Jump to content

Server Lease Renewal/Software Licenses

Our yearly server lease, software licenses, as well as hardware operating costs, ARE due Dec 6th, 2021. Our current donations have fallen far short of the funds we need to renew. Please remember the RennTech.org community is Member supported so please consider a donation to help...  THANK YOU!

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)

Intermittent rough idle when engine fully warmed up


Recommended Posts

Hi everyone, I have done some research around this topic but cant seem to find the same symptoms as I currently have. So I have a 2000 2.7 tip with 95k miles, it had a new AOS about 2 years ago and a new MAF 1500 miles ago. Car runs fine apart from a rough idle but only when its fully warmed up. If I drive 20 miles and leave it for a hour, when I start it up again idle is fine until it gets fully up to temp. Any start from cold and its fine initially. About a year ago after a service the mechanic started it up and it did the same thing but cold,  hasnt done anything like this until the last couple of weeks. Oil filler cap comes off easily. Had the inspection cover off and cant hear any vacuum leaks. Cleaned the throttle body about 2 years ago when the AOS went bad, but to be honest it wasnt very dirty. I had it running with the cover off got it up to about 80c close to running temp and it seemed fine, took it for a spin and the fault returned. It does not stall.

 

so any ideas would be appreciated.

Link to comment
Share on other sites

Thanks, its a bit of a trek for me to get the codes read but if that's what I have to do so be it. Was just hoping someone had come across this temp related issue before. Just got back from a 100 mile trip car is fine until fully warmed up then idle stumbles and is slow.

 

Being an E gas car am I correct in thinking it doesn't have an Idle Control Valve.

Edited by timbo
Link to comment
Share on other sites

...Oil filler cap comes off easily.   Had the inspection cover off and cant hear any vacuum leaks....

 

Timbo,

 

During normal running conditions, the car should idle around 680/700 RPM. If then you remove the oil filler cap, that should create a vacuum leak in the crankshaft, and the car should start running rough. The cap should always fit tight when in place.

 

I also don’t think you will be able to hear most vacuum leaks, sometimes they are very small, but enough for having low or no vacuum formed in the system. And you also have 2 systems to troubleshoot: the crankshaft and the intake manifold. This is also where a friend’s smoke machine comes very handy.

 

Cheers

  • Upvote 1
Link to comment
Share on other sites

Right, e-gas has no idle control valve. You may want to try a throttle body recalibration. Turn the key to the last position before cranking and let it sit there for 2min without touching the gas pedal. Then remove key and it's done.

It will also be good to verify the coolant temp reading (via an obdii scanner) when the engine is rough.

  • Upvote 1
Link to comment
Share on other sites

Update, so after a number of longish runs it seems to have settled down now. My theory is that Ive been doing a lot of short runs, the butterfly valve wont have completely closed each time allowing some crud to build up, so when completely warmed up the crud got in the way, the long runs may have cleared it away. coupled with a possible oil overfill. Dip stick says full Dash stick says half full, I think I made the mistake of going by the dash stick.  Changed the oil and filter and went by the Dip stick. Does my theory seem plausible?

Link to comment
Share on other sites

Only if you're extremely lucky.

If you have a smart phone or iPad, a very cheap app is available called Dash Command. $10 via Apple Store. Then a obd2 to plug into the port. I bought a specific one on Amazon that comunacated with my model phone via wi-fi, not blue tooth. I was having some issues and this proved invaluable for a total of $ 40. It also shows a lot of engine info while running. I just kept clearing the code P1126 and trying different things. Good luck.

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.