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While trying to diagnose my sluggish and lazily boosting 04 CTT I plugged in my icarsoft POR II and just looked through the datastream from the ECU when "outlet camshaft deviation invalid" jumped out at me. I looked at the row for "camshaft, actual angle bank 2" and it fluctuated from 0, 0.5 rk to -64.0 rk consistently. 


My intake cam deviation has always been around -2.0 *rk (whatever that means) going up to about -3.0 when fully warmed up. The exhaust cam deviation has always been similar. Even previous times the car felt similarly sluggish. If I recall correctly, actual angle has always been around 0 for both banks around idle


I'm not quite familiar enough with OBD2 diagnostic, but I have read about Cayenne timing chain issues and the non key'ed sprockets.. Does anyone have any thoughts? Could be this a bad variocam actuator etc or am i looking a timing chain job frown.gif

Mike

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1 hour ago, Mike Markota said:

While trying to diagnose my sluggish and lazily boosting 04 CTT I plugged in my icarsoft POR II and just looked through the datastream from the ECU when "outlet camshaft deviation invalid" jumped out at me. I looked at the row for "camshaft, actual angle bank 2" and it fluctuated from 0, 0.5 rk to -64.0 rk consistently. 


My intake cam deviation has always been around -2.0 *rk (whatever that means) going up to about -3.0 when fully warmed up. The exhaust cam deviation has always been similar. Even previous times the car felt similarly sluggish. If I recall correctly, actual angle has always been around 0 for both banks around idle


I'm not quite familiar enough with OBD2 diagnostic, but I have read about Cayenne timing chain issues and the non key'ed sprockets.. Does anyone have any thoughts? Could be this a bad variocam actuator etc or am i looking a timing chain job frown.gif

Mike

 

Could be several things.  You may have a cam position sensor on the way out, it could be a problem with the VarioCam system itself on that bank, it could also be a chain issue.  You need to dig deeper...........

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How can exhaust cam deviation be detected with anything? I don't see how this is possible with the available inputs/outputs. The dme has no way to see or calculate exhaust cam position. I think this is a software snafu with your diagnostic equipment. 

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What is interesting to me is that the head bolts, the ex. cam sprocket, and the Intake cam adjuster all use the same exact m12-1.5x140 bolt. The head bolts end up at 22ft lbs with a final torque angle of 90°. The exhaust cam sprocket bolt ends up at 37ft lbs and 90° torque angle. And, the intake sprocket/adjuster bolt ends up at 37ft lbs with a whopping? 135° torque angle. How does the same bolt cover so much ground? These are stretch bolts and Porsche states that the head bolts can be reused. Porsche also states that the cam adjuster/sprocket bolts can be reused if the bolts and diamond washers are only loosened and not completely removed. Am I the only one that thinks there is no difference once it's been torqued and loosened? 

Edited by Mr. Haney
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2 hours ago, Mr. Haney said:

What is interesting to me is that the head bolts, the ex. cam sprocket, and the Intake cam adjuster all use the same exact m12-1.5x140 bolt. The head bolts end up at 22ft lbs with a final torque angle of 90°. The exhaust cam sprocket bolt ends up at 37ft lbs and 90° torque angle. And, the intake sprocket/adjuster bolt ends up at 37ft lbs with a whopping? 135° torque angle. How does the same bolt cover so much ground? These are stretch bolts and Porsche states that the head bolts can be reused. Porsche also states that the cam adjuster/sprocket bolts can be reused if the bolts and diamond washers are only loosened and not completely removed. Am I the only one that thinks there is no difference once it's been torqued and loosened? 

Common sense init!

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