05 CTT Rough Acceleration/Stuttering
12-27-2008, 07:59 PM
#17
The idea of "fouled" plugs is a bit of a red herring given the very high combustion temperatures and precision of fuel injection in modern street engines. I'm not confident to leave these so-called "long life platinum" plus in a car for 50K or 100K, but even when my Cayenne was running like a 4.5 cylinder (instead of 4.5 litre) engine, the dealer fixed the problem by a programming update and the plugs didn't make any difference. I could labor the "scientific method" flaws in this case, but I imagine everyone gets the idea.
For context, I have an '05 with the factory Power Kit -- arguably one of the most highly strung engines Porsche has ever put in a street car. The latest "Turbo S" maps (or whatever other programming changes) cured the hiccups. At first, they apparently replaced all the plugs, and some of the coil packs (by eyeball) and gave the car back to me in a better -- but still unhappy -- condition. Why give back a car that's not 100%? Anyway, on the second visit (and another day or two in a surprisingly fun V6 DI) the full force of the Power Kit Turbo was restored and I got to relive my first days of enjoying driving three tons of arrogance and superiority
heft. Bottom line: '05 cars had programming that didn't accommodate 91 RON "California water" fuel and the notorious OEM quality of the coil packs make for a mandatory visit to the dealer for the update.
For context, I have an '05 with the factory Power Kit -- arguably one of the most highly strung engines Porsche has ever put in a street car. The latest "Turbo S" maps (or whatever other programming changes) cured the hiccups. At first, they apparently replaced all the plugs, and some of the coil packs (by eyeball) and gave the car back to me in a better -- but still unhappy -- condition. Why give back a car that's not 100%? Anyway, on the second visit (and another day or two in a surprisingly fun V6 DI) the full force of the Power Kit Turbo was restored and I got to relive my first days of enjoying driving three tons of arrogance and superiority
heft. Bottom line: '05 cars had programming that didn't accommodate 91 RON "California water" fuel and the notorious OEM quality of the coil packs make for a mandatory visit to the dealer for the update.
12-27-2008, 08:35 PM
#18
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12-27-2008, 08:57 PM
#19
Differ away, I'm curious to hear your nominations.
Understand what I mean by "highly strung" (and I'm sure I should have chosen a more appropriate expression) and "street car" and I'm curious to have anyone nominate a street car with and engine to compare. Yes, you could argue an early Carrera GT (you know, "the other Carrera GT") though I don't think of it as a street car per se and I think it's useless to give the current Carrera GT the title in all categories. And by "highly strung" I mean the Cayenne Power Kit Turbo is dialed into a fine tolerance while the C-GT could produce a reliable 1000 HP before I'd call it highly strung. Of course, the 8400 rpm GT3 engine deserves full respect -- and I find it astonishing that Porsche can produce a production line engine with full warranty to GT3 specs, which would have been an extraordinary achievement in a hand built race engine with zero warranty and a lifespan measured in hours -- but in terms of what Porsche has done with street cars, the Cayenne Power Kit Turbo and arguably the current direct injection Turbo S are pretty respectable engines.
Understand what I mean by "highly strung" (and I'm sure I should have chosen a more appropriate expression) and "street car" and I'm curious to have anyone nominate a street car with and engine to compare. Yes, you could argue an early Carrera GT (you know, "the other Carrera GT") though I don't think of it as a street car per se and I think it's useless to give the current Carrera GT the title in all categories. And by "highly strung" I mean the Cayenne Power Kit Turbo is dialed into a fine tolerance while the C-GT could produce a reliable 1000 HP before I'd call it highly strung. Of course, the 8400 rpm GT3 engine deserves full respect -- and I find it astonishing that Porsche can produce a production line engine with full warranty to GT3 specs, which would have been an extraordinary achievement in a hand built race engine with zero warranty and a lifespan measured in hours -- but in terms of what Porsche has done with street cars, the Cayenne Power Kit Turbo and arguably the current direct injection Turbo S are pretty respectable engines.
