Jump to content

The RennTech.org community is Member supported!  Please consider an ANNUAL donation to help keep this site operating.
Click here to Donate

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)

Help! Intermittent rough idle


Recommended Posts

I have an 04' Cayenne S w/ 87K miles. Last month I had a couple of episodes of rough idle/running. (No check engine light.) After ruling out a bad tank of gas and the return of these episodes, I visited my indie mechanic. Scan results showed misfire cylinder 2/6. We replaced the ignition coils at 2 & 6 and cleared codes. Truck ran fine for four or five days and then the intermittent rough idle episodes started again. The second episode triggered the CEL (solid) light. Brought the car in today and the following codes showed:

P0357 & P0021

After clearing the codes, the rough idle returned and I rescanned. P0357 was persistent.

The original coils were replaced under warranty/recall by first owner. Plugs were changed at 65K miles. Wondering if it's time to simply change the remaining 6 coils, or if there are other suggestions?

Many thanks, in advance, for forum input.

post-65996-0-25763000-1358270914_thumb.j

Link to comment
Share on other sites

How you described the problem reminds me to my situation weeks ago.

The coils of course can be the problem. Maybe you should try to replace the remaining ones. Its not that expansive.

But back to the topic...... My problem with the rough idle was the fuel pump. Specially when you wrote it was working some days and after it came back. The reason can be the fuel level in the tank. With tank almost full it works. When you drive some days and fuel level is going down problem is coming back.

The car has 2 pumps. They working both only when you start the car and under full load. In other circumstances just one or the other is working . Search the forum please for

TESTING FUEL PUMPS. You will find some advice how you can find out more

  • Upvote 1
Link to comment
Share on other sites

Can anyone confirm the latest coil part #? The original coils were changed in 07' as part of a campaign. Those coils read: Beru 648 602 104 07 / 0 040 102 002. The two new coils I replaced read: Beru 0 040 102 012. I'm getting some conflicting info from my dealer part's counter. Thank you!

Link to comment
Share on other sites

  • Admin

Can anyone confirm the latest coil part #? The original coils were changed in 07' as part of a campaign. Those coils read: Beru 648 602 104 07 / 0 040 102 002. The two new coils I replaced read: Beru 0 040 102 012. I'm getting some conflicting info from my dealer part's counter. Thank you!

Porsche part number 948-602-104-07 is the latest part (for a MY2004 Cayenne S).

Link to comment
Share on other sites

Thank you, both, for the additional information. I pulled the engine cover to confirm part numbers - the coils replaced under warranty (2007) read: Beru 948-602-104-07 / 0 040 102 002 . (Is the latter part number for vw/audi?) The two new coils read: Beru 0 040 102 012. They seem to lack the Porsche part #?

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • 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.