991.2 Carrera - Track Journal!
#106
Rennlist Member
So a little update on my car for those who might be interested
Currently 11 months into my ownership, about 14,100 miles. The car is daily driven (rain, snow, etc)
It has had some issues since the late fall:
1) PDK fault. Was cruising on the highway when suddenly the car refused to go into any of the even gears (2,4,6). It allowed me to continue driving. Turning the car on and off cleared the fault and the car operated normally. Dropped the car off to the dealer, who ran diagnostics and were directed by Porsche Technical to replace the valve body. Car has operated normally (from a transmission standpoint) since.
2) Excessive wind noise from the roof. Diagnosed as sunroof misalignment. Fixed under warranty.
3) Underboosting/"engine control fault". This began a few weeks ago. The first episode was when I was coming home from work. I downshifted in order to pass a car on the highway, and the car suddenly bogged down and threw a CEL. It said "DRIVING PERMITTED", but I noticed the car wasn't allowing full boost pressure. Left the car at the dealer, who diagnosed it as a random computer fault - cleared the code and sent me on my way. 1 week later, the fault occurred again - this time, I was not doing anything but cruising at 80 mph. Again left it at the dealer, who diagnosed under-boosting and suspected wastegate seizure secondary to road salt (???). Not sure if this makes any sense, but they are currently replacing my turbos under warranty (turbo and wastegate are integrated). Also tested the control solenoids and ancillaries. Both times, the car was up to temp (oil temp above 200* F) and I've always used 93 oct. Shell gasoline.
Currently 11 months into my ownership, about 14,100 miles. The car is daily driven (rain, snow, etc)
It has had some issues since the late fall:
1) PDK fault. Was cruising on the highway when suddenly the car refused to go into any of the even gears (2,4,6). It allowed me to continue driving. Turning the car on and off cleared the fault and the car operated normally. Dropped the car off to the dealer, who ran diagnostics and were directed by Porsche Technical to replace the valve body. Car has operated normally (from a transmission standpoint) since.
2) Excessive wind noise from the roof. Diagnosed as sunroof misalignment. Fixed under warranty.
3) Underboosting/"engine control fault". This began a few weeks ago. The first episode was when I was coming home from work. I downshifted in order to pass a car on the highway, and the car suddenly bogged down and threw a CEL. It said "DRIVING PERMITTED", but I noticed the car wasn't allowing full boost pressure. Left the car at the dealer, who diagnosed it as a random computer fault - cleared the code and sent me on my way. 1 week later, the fault occurred again - this time, I was not doing anything but cruising at 80 mph. Again left it at the dealer, who diagnosed under-boosting and suspected wastegate seizure secondary to road salt (???). Not sure if this makes any sense, but they are currently replacing my turbos under warranty (turbo and wastegate are integrated). Also tested the control solenoids and ancillaries. Both times, the car was up to temp (oil temp above 200* F) and I've always used 93 oct. Shell gasoline.
How'd the salt get into there lol. I get surface corrosion...but internal?
Also, you hitting up Autobahn in May?
#107
Drifting
Thread Starter
They claim that the wastegate itself is seized, or seizing intermittently, and that is what the PIWIS seems to be telling them also. It still seems very odd to me that BOTH wastegates would fail simultaneously, which originally made us believe it was a solenoid. However, it seems that all the solenoids checked out...hence the warranty change of both turbos/wastegates. No issues with plumbing, charge piping or otherwise apparently.
Yes I have 15 track days planned on the calendar already - 8 at ACC, maybe 3-4 at RA and a handful at Blackhawk. Will coordinate with you come April!
#108
Rennlist Member
It's a really odd situation. When the car first went in, they actually noted it overboosted once and thought that might've been the cause for the fault overall. However, upon more investigation, it seems that the car is actually underboosting. The techs noted it was difficult to get a road comparison, as its winter and all the comparable cars in inventory are on summer tires.
They claim that the wastegate itself is seized, or seizing intermittently, and that is what the PIWIS seems to be telling them also. It still seems very odd to me that BOTH wastegates would fail simultaneously, which originally made us believe it was a solenoid. However, it seems that all the solenoids checked out...hence the warranty change of both turbos/wastegates. No issues with plumbing, charge piping or otherwise apparently.
Yes I have 15 track days planned on the calendar already - 8 at ACC, maybe 3-4 at RA and a handful at Blackhawk. Will coordinate with you come April!
They claim that the wastegate itself is seized, or seizing intermittently, and that is what the PIWIS seems to be telling them also. It still seems very odd to me that BOTH wastegates would fail simultaneously, which originally made us believe it was a solenoid. However, it seems that all the solenoids checked out...hence the warranty change of both turbos/wastegates. No issues with plumbing, charge piping or otherwise apparently.
Yes I have 15 track days planned on the calendar already - 8 at ACC, maybe 3-4 at RA and a handful at Blackhawk. Will coordinate with you come April!
Hell yea!
That's very odd. I know of a dude who had his turbos replaced due to a similar fault showing up; his is a 4S. He also drives in the snow...not sure if as much as you, but I'll check in with him for details.
#109
Drifting
Thread Starter
Would definitely be helpful, as I am curious about the validity of this whole "wastegate seizing" thing...Yes I daily my car in all conditions and it is never garaged, but its only 11 months into my ownership/14k miles...
#110
Rennlist Member
I'll ask!
