Jump to content

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

2009 C2S - 2700 RPM drop/thump

Bruce in Philly
 Share

Recommended Posts

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

Link to comment
Share on other sites
  • Moderators
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.

Link to comment
Share on other sites
  • 2 months later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.