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My first post here. I'm struggling with a P0018 code (camshaft to crankshaft correlation error) on a 2006 Porsche Cayman S.
P0018 code has been there since first crank, and now I'm also seeing P0430 error (Catalyst System Efficiency Below Threshold -Bank 2).
Motor now has 2000 miles on it, still havent figured this out, but car runs fine as a daily driver.
Symptoms:
NONE! The car starts fine, idles fine. At all engine rpm ranges, feels good all throttle positions and loads.
History:
* I rebuilt the motor after getting special engine build training from Jake Raby of Flat 6 Innovation.
The motor is from a 2008 Porsche 911 - 3.8L. I transplanted it into a 2006 Cayman S (comes with a 3.4L). They both share the same base software algorithms, just different tuning.
I did all the cam timing using factory tools/fitures to ensure accuracy. I used Softronics software reflash specific for this engine swap. The car started on first crank with fresh built motor, but P0018 has been there since first crank on new motor. Prior to engine swap, there were no error codes on the stock motor.
Specs related to error code P0018 and P0430:
- Vehicle is equipped with variable valve lift and timing (VarioCam Plus)
Scan Tools: Using Durametric OBDII scan tool to read codes, and also test/command variable valve lift & timing solenoids
Current Situation:
1. I can command the valve lift solenoid on each back when the vehicle is idling, and I know it works correctly because it activates and the car stalls.
Camshaft deviation (from optimal) on bank 1 is about 2 degrees, and about 6 degrees on Bank 2 (where the P0018 error is). I was told my porsche factory techs that a combined 12 degrees of deviation is the limit to which you need to redo timing.
I cannot see any change in camshaft variable timing/phasing target when adding load to the engine (at idle, and at speed, with varying throttle). No change in camshaft target at any condition (even after I clear the P0018 fault codes)
2. I removed all lift and timing solenoids from the engine and bench tested with basic 12v battery to manually actuate each solenoid. They all work correctly. (All actuate the same amount of travel, and clear of any dirt or debris)
3. I swapped the timing solenoids from bank 1 to bank 2 to check if the error followed the solenoid - negative. Error remained P0018.
4. I swapped the LIFT solenoids from bank 1 to bank 2 to check if the error followed the solenoids - negative. Error remained P0018.
5. I swapped camshaft position sensors from bank 1 to bank 2 to see if the error followed a camshaft position sensor - negative. Error remained P0018.
PROBLEM: I try to manually command the timing solenoids with Durametric tool to activate on either bank (even after clearing the fault codes) - but nothing happens. (the computer just says - "sending command"...but nothing happens - i dont hear anything actuate)
I cannot wrap my head around how to check electrical harness for these solenoids. (I have no idea what a good lift solenoid signal is supposed to look like, @ idle, @ activation, etc)
The solenoids have 2 wires.
Any ideas on how to proceed? Your input would be much appreciated.
You state to have changed cmp sensors between banks. Did you also scope the signals just to verify the reluctor integrity?
Is it possible to take an in cylinder pressure reading of one cylinder of each bank in order to compare them with regards to valve timing events, vacuum pull etc?
An expert is someone who knows each time more on each time less, until he finally knows absolutely everything about absolutely nothing.
I dont have much experience with scoping signals, and I dont have a scope either. I dont even have access to a database showing correct waveforms. Kinda stuck on that one.
I have seen a video that uses starter cranking amps( with fuel pump fuse removed) to determine lower compression on the bank with the P0018 error (by seeing change in peak amps between the good bank and bad bank due to bad timing), correlated with one of the cylinder coils with inductive loop sensor and firing order reference to get a reading on cylinders on bank1 and bank2.
I also read that a stretched chain can be the issue as well, but I find that to be highly low probability to stretch a chain? But honestly I didnt even know to check that when i put the chains on while building the motor. I assumed they were still good (they looked good).
I am also going to contact softronics and ask for the original 987 Cayman S software and see just for sanity check if the error is still there.
I just find it odd that I've NEVER seen a target signal for cam phasing angle since the engine swap (even when driving under varying loads). Both banks target phasing have always been stuck at zero, and so is the actual phasing signal, zero.
I saw another video of a P0018 code on a Kia sorento and at least it still showed the cam phasing targets, even with the P0018 active.
Maybe porsche wrote a failsafe algorithm to deactivate the phasing logic to avoid damage? No idea.
