Variocam Actuator Testing.
 

Is there any way to bench test a variocam actuator? i would like to test mine before spending the big bucks on a new one.

The easies, and perhaps best method, to test the VarioCam units is in the car with either the Durametric software or a PIWIS system. One click of the mouse and you will know.

Yes, but unfortunately there are other factors that can cause it not to work. The other option would be to test the circuit. Can that be tested with a noid light?

I just put voltage directly to the actuator while it was running and there was no change. I tested the solenoid when I had it out. I just find it hard to believe that two diffent actuators would give me the same cam deviation results. Especially since the pads were worn off one and the intake cam had skipped a tooth. I have access to a third one and may have to bite the bullet and try that.

We test them in place with a Porsche diagnostic tool; takes about 30 seconds to determine if and what is bad.

Really, my friend that is a master Porsche tech says the PIWIS wont even do that. What do you use?

I rounded up a third actuator. When I took it apart I noticed the solenoid plunger was in upside down. Now to put it all back together and try again.

Then your friend needs to go back to school; both the PIWIS and the Durametric system can activate the VarioCam units, one at a time so you can see the unit's response in the real time cam angle data. You would also note a significant change is the vehicle's idle when the cam moves as well.

But that wont tell you what the problem is. Its only a clue as to where to look.

Looks like I got it nailed this time. Check engine light out and running smooth.

A clue that tells you your variocam actuator is bad...wasn't that what you were trying to determine?

Glad you got it figured out.

It could have been the actuator, the solenoid, the wiring, timing, ramps, or the DME. I just dont like guessing with expensive parts if I dont have to.

except if the Variocam has been incorrectly reassembled and the vital solenoid plunger is upside down ! Same result if there was a wiring fault.
Seems JFP was correct.
If the Durametric does not operate the Variocam ,it probably needs to be repaired/replaced.

Straying a bit off topic (It's okay since the crisis has passed), here's a cool thread about the failure and dissection of a very similar unit from an Audi A8:

quattroworld.com Forums: Failed 40V cam adjuster dissected...disappointingly non-rebuildable >>>

I'm guessing that ours have a green plastic O-ring where these have the black one.

Interesting that the solenoid plunger was upside down. There certainly isn't a Durametric test for that. But it seems you had other severe problems - timing chain skipped a tooth and excessive pad wear. Cumulatively that is a lot of issues.!