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)

Recommended Posts

Hi Guys

I own a 2006 997 C4S which I bought 10 months ago. The car has now done 30 000km's. I have noticed a progressive slow cranking over the last few weeks. I use the car on a daily basis for short journeys. When I had it serviced recently I asked the dealer (350 km away) to check the battery due to the slow cranking. They reported that the battery was fine. On Friday the car would not start at all. I removed the battery and had it tested at a battery shop where they said it was fine, just completely drained. What do I do now??

I had the same problem with my previous car, a 996, last year, when I gambled and tried to drive to the agent. I made it half way before the car stopped in pouring rain with the battery dead in a remote area. Not something I would like to do again...

I would really appreciate any suggestions.

Etienne

South Africa

Link to comment
Share on other sites

  • Moderators

If the battery is draining but otherwise good, and there are no undo parasitic drains on the system, you probably have a problematic alternator. Check for electrical drains by putting a digital voltmeter set to current (mA) between the positive battery cable and the positive battery terminal. You should see something around 60 mA or less (normal current draw). If it is higher, something is pulling current out while the car is parked. You can locate the circuit by pulling the fuses one at a time until you see the draw drop into its nominal value; the fuse you just pulled is the problem circuit.

As for the alternator, you can use the same meter to check the voltage output at idle, should be 14.3V or so. If it is below 14V, you probably need a new voltage regulator for the alternator (same regulator is used in Audi, Mercedes, and VW cars, so you should be able to locate one).

Link to comment
Share on other sites

If the battery is draining but otherwise good, and there are no undo parasitic drains on the system, you probably have a problematic alternator. Check for electrical drains by putting a digital voltmeter set to current (mA) between the positive battery cable and the positive battery terminal. You should see something around 60 mA or less (normal current draw). If it is higher, something is pulling current out while the car is parked. You can locate the circuit by pulling the fuses one at a time until you see the draw drop into its nominal value; the fuse you just pulled is the problem circuit.

As for the alternator, you can use the same meter to check the voltage output at idle, should be 14.3V or so. If it is below 14V, you probably need a new voltage regulator for the alternator (same regulator is used in Audi, Mercedes, and VW cars, so you should be able to locate one).

Thanks very much for this very informative reply, much appreciated!!!

Take care

Link to comment
Share on other sites

Also have the cable from the battery to the starter motor checked. I believe there was a Porsche campaign (ie. recall) to correct or replace this cable. Might be a 'high-resistance' or loose connection.

Do a forum search on this topic . . battery cable, starter cable, etc.

Edited by AP 997S
Link to comment
Share on other sites

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
×
×
  • 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.