Camshaft deviation angle still out of spec after pad replacement
#1
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
My car is a 2000 996 6-speed coupe with approx. 140,000 miles. Since the cam deviation angle on Bank 1 was 7.6 degree (more than the 6 degree limit), I had the pads on the variocam chain tensioner replaced by a Porsche independent mechanic. After the replacement, however, the chain deviation angle went down only a little bit to 6.75 degrees.
What could be the reason for that? Are the camshaft deviation angle sensors identical on both banks? I was thinking of swapping the sensors to verify that the issue is not due to a bad sensor.
Thanks
What could be the reason for that? Are the camshaft deviation angle sensors identical on both banks? I was thinking of swapping the sensors to verify that the issue is not due to a bad sensor.
Thanks
The following users liked this post:
996Driver4528 (08-04-2023)
#4
Nordschleife Master
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Maybe this was done but pull the battery cables and check again. Its been my experience that u should get a 2.5-3.5* change from pads.
Also can u see the "actual values" change about the same amount when u rev the car past the vario engaugment rpm? (I think over 3500)
Also can u see the "actual values" change about the same amount when u rev the car past the vario engaugment rpm? (I think over 3500)
The following users liked this post:
996Driver4528 (08-05-2023)
#5
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
My car is a 2000 996 6-speed coupe with approx. 140,000 miles. Since the cam deviation angle on Bank 1 was 7.6 degree (more than the 6 degree limit), I had the pads on the variocam chain tensioner replaced by a Porsche independent mechanic. After the replacement, however, the chain deviation angle went down only a little bit to 6.75 degrees.
What could be the reason for that? Are the camshaft deviation angle sensors identical on both banks? I was thinking of swapping the sensors to verify that the issue is not due to a bad sensor.
Thanks
What could be the reason for that? Are the camshaft deviation angle sensors identical on both banks? I was thinking of swapping the sensors to verify that the issue is not due to a bad sensor.
Thanks
I checked my reading a couple weeks ago and they are 1.6 / .95 which is solid from when I did the job last year. I'd ask your Indy what he thinks about adjusting the cam sproket to bring it to spec (not too hard, drop the engine a little and remove scavenge pump to access).
Last edited by DSC800; 08-04-2023 at 05:07 PM.
The following users liked this post:
996Driver4528 (08-05-2023)
#6
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I don't think I've seen anyone report more than a ~2* improvement. The pads would need to be pretty much gone to show much more. Chain, sproket, tensioner and guide wear probably account for the other 3+ degrees, this along with not being able to set it back to factory without the fixed tensioner tool (Porsche tool 9599). All this aside I still haven't heard a good explaination as to why it is always bank 1 that is the problem and bank 2 stays well within spec.
I checked my reading a couple weeks ago and they are 1.6 / .95 which is solid from when I did the job last year. I'd ask your Indy what he thinks about adjusting the cam sproket to bring it to spec (not too hard, drop the engine a little and remove scavenge pump to access).
I checked my reading a couple weeks ago and they are 1.6 / .95 which is solid from when I did the job last year. I'd ask your Indy what he thinks about adjusting the cam sproket to bring it to spec (not too hard, drop the engine a little and remove scavenge pump to access).
Also, could you please clarify the following:
- What is the exact purpose of Porsche tool 9599 for my issue? I thought that it is used for removal and installation of the IMS.
- What do you mean by 'adjusting the cam sproket to bring it to spec'? I thought that my Indy already did this when he installed the new pads and the new 'short' chain on the 'Vario'. Do you mean that he should re-check the work done to confirm that everything was done to spec.? Or you talking about a separate operation?
#7
Three Wheelin'
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
My car is a 2000 996 6-speed coupe with approx. 140,000 miles. Since the cam deviation angle on Bank 1 was 7.6 degree (more than the 6 degree limit), I had the pads on the variocam chain tensioner replaced by a Porsche independent mechanic. After the replacement, however, the chain deviation angle went down only a little bit to 6.75 degrees.
What could be the reason for that? Are the camshaft deviation angle sensors identical on both banks? I was thinking of swapping the sensors to verify that the issue is not due to a bad sensor.
Thanks
What could be the reason for that? Are the camshaft deviation angle sensors identical on both banks? I was thinking of swapping the sensors to verify that the issue is not due to a bad sensor.
Thanks
I'd take the car back and ask WTH..
Trending Topics
#8
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
The deviation was measured with the Porsche scanner after the repair and found out of specs. We are all trying to figure out what is going on.
#9
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
First thing I would do is get a new tensioner, pump it up with oil prior to installation then install it. A weak tensioner will allow more cam shaft deviation. IF it has the original tensioners, I would replace all three. I have replace them all on all my cars.
#10
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
When my Indy replaced the 'Vario' pads, he also removed and inspected the bank 1 tensioner (for the long bank 1 chain). He said that it was leaking and needed to be replaced. We did not have a replacement tensioner available, so we left this for another time. Based on your message perhaps this is the cause of much of the deviation angle.
Also, could you please clarify the following:
Also, could you please clarify the following:
- What is the exact purpose of Porsche tool 9599 for my issue? I thought that it is used for removal and installation of the IMS.
- What do you mean by 'adjusting the cam sproket to bring it to spec'? I thought that my Indy already did this when he installed the new pads and the new 'short' chain on the 'Vario'. Do you mean that he should re-check the work done to confirm that everything was done to spec.? Or you talking about a separate operation?
No doubt, a leaking tensioner will cause slack and contribute to greater deviation, so yes, it needs to be replaced. That's easy, do it and let us know, fingers crossed.
- The 9599 tool is the "fixed tensioner" that Porsche used when they built the engine. It should be used when re-timing the engine but it's not made anymore so everyone just uses their oil filed tensioner.
- After you run the engine and check the deviation you can remove the scavenge pump and loosen the four sprocket bolts to advance/retard as necessary. For me this was a separate operation since I would adjust slightly then replace just the scavenge cover (not the whole pump) to run the engine again to re-check the deviation. Repeated this 3 times to achieve <2 degrees. It took a couple hours.
http://986forum.com/forums/performan...rs-timing.html
The following users liked this post:
996Driver4528 (08-05-2023)
#11
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
,
No doubt, a leaking tensioner will cause slack and contribute to greater deviation, so yes, it needs to be replaced. That's easy, do it and let us know, fingers crossed.
http://986forum.com/forums/performan...rs-timing.html
No doubt, a leaking tensioner will cause slack and contribute to greater deviation, so yes, it needs to be replaced. That's easy, do it and let us know, fingers crossed.
- The 9599 tool is the "fixed tensioner" that Porsche used when they built the engine. It should be used when re-timing the engine but it's not made anymore so everyone just uses their oil filed tensioner.
- After you run the engine and check the deviation you can remove the scavenge pump and loosen the four sprocket bolts to advance/retard as necessary. For me this was a separate operation since I would adjust slightly then replace just the scavenge cover (not the whole pump) to run the engine again to re-check the deviation. Repeated this 3 times to achieve <2 degrees. It took a couple hours.
http://986forum.com/forums/performan...rs-timing.html
#12
Three Wheelin'