04 CTT "Outlet camshaft deviation invalid"
04-27-2017, 12:18 PM
#1
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04 CTT "Outlet camshaft deviation invalid"
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
Mike
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
Mike
04-28-2017, 12:48 AM
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On the ICarScan software - there is a measurement for the expected angle and the actual angle. On my '06 955 I found these varied. Never seemed to throw a code or effect performance so I basically ignored this.
The Variocam adjusters are fastened to the end of the camshafts with a single bolt. There is a "diamond washer" between the end of the cam and the Variocam center hub. I assume the diamond washer has a layer of diamond on both surfaces providing friction locking of the Variocam to the camshaft when the bolt is tightened.
I haven't seen any reports on cam chain problems on the V8 engines so if there was a variation I'd be suspicious of the Variocam control solenoid (electrically controlled oil valve) and I've heard there is a wire mesh filter in the circuit that can get plugged up causing sluggish action.
I'd assume your '04 uses the same basic scheme. One thing worth trying - turn PSM off and see how it performs. Whenever mine felt sort of sluggish - a few runs without PSM would bring it back to life. The ECU does learn how you drive and adjust things accordingly. If you're granny driving - it puts it in a granny friendly mode. If you're Juan Fangio driving - it does that too - but can be encouraged to do it quickly by turning PSM off for a while.
The Variocam adjusters are fastened to the end of the camshafts with a single bolt. There is a "diamond washer" between the end of the cam and the Variocam center hub. I assume the diamond washer has a layer of diamond on both surfaces providing friction locking of the Variocam to the camshaft when the bolt is tightened.
I haven't seen any reports on cam chain problems on the V8 engines so if there was a variation I'd be suspicious of the Variocam control solenoid (electrically controlled oil valve) and I've heard there is a wire mesh filter in the circuit that can get plugged up causing sluggish action.
I'd assume your '04 uses the same basic scheme. One thing worth trying - turn PSM off and see how it performs. Whenever mine felt sort of sluggish - a few runs without PSM would bring it back to life. The ECU does learn how you drive and adjust things accordingly. If you're granny driving - it puts it in a granny friendly mode. If you're Juan Fangio driving - it does that too - but can be encouraged to do it quickly by turning PSM off for a while.