997.2 Carrera misfire = complete lifter and camshaft replacement??
#17
please keep us posted here! i have the same now; misfire , always on #2, i changed spark plugs, coils, injector nozzle, tappets on no.2, changed variocam and valve lifter, checked valve springs, leak tested, compression checked...
All is GOOD, fault persists.
Need ideas pls! :-:
All is GOOD, fault persists.
Need ideas pls! :-:
#18
please keep us posted here! i have the same now; misfire , always on #2, i changed spark plugs, coils, injector nozzle, tappets on no.2, changed variocam and valve lifter, checked valve springs, leak tested, compression checked...
All is GOOD, fault persists.
Need ideas pls! :-:
All is GOOD, fault persists.
Need ideas pls! :-:
#19
Wow this such a great community. I almost never get replies this thorough as a newb in most other forums.
to answer some of the questions... under 30k... the car tends to run notably rough right from startup. Never stalls but there is a notable "wop-wop-wop" to the idle and when cold you can even faintly see that pattern of that running in the exhaust puffs of the evaporating condensation. Once you take off it is semi rough until 45 mph or so at which point it really starts bucking against you. The PDK seems to really get confused by all this.
And again, this was the smoothest running car on the planet a couple of weeks ago. It was fine when we went to dinner, and did this on the way home. The only environmental change was that it was right after the last snap of VERY cold weather in south Texas. Perhaps a day or so later.
I agree about the variocam. That sounded like a promising lead until my old mechanic where I used to live said that would not likely be throwing codes for one cylinder but rather a bank for that side.
to answer some of the questions... under 30k... the car tends to run notably rough right from startup. Never stalls but there is a notable "wop-wop-wop" to the idle and when cold you can even faintly see that pattern of that running in the exhaust puffs of the evaporating condensation. Once you take off it is semi rough until 45 mph or so at which point it really starts bucking against you. The PDK seems to really get confused by all this.
And again, this was the smoothest running car on the planet a couple of weeks ago. It was fine when we went to dinner, and did this on the way home. The only environmental change was that it was right after the last snap of VERY cold weather in south Texas. Perhaps a day or so later.
I agree about the variocam. That sounded like a promising lead until my old mechanic where I used to live said that would not likely be throwing codes for one cylinder but rather a bank for that side.
The following users liked this post:
kepro74 (08-21-2021)
#20
topping off gas might be the issue
I had similar issues, and found that I was overfilling the gas tank. I was topping off. When I stopped doing that, the problem disappeared. I stop fueling when the automatic sensor stops the pump. Stalling/stuttering issue absolutely gone since I used this method.
-2011 Carrera with 95K miles.
-2011 Carrera with 95K miles.
The following 2 users liked this post by spaceflowers:
groovzilla (01-05-2022),
herbg (07-10-2023)
#21
Burning Brakes
Resurrecting this old post. After coming off the highway got a rough idle with associated check engine light. Pulled the same codes except the misfire and valve solenoid fault were for cylinder #1. Cleared the codes. Got a smooth startup but experienced the same symptoms and same codes after a highway jaunt. Indy shop recommended replacement of Camshaft and Valve Lifters on that bank. $3,200. 90k miles on a 2011 4S
Last edited by Hula; 07-10-2023 at 08:44 PM.
#22
Burning Brakes
Correcting the previous post to add to the knowledge base. I didn't need a new camshaft but the camshaft does need to be removed to replace the lifters. Also didn't need to replace all the lifters on the bank. Just the lifters on the misfiring cylinder. My mechanic blamed a pin in the internals of the lifter itself. He's seen this a couple of times before. Replacing the lifters solves the problem but labor is intensive. It's proper surgery.
Last edited by Hula; 08-04-2023 at 04:09 PM.
#23
Burning Brakes
Well my third post on this issue. Same original error popped up soon after the lifter replacement. My mechanic hooked up some diagnostics and let it idle for a few hours. He discovered an occasional short duration oil pressure drop off. The faulty part turned out to not be the sensor. Not the lifter. It was the oil pump regulating valve. Sounds scary. It's been three months and a few thousand miles since the valve replacement and I'm declaring victory.
#24
Rennlist Member
Well my third post on this issue. Same original error popped up soon after the lifter replacement. My mechanic hooked up some diagnostics and let it idle for a few hours. He discovered an occasional short duration oil pressure drop off. The faulty part turned out to not be the sensor. Not the lifter. It was the oil pump regulating valve. Sounds scary. It's been three months and a few thousand miles since the valve replacement and I'm declaring victory.
Keep this thread updated please.
#26
Rennlist Member
Well my third post on this issue. Same original error popped up soon after the lifter replacement. My mechanic hooked up some diagnostics and let it idle for a few hours. He discovered an occasional short duration oil pressure drop off. The faulty part turned out to not be the sensor. Not the lifter. It was the oil pump regulating valve. Sounds scary. It's been three months and a few thousand miles since the valve replacement and I'm declaring victory.
#27
Rennlist Member
Well my third post on this issue. Same original error popped up soon after the lifter replacement. My mechanic hooked up some diagnostics and let it idle for a few hours. He discovered an occasional short duration oil pressure drop off. The faulty part turned out to not be the sensor. Not the lifter. It was the oil pump regulating valve. Sounds scary. It's been three months and a few thousand miles since the valve replacement and I'm declaring victory.
#28
Burning Brakes
Yep. Symptoms started at idle, soon after a start, with a "Oil pressure monitoring defective" warning on the dash with the indicated oil pressure dropping to zero. No change in engine idle. Lasted about 10 seconds before the warning self extinguished and the oil pressure needle jumped to a normal reading. It happened again a few weeks later so I figured a sensor going bad. Not a lot of data on this failure mode and difficult to reproduce but my mechanic agreed and replaced the oil pressure sensor. About 200 miles after the repair, coming off the highway and sitting at a light, I got the misfire and fault code. A restart solved the misfire but back to the shop. Code and misfire indicated bad lifter. After the new lifter, coming off the highway and sitting at idle again, the "Oil pressure monitoring defective" warning returned.
My mechanic is a long time Porsche tech and he reached out to others in the community. I don't like the parts cannon approach but he found the right info and performed right test to isolate it to the valve. $1,600. About half of that labor. I wasted a lot of time and money chasing this one down. I considered a Toyota at my lowest point but it's back to running strong now.
My mechanic is a long time Porsche tech and he reached out to others in the community. I don't like the parts cannon approach but he found the right info and performed right test to isolate it to the valve. $1,600. About half of that labor. I wasted a lot of time and money chasing this one down. I considered a Toyota at my lowest point but it's back to running strong now.
Last edited by Hula; 11-11-2023 at 02:11 PM.
The following users liked this post:
BLU997 (11-12-2023)