'05 Carrera Occasionally Won't Crank

[zclaymore]

I have an '05 Carrera w/18k miles that occasionally won't crank. It usually occurs after driving it for 10-20 minutes and then attempting a re-start within 15 minutes. Hooking up a battery booster starts it right back up. Checked the battery after sitting overnight - shows about 11.5v. With the car running - I'm seeing 14.0v. I haven't had a voltmeter handy when the problem occurs so I'm unsure of the reading. I'm suspecting the battery though the intermittent nature of the problem has me second guessing. Any ideas? thx in advance.

[Loren]

:welcome:

How old is the battery?

If it is 4 years or older I would start by replacing it - you are on borrowed time with a battery that old.

You can also check for power drains - 3rd party accessories (i.e. radar detector, GPS, etc.) that are drawing power with the car off.

[355bhp]

Same thing with me. It's time for a new one.

[grujfo1]

i had similar issues from the beginning. in my case, "everything" (battery, starter, alternator) always checked out fine. one day, i went in to see the service manager about this problem and it just so happened that he stepped out and there was this young mechanic in my sight. long story short, he said that there is a known issue with "some" 997.1: apparently there is a cable that connects the battery to the alternator (or something like that). this cable is, well, problematic. there isn't enough of a charge, current coming to and from the battery because of this. result, cranking issues, low rpm issues, shifting issues...anyway, i had mine replaced and the car now cranks up quick. the extended warranty i purchased doesn't cover the particular item and hence i had to pay quite a bit for labor (slightly under 1K).

of course, i'm not saying this is your problem, but....

[g.lu]

i had similar issues from the beginning. in my case, "everything" (battery, starter, alternator) always checked out fine. one day, i went in to see the service manager about this problem and it just so happened that he stepped out and there was this young mechanic in my sight. long story short, he said that there is a known issue with "some" 997.1: apparently there is a cable that connects the battery to the alternator (or something like that). this cable is, well, problematic. there isn't enough of a charge, current coming to and from the battery because of this. result, cranking issues, low rpm issues, shifting issues...anyway, i had mine replaced and the car now cranks up quick. the extended warranty i purchased doesn't cover the particular item and hence i had to pay quite a bit for labor (slightly under 1K).

of course, i'm not saying this is your problem, but....

I'm interested in this. Sorry to ask but is there way for you to lookup what was replaced (part number or text description)? I'm guessing it must the alt to starter cable that is flakey. The battery to body + starter must be good otherwise the booster wouldn't work. But a low current handling connection from alt would lead to an undercharged battery.

Thanks in advance.

[zclaymore]

Thx to all for your responses. I bought a new battery yesterday as a first step. It seems to work great - the car hasn't cranked that quickly in months. Hopefully it lasts and doesn't turn out to be something more complicated.

Ron

[number9ine]

i had similar issues from the beginning. in my case, "everything" (battery, starter, alternator) always checked out fine. one day, i went in to see the service manager about this problem and it just so happened that he stepped out and there was this young mechanic in my sight. long story short, he said that there is a known issue with "some" 997.1: apparently there is a cable that connects the battery to the alternator (or something like that). this cable is, well, problematic. there isn't enough of a charge, current coming to and from the battery because of this. result, cranking issues, low rpm issues, shifting issues...anyway, i had mine replaced and the car now cranks up quick. the extended warranty i purchased doesn't cover the particular item and hence i had to pay quite a bit for labor (slightly under 1K).

of course, i'm not saying this is your problem, but....

I'm interested in this. Sorry to ask but is there way for you to lookup what was replaced (part number or text description)? I'm guessing it must the alt to starter cable that is flakey. The battery to body + starter must be good otherwise the booster wouldn't work. But a low current handling connection from alt would lead to an undercharged battery.

Thanks in advance.

There was a previous topic on this. Apparently the part corrodes and causes slow cranking:

http://www.renntech....ranking-normal/

No quoted part number, but it should be easy to explain at the parts counter. If you have a Tip it'll be a lot of labor, supposedly it's easy with a manual.

Mine cranks a little slow sometimes, I'm going to get under there some weekend and have a look.

Mark

Edited May 3, 2010 by number9ine

[geoff]

i had similar issues from the beginning. in my case, "everything" (battery, starter, alternator) always checked out fine. one day, i went in to see the service manager about this problem and it just so happened that he stepped out and there was this young mechanic in my sight. long story short, he said that there is a known issue with "some" 997.1: apparently there is a cable that connects the battery to the alternator (or something like that). this cable is, well, problematic. there isn't enough of a charge, current coming to and from the battery because of this. result, cranking issues, low rpm issues, shifting issues...anyway, i had mine replaced and the car now cranks up quick. the extended warranty i purchased doesn't cover the particular item and hence i had to pay quite a bit for labor (slightly under 1K).

of course, i'm not saying this is your problem, but....

I'm interested in this. Sorry to ask but is there way for you to lookup what was replaced (part number or text description)? I'm guessing it must the alt to starter cable that is flakey. The battery to body + starter must be good otherwise the booster wouldn't work. But a low current handling connection from alt would lead to an undercharged battery.

Thanks in advance.

There was a previous topic on this. Apparently the part corrodes and causes slow cranking:

http://www.renntech....ranking-normal/

No quoted part number, but it should be easy to explain at the parts counter. If you have a Tip it'll be a lot of labor, supposedly it's easy with a manual.

