Jump to content

Server Lease Renewal/Software Licenses

Our yearly server lease, software licenses, as well as hardware operating costs, WERE due Dec 4th, 2022. 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)

2004 CTT hard downshift

Recommended Posts

So I took my new to me 2004 CTT for my first real longish drive in it today (4 hours), and noticed a new problem. After running on the highway for a while, occasionally on the faster side (140-150 kph), when I would go to slow down I would get jarring downshifts from 5-4, and occasionally from 4-3. Turning the PSM off got rid of it, and it doesn’t happen in normal city driving or cruising at more prescribed speeds like 110 kph. Now, I’ve read all the info about the transmission valve body going bad, but mine was replaced not long ago. Does this suggest anything other than a serious transmission issue, like the tranny fluid should be changed or there is a vacuum leak somewhere? It also seems really determined to learn my driving style when the PSM is on; accelerate hard a few times and the shift points move up for the next few minutes – could this be a training related phenomena? I usually leave the PSM on; goes great with it off but it really kills my mileage! Thanks.

Link to comment
Share on other sites

Yes; are you thinking a vacuum leak could do this? The work on the MAFs was somewhat successful – after draining the oil from the intercooler hose I cleaned the MAFs yet again, and this time it seems to be lasting longer. The idle gets rough much less often, and starting has been better overall. But I do suspect some airline problem, as it now does sink to 400 rpm then pick back up again to 580, which is often a sign of a vacuum issue. So I’m thinking since the transmission hard downshift is only after the throttle has been open a lot, the two could be related. Just not sure which lines might be the culprit. I guess a smoke test is in order.

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.

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.