Hesitation under acceleration "Check tail light" when I touch the brake random "check licence plate light" "four wheel drive system faulty" AC compressor recently cutting out or wont cut in when first starting engine no fault codes except the recurring "Electrical load intervention" which I now think is cryptic for "fyi car owner one day your alternator will fail" .................lol