Mine cranks a little slow sometimes, I'm going to get under there some weekend and have a look.

Mark

The other weekend, my local dealer did a customer appreciation day for PCA members - free under car walkthrough with the mechanics, 15% off for parts and service - and free food. The mechanic looked at the cable from the alternator to the battery to see if it was original or the upgraded Porsche one, and said there is a factory service campaign to replace the undersized original ones (mine had already been replaced by Porsche during an earlier service without even asking). Several hours of labor with the car on a lift, but Porsche should pick up the tab, even though my car ('05 997) is out of warranty. Before buying a new cable, you should probably check with your favorite dealer service department to get the whole story and see if the cable upgrade is covered

At 5+ years, they did admit the battery was pretty much at the end of life and suggested replacing it. He's seen the Optima I put in my Boxster and didn't even bother suggesting to put in one of the dealer's replacement batteries. I recently replaced the 8+ year battery on my Toyota pickup (it started just fine, but the battery was 1½ years beyond the warranty), and I was amazed at how much better the car started and how much brighter the headlights were

[grujfo1]

I'm interested in this. Sorry to ask but is there way for you to lookup what was replaced (part number or text description)? I'm guessing it must the alt to starter cable that is flakey. The battery to body + starter must be good otherwise the booster wouldn't work. But a low current handling connection from alt would lead to an undercharged battery.

Thanks in advance.

1. part number 997-607-019-03 ("alternator/starter harness", "alternator/starter cable loom")

2. funny thing, i had previously visited several dealers in this country about this (i put 50K miles on this thing last year). everyone said it cranked fine though it never did feel right. i had to have several jump starts but i attributed it to the hot water boiler that i use to make coffee with on those camping trips. what i didn't know was the significance that the INTERACTION between direct and alternate current has on low rpm, cold running, and transitions (shifting, double clutching). admittedly, i was unable to articulate the problem "soon enough" and paid for it.

3. if you haven't already, the post that number9ine mentions is a good read

[grujfo1]

The other weekend, my local dealer did a customer appreciation day for PCA members - free under car walkthrough with the mechanics, 15% off for parts and service - and free food. The mechanic looked at the cable from the alternator to the battery to see if it was original or the upgraded Porsche one, and said there is a factory service campaign to replace the undersized original ones (mine had already been replaced by Porsche during an earlier service without even asking). Several hours of labor with the car on a lift, but Porsche should pick up the tab, even though my car ('05 997) is out of warranty. Before buying a new cable, you should probably check with your favorite dealer service department to get the whole story and see if the cable upgrade is covered

At 5+ years, they did admit the battery was pretty much at the end of life and suggested replacing it. He's seen the Optima I put in my Boxster and didn't even bother suggesting to put in one of the dealer's replacement batteries. I recently replaced the 8+ year battery on my Toyota pickup (it started just fine, but the battery was 1½ years beyond the warranty), and I was amazed at how much better the car started and how much brighter the headlights were

lucky you!

[RFM]

A reasonable labour time to replace the cable by a experienced person is approx. 1.h 00 for a manual transmission and 1.h 30 for a Tiptronic.

[grujfo1]

A reasonable labour time to replace the cable by a experienced person is approx. 1.h 00 for a manual transmission and 1.h 30 for a Tiptronic.

wow...looks like the dealer ripped me off.

[sausage]

Just to add: 11.5 v in a 12v battery means the battery is ruined. However, I would not expect to have to change a battery just because it is four years old. On my yacht I have 5 12v batteries which are constantly monitored for charge rates, standing volts when no charge or drain is there and also how long before the battery drops voltage when in use with no charging. I cant remember the rules on the decimal points, but 11.5 v is definately knackered.I think they should maintain about 12.2v but Its been a while since I read the engineering facts on batteries.

I rely on my batteries for navigation, depth sounding, wind instruments, VHF radio, SSB radio, Navtex weather reports, laptop, lights etc etc. They are critical to my safety and I sail solo and have been as far as UK to the Meditterranean. My batteries are older than four years and I have no concerns about them. This idea that they need changing every 4 years reminds me of the idea that brake discs need changing at xx,xxx miles. If they are still good, they dont need changing.

[AceOfAces]

I'm glad you wrote this thread, my 05 C2S occasionally doesn't crank as well which connecting my 12v battery charger helps. My trips around town are usually quite short since I live in a small town, I know the car's computer system and any peripherals are still drawing current when the cars turned off. I had the battery and alternator checked at my mechanics, they said it was okay and I shouldn't need a battery change for another 2 years or so. I've read a lot about that thin cable that connects the battery to the alternator as a known issue in early 997's, I think I'll ask them to check it out and test it on my next service.

Thanks for all the suggestion, this is a really useful thread to help others troubleshoot their issues. Wish you all the best of luck :king:

[brendel]

A good battery has 12.7 V

A weak battery start at 12.2V and below when disconnected

I got stuck last week in an underground parking, I bought a new porsche battery, the Moll one, the newer version has a short circuit current 40 Amp higher ( not talking about the Capacity that remains at 80AH), I hear the starter engine being much faster than before

The old Moll had a short circuit of 340 A ( german norm) the new one has 380 A

[motosport3]

On 5/4/2010 at 7:09 AM, RFM said:

A reasonable labour time to replace the cable by a experienced person is approx. 1.h 00 for a manual transmission and 1.h 30 for a Tiptronic.

I was quoted 6 hours for this for labor of $1200....