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)

Recommended Posts

I have a 04' Turbo, cooling system replaced about 30K ago. Now that winter is upon us this may sound like an odd question. It was 40' (F) yesterday and I was waiting in the parking lot to drop off kids. When I looked down the car temp was at 220+ but not yet 240. The A/C was off and I had turned down fan/heater 10 min earlier since car was hot inside. I turned the A/C on and the temp went back to 180, if I turn A/C off the temp rises. This is while parked. I will try using the heat tonight when I pick up my wife, I dont know if the A/C fan kicks on for heat.

No codes on Durametric, otherwise the car runs fine and does not get hot in traffic. Then again I usually have the A/C on.

Any suggestions?

Link to comment
Share on other sites

  • 3 weeks later...

I just replaced the big radiator fan. With A/C on, the fan works. With A/C off the fan comes on at around 220ish range, low speed. When I shut the car off the fans do not stay on. Using Durametric there are no codes. It is winter so its cold out, so the car runs 180. Does anyone know at what temp or condition would cause the fan to kick in at high speed or what conditions to induce the fans to remain on after the car is off for that "after cooling" period.

Much Thx

Link to comment
Share on other sites

  • Admin

From the Porsche Tech Book...

"The thermostat starts to open at 83ºC, lift is 9.8 mm at 98ºC, and it reaches its maximum opening at 105ºC. Coolant temperature is measured at the engine block inlet."

The thermostat is is not fully open until 105 C - or 221 F. So that sounds normal.

Also...

"A supplementary electrical run-on pump provides circulation in the coolant circuit even after the engine has been switched off. Depending on coolant temperature and the last driving cycle (map derived from fuel consumption) this pump is actuated by the DME control module through a relay."

So it would appear that the fans do not run with the engine off - but an electric pump does.

Link to comment
Share on other sites

Good to go, just want to get resolved before Arizona summer. It started this summer, but only on highway at high speed. The temp would rise past 220 and hit around 240, but if I slowed down the temp would drop. I would run 180 if stuck in traffic in 110 degree heat, but run hot on hwy. I noticed that the loud airplane sound ( I guess fan at high speed) was no longer present after driving, I just did the pipes/water pump etc 10K ago.

Link to comment
Share on other sites

The fans can and do run with engine off. I have heard mine on several occasions.

Here's why as explained in the Porsche Service Information Technik section 2 page 45.

Fan Run-On

To cool the engine compartment the fans are switched on with the ignition OFF, depending on coolant temperature and the last driving cycle (map on fuel con- sumption). The switch-on threshold is between 90 °C and 93 °C and running time is between 15 seconds and a maximum of 13 minutes. Once fan run-on is concluded, the fans will not start again with Engine OFF.

In the Cayenne Turbo, the electric coolant run-on pump, which provides cooling for the turbocharger (to prevent oil coking), is activated through this function. The run-on pump is located behind the left front wheel wheelhouse liner. In addition, this pump is activated on the Cayenne S and Cayenne Turbo by the air-conditioning control module to utilize residual engine heat.

Edited by bigbuzuki
Link to comment
Share on other sites

  • 11 months later...

In the Cayenne Turbo, the electric coolant run-on pump, which provides cooling for the turbocharger (to prevent oil coking), is activated through this function. The run-on pump is located behind the left front wheel wheelhouse liner. In addition, this pump is activated on the Cayenne S and Cayenne Turbo by the air-conditioning control module to utilize residual engine heat.

Bigbuzuki....

DO you have picture or part number for this pump?

Thank you

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.