pete95zhn

So, engine runs like sh*t, stumps at idle and basically over 3k rpm there's no hickups...
Codes thrown:
P0040 Oxy sensors in front of cats changed
P0130 O2 sensor ahead of cat bank 1
P0300/0301/0302/0303 Misfire detection total/Cyl1/2/3

Then from Durametric, engine idling:
Camshaft position 1 deviation 0.14 deg Crk
Camshaft position 2 deviation -4.59 deg Crk
Unfortunately I did not check actual cam values when engine was running.

So, is it the camshaft position sensor or adjustment solenoid at bank 1? I'm in a bit of a hurry, there's this Time Trial I was about to attend next weekend...
I have checked that both cam actuators operate when 12V is fed directly, their wiring is also OK, like wiring to Bank 1 Cam Pos Sensor. As per WSM's test also the LH O2 sensor seems to be OK. LH Valve actuator bracket is OK and the actuaror moves is 12V is fed directly. So it's either the Cam Pos Sensor or something more serious, or is it?
BTW, I just changed to Castrol TWS 10W60, does thicker oil have any effect on VarioCam Plus' operation?

Macster

Are both the solenoid brackets intact? At least one can crack and this plays havoc with the cam timing.

If the brackets are intact then and with the engine behavior reads like a solenoid or actuator (or both) is (are) bad.

A solenoid may not be that expensive with the Turbo engine. (With my Boxster engine it required the camshaft cover be removed and this makes replacing the solenoid rather expensive.)

Then it might worth the time/money to throw a solenoid at the behavior. If this fixes the problem fine. If not then you are probably looking at an actuator.

(I suspect in some cases the solenoid starts acting up and over time this causes the actuator to wear out/fail.)

It didn't happen with my Boxster but the Porsche tech I talked to when I had my Boxster in said it can happen and that is in order to get the O2 sensor readings it expects the DME can adjust the fueling to the point the engine can misfire. Misfires confined to one bank suggest this is happening.

Also, while I think 10w-60 is not the right oil to be using I don't think it is contributing to the behavior. It might prove to be a contributing factor down the road with possibly cam lobe/lifter wear or with problems (wear) with the low/high valve lift hardware so you need to rethink your choice of oil. But I think there is hardware problem, solenoid and/or actuator.

pete95zhn

Move on, move on, there's nothing to see here!


Namely after teasing/clicking all actuators with direct 12V, replacing LH O2 sensor with another (used) one and adding a new gasket between TB and IPD plenum, the engine runs now quite nicely, thank you.
The previous gasket had gone with the wind -or boost...it was still there, but severly damaged and streched and the TB was loose. Reason unknown. Noticed this just by a chance, before starting to drop the engine.
Lambdas in both banks are now normal, as well as camshaft angles. No deviation there anymore.

Macster

That's good news.

RngTrtl

glad that it worked out, but how the hell did it cause those symptoms though? i would have thought that it would throw the code for both banks?