"Spun" Camshaft
#166
It takes a sharper mind than mine to answer that one. I'll look for my deviation and post it for you though.
Mine was based on taking it apart to inspect. I knew I was going to pin both when it happened regardless of whose tab it was on, so it was an easy decision for me.
Edit: found mine:
Mine was based on taking it apart to inspect. I knew I was going to pin both when it happened regardless of whose tab it was on, so it was an easy decision for me.
Edit: found mine:
Is that image of camshaft angle reading when it was bad, or normal?
Just curious for clarity...
BTW...How is your car running now after all your work? I imagine pretty well.
Thanks!
DC
#167
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As for how my car runs, let me put it this way. I'm on my 5th Mezger motored 911 (3 996tt's, 1 993tt, and 1 997tt) all with similar mileage. This is by far the smoothest running of them all... and it's not even close.
#168
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Anything less than 6 degrees (either plus or minus) of cam deviation per bank is considered "in spec" by Porsche, I believe. Not sure what happens when it gets outside of that, maybe that's when the CEL gets tripped..
Not sure about the cam angle values..
Cincy's numbers under 1 degree for deviations on both banks would be considered quite good, I think..
Not sure about the cam angle values..
Cincy's numbers under 1 degree for deviations on both banks would be considered quite good, I think..
#169
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Getting Scott's camshaft deviation numbers is/are very good.
There is a inside story about how Porsche has removed the chain tensioner "step" in the repair procedure. Please note: anyone that has this repair done, please ask the tech to use the 964 chain tensioner when cam timing your engine. Scott paid some extra labor to get it done>the results speak for themselves.
There is a inside story about how Porsche has removed the chain tensioner "step" in the repair procedure. Please note: anyone that has this repair done, please ask the tech to use the 964 chain tensioner when cam timing your engine. Scott paid some extra labor to get it done>the results speak for themselves.
#170
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Getting Scott's camshaft deviation numbers is/are very good.
There is a inside story about how Porsche has removed the chain tensioner "step" in the repair procedure. Please note: anyone that has this repair done, please ask the tech to use the 964 chain tensioner when cam timing your engine. Scott paid some extra labor to get it done>the results speak for themselves.
There is a inside story about how Porsche has removed the chain tensioner "step" in the repair procedure. Please note: anyone that has this repair done, please ask the tech to use the 964 chain tensioner when cam timing your engine. Scott paid some extra labor to get it done>the results speak for themselves.
As far as "new" vs "old," the manuals state different methods to time them. The 997 manual's version doesn't use some special tools that the 964/993/996's do, so there seems to be some confusion on it. Mine was originally timed as a 997, but was re-timed as a 964.
My tech after talking to us about it agreed that he would never time another 997 the new way again...
#171
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My car is .3 to .4 across the board. Engine guy said its the most dialed in he's been so far. I should note he was this accurate both times he put mine back together
#173
This after you have checked that the lobes are all at the same separation. I can tell you there is often a big difference between the trigger wheel position to the lobes and the lobe separations on different camshafts. Add in the fact that most engines run zero lash on the follower (not by design) the cam geometry is off, which affects the performance.
I guess it comes down to how close do you want it.
#174
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#175
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It takes a sharper mind than mine to answer that one. I'll look for my deviation and post it for you though.
Mine was based on taking it apart to inspect. I knew I was going to pin both when it happened regardless of whose tab it was on, so it was an easy decision for me.
Edit: found mine:
Mine was based on taking it apart to inspect. I knew I was going to pin both when it happened regardless of whose tab it was on, so it was an easy decision for me.
Edit: found mine:
#176
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I could be wrong, but I don't think these readings will show if you have an issue like the one described in this thread. They can do the reading from the PIWIS, but I don't think it's a smoking gun. However, it is something to make sure you know the readings, because it helps to know how much the cams are fighting each other (creating loss) in your motor.
#177
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Anything less than 6 degrees (either plus or minus) of cam deviation per bank is considered "in spec" by Porsche, I believe. Not sure what happens when it gets outside of that, maybe that's when the CEL gets tripped..
Not sure about the cam angle values..
Cincy's numbers under 1 degree for deviations on both banks would be considered quite good, I think..
Not sure about the cam angle values..
Cincy's numbers under 1 degree for deviations on both banks would be considered quite good, I think..
I could be wrong, but I don't think these readings will show if you have an issue like the one described in this thread. They can do the reading from the PIWIS, but I don't think it's a smoking gun. However, it is something to make sure you know the readings, because it helps to know how much the cams are fighting each other (creating loss) in your motor.
#178
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hmm i'll have to address this with them if it comes up. I finally heard from the dealer and they are doing the same thing they did last time, swapping cam sensors to see if the sensor or cam is bad. $780 worth of work lol. I have no idea where the cam sensors, but i'm surprised it's 5 hours worth of work. Seems like a lot. They have to put at least 60 miles on the car too.... so I guess the foreman is going home with my car tonight, he better be nice.
#179
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It's just difficult to get them to diagnose the problem as definitively being the camshaft without going in and pulling it. So they are trying to see if they can fix it without the cam being the problem. I told them i just don't want them doing the same thing twice and having the issue after another 10k miles. They should say to the insurance company that this is the second time and that the cam needs to be replaced. That's why I have coverage and it should get fixed properly. They stated it could be the oil since it's due for a change...
#180
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http://www.fidelitywarrantyservices....cle-protection