wkearney99

I don't know if I'll be able to make that one. Summer months mean boating season. I'll have to double-check what other family events are scheduled too.

I had a blast thrashing the heck out of the GTS around the cones. The trickiest part is handling the understeer/plow due to the weight. Tricky to, literally, balance the weight transitions. But there was absolutely no sense of body roll or any other looseness. Just MASH the pedals and HANG ON. More finesse would probably have helped, but at ~36 seconds I was still only 3 seconds behind most of the pack averages (in various coupes). Not sure finesse would have made up the gap or not. I didn't care, it was FUN!

I did a PCA Potomac one on the 28th and had less success... and then lost my four remaining runs when they called the event off due to rain. I was bummed, but it was still a fun time.

SCGuy

Ok...posting a couple of updates on this item since I first noticed it almost 1 year ago. I have a 2016 GTS that has been experiencing the "no boost" issue...definitely when cruise control was activated (couldn't maintain speed going up inclines with cruise activated), and also when driving around the city.

I've been going back and forth with the dealer on this item for some time. From what they told me, it was a known issue (experienced by Macans and Cayennes alike), and that Porsche was "aware of the issue and developing a software fix".

The first attempt at a fix was late last year. Apparently, a few vehicles made it to North America with "European fuel" programming (e.g. the vehicle was expecting gas formulated in Europe, but was obviously in North America). A software update was done to fix the issue (I738 / bad region is shown on my invoice). This seemed to make a bit of a difference with regular driving, but didn't touch the cruise control issue.

The second attempt to fix this was made today. Another software fix ("DME update as per TI 2470 / DME update ATI 1704"; hopefully these numbers make sense to someone??).

A quick test on my way home today...and it does seem to be better. A hill on which the vehicle would previously lose speed under cruise control did not trigger the same behaviour. The GTS pretty much kept the speed, and also registered boost while doing so. Tried a couple of other hills, and it again seemed to work much better.

Time will tell...not sure if this will "stick", or if things will adjust back to what they were before. Will keep this forum updated...but at least the initial test results seem promising.

rdboxster

Thanks for the info SCGuy. I am going to talk with service next week. The new to me CGTS was a very early model 2016. Original in service is May 2015. My initial call to service I received the usual response "haven't heard that before".

Rads

Yes, exactly the same problem. My 2016 S with 15,000 miles won't hold speed with cruise control on, and won't give me boost without cruise control on a hill unless I floor it or nearly so. My dealer told me that if the check engine light doesn't come on (it doesn't) there won't be an error code. On my car there's only rarely a problem with the lower gears - especially third - but it is wimpy on the interstates. It much prefers to downshift, say to 5th at 75 mph - than bring in any turbo boost. Very annoying. I couldn't make it do it with the dealership mechanic along for a ride - annoyingly intermittent. Help!

Rads

Thanks, SCGuy. My dealer here in Maine hadn't heard of either the issue or the fix, but he checked it out and got back to me. Apparently Porsche has indeed recognized this as a problem and has developed the fix as you detailed. I am scheduled to have it installed in a couple weeks.

I wonder if the reason this is an intermittent problem indeed has something to do with gas quality and knock detection? Only 91 is available in Maine unless you go to an airport. On a recent long drive I had good days and bad days. I wonder if the good days were after I filled up with 93?

My Cayenne S was manufactured in March 2016, not especially early.

caronsd

Our early-build 2016 GTS went in for it's 40K service today and I provided a complete print-out of this thread showing where I had first posted about my experience with this problem in February.

My Service Advisor called about mid-afternoon - surprisingly, the Tech was able to experience the "no-boost" situation on a test drive. They applied the DME updates listed above. The SA called back later and left a message, telling me that in the Service Bulletin, Porsche states that the problem are "hyper-sensitive knock sensors" that end up pulling boost and timing. We'll see how things go now that "the fix is in". I've got a repeat of the February road trip coming in early August which will be a good test. Fingers crossed!