12-27-2008, 09:44 PM
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I should note that all of my coil packs were cracked and my plugs were not fouled, just old. The PO had never changed the plugs. I thought that the car had 50k miles however it has more like 59K. 59k is a bit long on a CTT.
I was told that I was to change the oil every 15k since the oil is synthetic (yes, I know...bad advice...). There has been about 10k since the previous oil change. When the oil was changed (not by me) the oil level was between min and max on the dipstick. When I had to add oil, I had to add 1 3/4 quarts to get the level to max. I estimate that it only needed about 1 quart to get it where it originally started. I do not think that 1 qt in 10k miles is a concerning amount of oil- especially for a high performance engine.
I was told that I was to change the oil every 15k since the oil is synthetic (yes, I know...bad advice...). There has been about 10k since the previous oil change. When the oil was changed (not by me) the oil level was between min and max on the dipstick. When I had to add oil, I had to add 1 3/4 quarts to get the level to max. I estimate that it only needed about 1 quart to get it where it originally started. I do not think that 1 qt in 10k miles is a concerning amount of oil- especially for a high performance engine.
12-27-2008, 10:13 PM
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12-27-2008, 10:39 PM
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12-27-2008, 10:53 PM
#27
It's like talking with my -- philosopher -- brother. He's the only guy I know who, when first hearing of the "what 'is' is" defense, rubbed his beard and stared into the distance to ruminate on the concept (while the rest of us rediscovered the word "guffaw.")
Annnnnyway. I meant "in it's day" because today there are some impressive upgrades to the humble 993 Turbo engine that take it to the limits of its factory internals (let's call it 520 hp and 520 lb ft for upper limits on factory connecting rods) and, for all intents, that decade old car is still a fighting contender with any of the current crop. I guess I wear my 993 heart on my sleeve, but I think Mr Porsche is yet to better that 911. (I can hear the Cayenne forum regulars mumbling advice for me to take it where it belongs and seasons' greetings ... : )
Annnnnyway. I meant "in it's day" because today there are some impressive upgrades to the humble 993 Turbo engine that take it to the limits of its factory internals (let's call it 520 hp and 520 lb ft for upper limits on factory connecting rods) and, for all intents, that decade old car is still a fighting contender with any of the current crop. I guess I wear my 993 heart on my sleeve, but I think Mr Porsche is yet to better that 911. (I can hear the Cayenne forum regulars mumbling advice for me to take it where it belongs and seasons' greetings ... : )
12-28-2008, 04:00 PM
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I should note that all of my coil packs were cracked and my plugs were not fouled, just old. The PO had never changed the plugs. I thought that the car had 50k miles however it has more like 59K. 59k is a bit long on a CTT.
I was told that I was to change the oil every 15k since the oil is synthetic (yes, I know...bad advice...). There has been about 10k since the previous oil change. When the oil was changed (not by me) the oil level was between min and max on the dipstick. When I had to add oil, I had to add 1 3/4 quarts to get the level to max. I estimate that it only needed about 1 quart to get it where it originally started. I do not think that 1 qt in 10k miles is a concerning amount of oil- especially for a high performance engine.
I was told that I was to change the oil every 15k since the oil is synthetic (yes, I know...bad advice...). There has been about 10k since the previous oil change. When the oil was changed (not by me) the oil level was between min and max on the dipstick. When I had to add oil, I had to add 1 3/4 quarts to get the level to max. I estimate that it only needed about 1 quart to get it where it originally started. I do not think that 1 qt in 10k miles is a concerning amount of oil- especially for a high performance engine.
ltc can start digging a hole for mine with a toothpick...
Last edited by cayenne-kimo; 12-29-2008 at 12:40 AM. Reason: correction
12-28-2008, 07:11 PM
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I was looking through the paperwork. Everything for the 40k service was done except the plugs. I am not sure why. I am guessing that the place that did the service (not a porsche dealer) read the service guide for the cayenne s. I believe that the S's get new plugs at 60k. Not sure, just my guess.