You drive it, and that's awesome! Shouldn't cause a failure like this to occur. The waste gate seizing up like that would probably be caused by some sort of ingress that shouldn't really happen. Bad seal would be my guess as a cause for that. Still, Porsche is really good about testing their cars in these conditions. They should have measures in place to keep this from happening.
#111
Drifting
Thread Starter
I'll ask!
You drive it, and that's awesome! Shouldn't cause a failure like this to occur. The waste gate seizing up like that would probably be caused by some sort of ingress that shouldn't really happen. Bad seal would be my guess as a cause for that. Still, Porsche is really good about testing their cars in these conditions. They should have measures in place to keep this from happening.
You drive it, and that's awesome! Shouldn't cause a failure like this to occur. The waste gate seizing up like that would probably be caused by some sort of ingress that shouldn't really happen. Bad seal would be my guess as a cause for that. Still, Porsche is really good about testing their cars in these conditions. They should have measures in place to keep this from happening.
Then again, maybe not
#113
Drifting
Thread Starter
Thanks Pete! The car truly is fabulous. The issues don't bother me too much...car is under warranty and sees admittedly severe duty. It's still been a blast to drive and own thus far!!!
#114
I have a feeling they mean the wastegate actuator - or the actuator wastegate assembly - which is a rod running from the actuator and connected to a lever which in turn is connected to the wastegate. The mechanicals are quite heavy duty. I could see how salt could corrode the point where the lever enters the hot side of the turbo. Keeping in mind the assembly is probably about eight inches off the ground.
#115
I was cleaning my Carrera T on the lift a couple days ago and noticed something that I thought was rather poor design. The rearmost panel inside the rear wheel wells is partly open and does not protect the turbos and actuators from being impacted by road debris. Every stone or clod of dirt that gets picked up by the rear tires is directed at the turbos and ricochets around at which point a LOT of said debris becomes trapped behind the panel and inside the outer rear bodywork. I removed 2 or 3 Lbs of rocks and dirt from each side of my car! And that’s not driving in snow.
The good news is that the rear bumper cover, which includes the external bodywork behind the wheels (where the dirt is being trapped) is plastic, and therefore not prone to corrosion. Nonetheless, I would make the effort to clean this out at least once a year. You will need to remove the rear wheels and a couple of torqx screws.
I can imagine that snow and ice packed into the rear wheel wells might end up damaging some part of the turbos. They are completely unprotected.
The good news is that the rear bumper cover, which includes the external bodywork behind the wheels (where the dirt is being trapped) is plastic, and therefore not prone to corrosion. Nonetheless, I would make the effort to clean this out at least once a year. You will need to remove the rear wheels and a couple of torqx screws.
I can imagine that snow and ice packed into the rear wheel wells might end up damaging some part of the turbos. They are completely unprotected.
#116
Rennlist Member
Hi Jibran. 2750 pampered salt free miles here!
#117
The wastegate arm and valve assembly seizing on internal wastegate turbos is not uncommon. The OEM turbo suppliers actually go through a lot of engineering development to get the right mix of materials for the arm, bushing, and turbine housing to prevent the parts for seizing and also the bushing coming loose from the turbine housing. That all said, I'm not surprised at all that the wastegate arm is seizing. The vast majority of turbos sit in a nice and safe engine bay and the wastegate arm seizing is a failure mode. On the 991 Carrera, the turbos are completely exposed. Get some water, salt, mixed in with exhaust gas coming out of the wastegate bushing (there is an allowed limit of exhaust gas allowed to leak out of the interface between the wastegate bushing and arm), and the wastegate arm can definitely get stuck.
Seems Porsche tried to prevent the issue on later 991.2s by putting a cover over the whole arm and valve assembly.
On the 992, it's really completely covered.
Seems Porsche tried to prevent the issue on later 991.2s by putting a cover over the whole arm and valve assembly.
On the 992, it's really completely covered.
#118
Drifting
Thread Starter
I have a feeling they mean the wastegate actuator - or the actuator wastegate assembly - which is a rod running from the actuator and connected to a lever which in turn is connected to the wastegate. The mechanicals are quite heavy duty. I could see how salt could corrode the point where the lever enters the hot side of the turbo. Keeping in mind the assembly is probably about eight inches off the ground.
The wastegate arm and valve assembly seizing on internal wastegate turbos is not uncommon. The OEM turbo suppliers actually go through a lot of engineering development to get the right mix of materials for the arm, bushing, and turbine housing to prevent the parts for seizing and also the bushing coming loose from the turbine housing. That all said, I'm not surprised at all that the wastegate arm is seizing. The vast majority of turbos sit in a nice and safe engine bay and the wastegate arm seizing is a failure mode. On the 991 Carrera, the turbos are completely exposed. Get some water, salt, mixed in with exhaust gas coming out of the wastegate bushing (there is an allowed limit of exhaust gas allowed to leak out of the interface between the wastegate bushing and arm), and the wastegate arm can definitely get stuck.
Seems Porsche tried to prevent the issue on later 991.2s by putting a cover over the whole arm and valve assembly.
On the 992, it's really completely covered.
Seems Porsche tried to prevent the issue on later 991.2s by putting a cover over the whole arm and valve assembly.
On the 992, it's really completely covered.
This is why I love this forum. Great info, thanks to you both for teaching me something!!! My car has returned with 2 fresh turbos and ancillaries, and is fighting fit once again. Just as well, seeing that the 2019 track season is just around the corner!
#120
Do your new turbos have the cover thing over the wastegate arm and valve assembly of the turbo?