Snipe656

If it were that simple I'd never had a bad day, all that is sold here is 93. Only time I put 91 in my vehicle was when in the Panhandle since that is the highest octane sold out there.

stiles_s

i just finished a 5 hour road trip east of the mountains in wa. Could reproduce the problem at will after about the 1 hour mark. Takes a slight to moderate uphill grade and pressing the throttle enough to ride on the typically strong low rpm boost wave yet not hard enough to downshift to significantly lower gears. Combo of heat, speed (70-90) and 'load' reproduces easiest. Car just falls on its face. You see a brief spike of boost and then it pulls down to zero. If you shift Dow. A few gears and. Ring the Rpms up it will oblige.

took a bunch of video to share with dealer. Could. E dangerous in passing situations if you are counting on warp speed.

i am going to try some octane booster on the way back for kicks.

stiles_s

I just completed a 500 mile round trip drive. I90 from Seattle to Spokane. The power loss was bad enough that it seriously inspired me to lean on the dealer for a resolution. Turns a car that is pretty quick around town and with leisurely driving into a total dog that can't get out of its own way unless you mash the gas pedal. Lots of video taken.

tried some Techron additive which boosts octane on the way back. Zero effect.

not only at highway soeeds. Will happen just merging into traffic once you ha e heat soaked.

weather was 80s to mid 90s today. The issue is at its worst cruising at 80+ and attempting to accelerate without downshifting. It will eventually give you boost and power if you get the revs high enough bit you need to be driving like a fool. I seriously couldn't keep up with a RAV4 climbing out of the Columbia river gorge without mashing the pedal to the floor.

The whole promise of the turbo was more low end torque.

pretty disappointed. Hope Porsche can figure this out. Those of you who haven't seen this just haven't taken a good length road trip imo.

bweSteve

This is definitely disappointing to hear. Hope Porsche figures this out, cuz it certainly appears plenty of '16 turbo'd Cayenne S's are suffering from this.

I'm still in a {dare I say 'ol skool} 958.1 v8 twin turbo, and I still can't fathom what this must feel like. I've been on thousands of miles / long trips, both towing our 964, and on it's own, and I've never felt anything like this. Even without the Sport button pushed, cruising along in 8th gear, and starting up a long stretched out mountain climb (my daughter just finished 4 yrs in Burlington VT, and our family is in the Adirondacks,.. so yes plenty of good climbs),.. and although the boost gauge definitely jumps around a bit depending on which gear I'm in,... I still get a steady power pull up the mountain whether I want to accelerate or just keep pace.

So sorry to hear this. It does make me pause for a upgrade to a newer CTT.
Do the 17's experience this too?
=Steve

Snipe656

You are describing exactly what I ran into a little over a year ago when taking a road trip from Houston to Littlefield, problem started up hundreds of miles before even getting to the point where 91 octane is sold. Someone earlier in this thread posted that adding high octane "race gas" made it go away for them. I actually bought a case of I think it was called Torco octane booster last summer and was going to try it but never did, by August Porsche finally had admitted they knew about the issue and had no fix for it at the time, so their "fix" was replacing my entire engine.

But given that a software update was put out for this very problem in recent weeks/months then seems really best to take yours to the dealer with a print out of the post a few posts back that has those software numbers. I verified that the numbers posted for that persons 2016 GTS apply to my 2015 S, I just had that software update done since never had 100% confidence them replacing my engine would cause the problem never to come back on my vehicle.

stiles_s

Thanks. Heading to the dealer today. Will keep folks updated.

Update: was able to get some time with the shop foreman today to discuss the problem. He was open and receptive and asked me to leave the car again so they could dig into whether there are any DME updates.

he wasn't interested in seeing the thread from Rennlist

CarGuyNVA

Steve, seems to impact all 958.2 gen twin turbo 3.6 V6s from what I've read (S & GTS).

958.2 CTT (V8) seems fine.

Interesting how the 3.6 V6 twin turbo in the Macan Turbo model doesn't seem to have any reports of this problem (nor does the 3.0 version). Basically the same hardware for the most part with different S/W tuning of course.

This would be maddening! Hopefully Porsche finally gets on top of this issue definitively....not confident that's happened yet based on what I'm reading.

stiles_s

Update after a day at the dealer.

I'm happy to say that my dealer zeroed in on ATI 1704 -- "oversensitive knock detection causes inability for cruise control to hold speed and loss of boost in cayenne s/gts"

Information: "The oversensitive knock detection slows down the timing and cuts turbo boost when no actual knock is present. Updated DME software has been developed to desensitize this knock detection and resolve the corresponding issues."

New software level should be:
S: W09C10BD68SUBFN
GTS: W09C10BD68GUBFN

The only odd part is the shop foreman said I already had that software version, but they reflashed it anyways. I'm crossing my fingers.

Will report back after the next road trip in a couple weeks.

wkearney99

Is there any way in-vehicle to determine the software version? Or is it something that can only be read using PIWIS? Or is there VIN lookup online that'd know what's been loaded?