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No experience replacing one, but when the VarioCam solenoid/actuator in my Boxster acted up the engine's idle became rough and took to rising and falling.
There was no CEL. I checked and there was a pending code that pointed to the solenoid/actuator.
I turned off the engine and upon restart it was well behaved. I drove home without any drama -- but still sitting on the edge of my chair, so to speak -- and the next day got the car in to the dealer. The tech ended up replacing both the solenoid and actuator.
Why do you want to replace the VarioCam actuator? What is the engine doing that makes you think anything with the VarioCam (Plus) system needs replacing?
Absent any clear signs of trouble in this area, absent any active or pending error codes, with no more than just a suspicion of a problem, I guess one could test the VarioCam solenoid/actuator operation using a Porsche diagnostics computer that would exercise the solenoid/actuator for each bank and then confirm the desired timing change occurred by monitoring the cam timing from the cam shaft position sensors.
Why do you want to replace the VarioCam actuator? What is the engine doing that makes you think anything with the VarioCam (Plus) system needs replacing?
Fair question and to be totally honest, my suspicions have to do with both my active imagination and a desire to get rid of that 2800 rpm hesitation I have.
To refresh memories, this hesitation appears in in random cars and supposedly even occurs in the 991 series. My dealer experienced it in my car during a test drive although it appeared very benign to him as I was on flat ground and on bumpy roads. It is most pronounced when cold and under mild load such as going up a hill under light acceleration.
His comment "While this is not a known issue with a published repair I believe I am familiar with your concern. I believe what you are experiencing i a mix of the vario-cam system actuating in conjunction with the tuning flap in the intake manifold. While the exact RPM varies dependent upon engine load and other factors, the variable lift begins to change from low lift to high lift around that period of time you describe. Also, the intake manifold tuning flap closes at 2600 rpm to help increase mid-range torque on these engines. It is very possible that you are noticing these events which are not a problem so much as a part of the normal operation of the engine management system."
I fully believe, as various Porsche tech suspect, it is the variocam transition. My active imagination is concluding (fantasizing) that the actuator or the valve is lazy and not moving when the computer is telling it to.
I will be changing my own spark plugs in a few months and figured I could swap them out at that time (1 per bank, about $150 ea) - The actuator is located next to the plugs. For DIY, they are stupidly easy to replace once in there. The valve itself looks impossible to get to. So I've been fishing for some information about the actuator. What I want to know is for those that changed them, what were the symptoms. At this point in time, those that did had a code (but no lamp).
JFP at RennTech suggests I use my Durametric and track cam deviation values. I can do this... record the values... but have no clue what the heck to look for. He too said the computer should throw a code but my car, like others who are experiencing this, are not throwing any codes at all.
If I had to make a decision now, I would not change them because I have no evidence to support they are a problem.
I am a dope.... I forgot to buy them when I did my plugs at 80K. I could kick myself.
The hesitation is still with me, still annoying, still the worst thing technically about this car. I do have some new information...... With my windows down and sunroof open, I can hear the transition and I am getting a faint pshtttt..... almost like a turbo waste gate. I noticed this some time after I put on the Sharkwerks cross pipe but this just may have been a coincidence with my perception and timing.
Another project that my active imagination is cooking up, is to pull the intake apart and find that darn flap..... maybe it is just sticking somewhat..... I dunno.
This is annoying and those that have this hesitation hate it. Is that because we have it and others don't or that we are just more picky about how a $110K car should perform?
If you find out ANYTHING about his issue, please post or PM me.
Peace
Bruce in Philly
Last edited by Bruce In Philly; 09-27-2016 at 10:36 AM.
I noticed the same noise when I installed my crosspipe on was well. Is your car tuned? I have experienced this issue with both an EVOMS and a stock tune.
I am getting ready to do the plugs, so I might replace the actuators. I need to make sure this isnt something where the timing needs to be locked into place and the oil drained out of the car before I get into an issue while replacing them.
I read another thread where they say to stab the gas pedal quickly when the car is warming up, and it helps with the issue. Did you try this action, and did it work for you at all?
Oh, and I agree with your sentiments regarding the worst thing mechanical about the car. I have owned BMWs the rest of my adult life (excluding the non-fun DDs), and this hesitation, coupled with my BMW experience, makes me worry my motor is going to break in half every time it happens.
FWIW, I noticed this same issue on 2 other cars when I was looking for a 997.2. They were both 2009s. Not sure if its a coincidence or not. Maybe its worth going to the dealer and driving whatever 997.2 they have on the lot?
[EDIT] Oh, and since we both have durametrics, if you think of something you want to log and compare, I am game. I need to get this hesitation taken care of before it forces me into a 1994 GMC astro van
This dialog is good....... I feel better that my car is not uniquely broken in any way.
My car is not tuned... only performance mod I did was this cross pipe. I don't have a manual on changing the actuators. Maybe a ping over a RennTech... I will drop them an email this evening as I am a paying member there.
Regarding other 2009s... yep, and those that have it appear to be pretty angry.
Regarding worry..... I put 75K on this car with now 102K miles and it hasn't blown up yet. Performance never changed.... this car is very consistent.
I would be happy to collect Durametric data and compare.... I just don;t know what to collect. Let's communicate via email or phone this weekend (maybe this weekend is bad...).
My indy made some suggestions on what to measure.... he held the monthly pca meeting at his shop and I asked him about this... he didn't know but he did suggest some things to measure with live values (he uses Durametric for his Porsche shop)
Guys;
I'd be happy to add another source of durametric data. (2009 C2 PDK).
I feel the slight change around 2800 RPM also. I'm not sure I'd describe it as a hesitation though. It is difficult to describe as it is not something that has bothered me.
It is more of a slight transition where it seems above 2800 something has changed and there is much more instantaneous torque available.
Let me know what parameters you want to measure and I'd be happy to contribute.
Apparently this is also a 991 issue..... I am starting to believe this is a feature of the car but I just don't know why more aren't complaining about this very obvious and annoying performance issue.
I don't feel a hesitation but I can often times hear the transition if I'm at a steady-state throttle around the 2800 rpm range and then accelerate. It makes a sort of quick clickity-clack sound. It's always done that the 4 years I've owned the car. Don't know if it's considered normal but that's just what my engine does.
I have replaced these solenoids in the Cayenne GTS 4.8L. Very straightforward R/R as it seems. I wonder if there is a way to monitor the duty cycle on them with durametric.
I have replaced these solenoids in the Cayenne GTS 4.8L. Very straightforward R/R as it seems. I wonder if there is a way to monitor the duty cycle on them with durametric.
Why did you replace them? Symptoms? Throw a code?
We are looking into the capability of Durametric this week and plan on gathering some live data.
03-07-2015, 08:44 AM
Anyone Replace Variocam Actuator?
