Snipe656

i was trying to emulate what I thought they described. So what I thought they were saying is by using triptronic they are forcing the vehicle to stay in 8th gear so long as they basically do not floor it and force it to downshift. Since I never use the triptronic my method of testing was get up to the test speed of 75mph then engage triptronic via either moving the shifter over or using the paddles. I really had no reason to then downshift into 7th and back into 8th, guess in my mind it ensured I was in triptronic. Once I was in triptronic and in 8th I then figured out how much throttle you can give before a downshift is forced and that throttle level is quite a lot. Once I had that down I then tried 8th gear in triptronic from 75mph and observed while it accelerates it is not fast but it makes and holds 0.5 BAR of boost.

My vehicle has had no known issues since engine replacement 4-5k miles ago. So my assumption is that behavior is how it should be and his behavior of zero boost is not how it should be.

How that clarifies, kind of a pain replying on here via my iPhone and chrome so hard to read back and proof read to fix any mistakes on my part.

caronsd

Thank you for posting the video - definitely what I am seeing. I'll try to shoot one myself this weekend. This discussion thread will also help when the time comes to talk to my SA. Thankfully, the Service Department at my dealership of choice (Manager, Advisers, and Techs) seem to be up on the issues and have worked well with/for me in the past.

Snipe656

good luck. I got the impression after my experience that the mother ship sure does a bad job of communicating known issues downstream to the dealers. I had bad luck in that first two dealers I went too turned out to be horrible selections for needing people who listen and diagnose things.

moosehead

^Thanks Snipe much appreciated. Glad you got yours sorted after what must have been a frustrating or maddening experience.

cdog533

Based on your post, I tried lugging it in 7th and 8th gear @ 75 mph this morning - and got exactly YOUR results.

- Car made about 7 lbs. of boost (about .5 bar) in 8th gear and boost level stayed there no matter how much I lugged it (i.e. even putting it in 8th at 45 mph). Boost probably would have went up as rpms creeped up if I has stayed on it.

- In 7th gear car made more like 9 lbs of boost at full throttle @ 75 mph (lugging it a bit), staying at 9 lbs. but going steadily up as the rpms creeped up.

This is odd as its completely different than my previous observations. I know that during my prior test, it was reading zero boost at WOT in the higher gears, which I thought was different than other turbo cars I've owned, hence my theory about detonation. I remember feathering the throttle which would get it to make a little boost, but once I went past say 10% throttle, boost would drop to zero and STAY there even with the throttle wide open.

So, there is something triggering low-boost situations in higher gears, but no one knows what it is....

EDIT: Further testing had been inconsistent. See my videos below. My car has bouts of both 'no-boost' and 'full boost' seemingly at random.

Snipe656

If the zero boost ever happens again try to pay attention to the exhaust tone. When the car is attempting to back out all boost via the wastegates you will have a tone from the exhaust that has more base to it. Of course there could be programming criteria to back it out when in that gear, rpm, and some other criteria I did not meet yesterday.

I could notice the wastegates backing everything out via exhaust tone and easiest for me to notice just at partial throttle. Every time I noticed it I usually blurted out some choice words about the car that included "the problem is happening again!". But my wife never could notice the sound difference, think I was noticing it because was struggling so much to find a details I could give the dealerships in hopes of them recognizing the vehicle had a problem. I think I put ~7k miles on mine over a few months with the problem happening, so I got way too intimate with the issue.

caronsd

It's one of those wonderful intermittent problems... I drove the GTS again this morning and found that it boosted "correctly" as well - no drop-off in boost as I observed a few days ago. Still running the same tank of fuel (no fill-ups since), so the change in response is not due to an actual (real) difference in fuel quality. It's one of those things where I'll have to always be ready to document the occurrence as it's not clear what triggers to vehicle to act in such a manner,

Snipe656

I never could find a sure fire way to make it always trigger in mine. The one thing that would often make it trigger was if I had to drive 40 or more miles in my afternoon routine. It would always trigger if I went on a long road trip but usually the bulk of my driving is 20-30 mile one way trips. This turned out to be part of the problem with because the dealerships that I went to apparently are mindful to not put too many miles on someones car. With mine the occurrences became more and more often so became easier to end up being able to make a bunch of videos then later sort through those to figure out which ones to provide to the dealer along with detailed descriptions of what the videos were showing.

John Welch.

Engine replacement as a "solution". Somebody is confused. You know what else would be a "solution"? Entire car replacement.

Something, in the hundreds of parts that were replaced when the engine was swapped is not working correctly. I can't believe that anybody thought this was the way to diagnose something.

Sure, the problem is gone, but it wasn't fixed.

Snipe656

But if the problem is internal to the engine .... would you rather the dealership tear apart the engine trying to fix it or replace the entire engine? Not like I was given a choice anyway. Buying back the entire vehicle usually is not an option they give and requires Lemon Law(which I was just one step away from being able to apply but that is because bought in Louisiana, live in Texas, so had to follow Louisiana's Lemon Law).

Here we are a year later since these problems started getting reported by owners and I am willing to bet Porsche still lacks a solution since August when they elected to replace my engine. I am sure that $15-20k cost was not one they want to just willingly eat if they have not been exhausting various diagnostic methods and other hopeful fixes.

stiles_s

I've been keeping an eye on this thread as I'm only 1600Mi into my '16 Cayenne S. I've taken a few longer trips w/no issues.

FWIW, since we're all armchair quarterbacking, this sure sounds like a software thing and not a hardware thing.

Software will commonly pull boost when it detects a dangerous state. Could be engine temp, detonation, or even some sort of fault in the driveline. FWIW, it's also quite common for automatic equipped cars to pull timing and boost at shift time. I wonder if there's some sort of lag happening relating to shifts.

Regardless, I'm optimistic that it'll be solvable w/software.

Snipe656

i stumbled on an old email I sent to a friend back after I had an almost two hour meeting about my vehicle having this problem with the regional guy. It is a problem internal to some engines and at the time and I will assume still they do not know why some of the engines have that problem. They had already encountered it in a number of other vehicles with the issue and all started earlier that year. I am not sure how trying to relay what he said is arm chair quarterbacking but guess to each their own, was just trying to help prevent someone from going through the horrible experience I had to go through.

Perhaps software can somehow make an engine stop producing a sound that triggers the knock sensors, in my case one of four. But they have had a year at least to try and make that fix and if it is out no one is chiming in online about it.

abiazis

Having worked with German companies for close to 20 years......with their culture...they might not be right, but they are never wrong and that is how they handle confrontation....just keep pushing for resolution like us Americans do in our culture!!

moosehead

Whether or not it is willful such as the VW debacle, or a quet neglect perhaps as this issue might be, neither will be a favorable outcome for customers or Porsche.

Coming from an Audi family with 6+ of their vehicles over the years, this is not a typical approach, at least IME. Even for those of us with '16 GTS not experiencing these issues, this aint good.

Hopefully they get it squared away. Thanks for the input on this thread.

Snipe656

It happens to some 2015/2016 S and GTS Cayennes. I never could find an example of where the same engine(be it the bigger or smaller displacement) had it in the other models it is used in. I did see an instance in the Macan that seemed similar but they actually got a message on their display and Porsche resolved them pretty quickly via a software update.