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2009 C2S - 2700 RPM drop/thump

Bruce in Philly
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Bruce in Philly Member

Bruce in Philly

Posted
Posted

2009 C2S coupe

I am experiencing an odd engine behavior around 2700-2900 RMP when accelerating under mild load.... I get a quick miss/drop in power / thumpshake from the engine. I posted on another forum and it appears to be definitely experienced by some but not all. Some, like me, believe it is the variocam transition.

Any insights into this?

I spoke with my dealer tech and he didn't know nor had anyone complained. He said the variocam is actuated at 2200 RPM. Another poster spoke with his dealer tech, went for a ride, and the tech said "definitly variocam... some cars have it, others don't (drop)". My indy said it is definitely the variocam and the turbos always did this, the turbos were the first car to get the variocam. True???

I purchased the car, new to me a few months ago and it always did this, I now have 37K miles on it.

Of course I am paranoid that something is amiss (yes, pun intended).

Thanx

Bruce in Philly

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JFP in PA Member

JFP in PA

Posted
  • Moderators
Posted

2009 C2S coupe

I am experiencing an odd engine behavior around 2700-2900 RMP when accelerating under mild load.... I get a quick miss/drop in power / thumpshake from the engine. I posted on another forum and it appears to be definitely experienced by some but not all. Some, like me, believe it is the variocam transition.

Any insights into this?

I spoke with my dealer tech and he didn't know nor had anyone complained. He said the variocam is actuated at 2200 RPM. Another poster spoke with his dealer tech, went for a ride, and the tech said "definitly variocam... some cars have it, others don't (drop)". My indy said it is definitely the variocam and the turbos always did this, the turbos were the first car to get the variocam. True???

I purchased the car, new to me a few months ago and it always did this, I now have 37K miles on it.

Of course I am paranoid that something is amiss (yes, pun intended).

Thanx

Bruce in Philly

Probably the best place to start is to connect a Porsche specific scan tool (PIWIS, Durametric) to the car set in a data logging mode and run the car through the RPM window where you feel this anomaly. You sound like you are in the range where both the cam and valve timing are active, so you are going need to do some data collection to see what is going on at the time. Might help to also have someone in the car with you to note when it occurs to help pin point the variables.

  • 2 months later...

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