My '06 2CS (17k miles) was exhibiting slow, labored starting - almost like a depleted battery - last fall. Taking the car into the dealer for its regular service interval, the service adviser recommended the "wiring harness fix." So, they dropped the engine and swapped out the (supposedly) fried alternator cable.

Problem solved...temporarily.

Now, four months later, the problem is back...this time much worse. Car really cranks slowly and comes dangerously close to NOT starting...but, it does start with great effort.

It's not the battery, as the car is on the trickle charger in between uses. But, now I'm not sure what the problem might be. It went back to the dealer this afternoon - and we'll see what they find.

I know I'm not the only one with this problem, but I'd love to hear from any Rennlisters who've experienced this and solved it. I'm stumped - I just hope someone at the dealer can fix it permanently this time.

I'm used to my 356 being an "adventure" as to whether it will get me home from wherever I drive it. But, with the 997S I'd like to keep the guesswork out of the driving experience.

 

This has been posted here before. The wire to the hot side of the starter is loose, the connection corroded, something like that.

 

As I recall, most that had this issue also had the wiring harness replaced and it seemd to fix their problem. Mr. Brown is experiencing that issue again and has had the starter and the alternator replaced.

 

Are you sure its not the battery this time? Several months ago I suspected my battery was dying and plugged it in overnight to a trickle charger, next morning nothing! Rolled it down the hill, popped the clutch, got it started and drove directly to Interstate Battery for a new battery. I was surprised the battery would just die and not take a charge, but apparently it did. (This was at about 52 months on my 05, daily driver.) Anyway, why take chances? If I were you I would just go get a new TT!

 

Dead battery? Sometimes you can remove it from the car, drop it firmly on the ground, reinstall it, charge it up, and it will run for several more months. (Sometimes the build up of crud on the lead plates builds up and then shorts across them. Dropping the battery shakes that stuff loose and buys you some time. Ultimately, the build of of that stuff from the bottom up will short out the plates).

 

And there it is...once again; the simplest solution is the best one.

I'd be surprised, but happy, if it turns out to be a bad battery. I should find out tomorrow.

 

If it is the battery, don't get the OEM one for mega bucks; Interstate makes one (I think it's H7), fits perfectly, costs about $159, that's what I got.

 

Battery could very well have been damaged from undercharging due to your previous problem. Wouldn't necessarily show up right away.

 

Sorry to hear about that, John. Hopefully it won't cost you much.

I guess now is a good time to remind everyone about proper battery maintenance. Always use a battery maintainer if your car is not a daily driver. And always check the electrolyte level at least twice a year, preferably at least every 4 months - that's what I do.

And when adding water, use ONLY distilled water. And just like when adding oil, never overfill when adding water. The minimum amount of electrolyte solution (water level) that should be in your battery is that amount that covers the plates completely. And the maximum amount is where it reaches the bottom of the level indicator - use a flashlight and pour slowly and stop when the surface tension of the electrolyte closes up the circular opening of the indicator, reflecting the light back at ya. You never want to exceed this water level, or worse yet, fill all the way up. The battery case needs that volume of space for the gases to vent as the battery gets charged by the alternator.

You shorten battery life by either under filling or by overfilling with distilled water. And of course by not using a battery maintainer if your car is not a daily driver.

This has been a public service announcement.

 

I had a very similar problem.
Last October my car died and the dealership diagnosed the problem as a bad alternator and dead battery.
They replaced both under warranty. Then in Jan. of this year the alternator died again and, again, it was replaced under warranty. A couple of weeks ago the alternator died and I now have # 3 in the car. The dealership said the starter, wiring harness, and everything else was OK.

So, I'm waiting to see how far I get on alternator # 3.
Mr. B

 

I've been using the Ctek battery maintainer between drives. However, I've never opened up the battery to check/add water.
Auto Gallery has a "special" on OEM batteries for $199 installed. Reasonable, I'd say.

When this slow-crank symptom originally surfaced last fall, the battery and alternator checked out fine, but the alternator cable was supposedly bad, and it was replaced as the solution.

So, this time, if the battery is, indeed, bad, then something else is going on. I'd really like to get a definitive answer on this one. Hopefully, I'll hear from the tech guys today...I'll report back.

 

I just started using the Porsche Battery maintainer, but that won't solve the problem of a defective alternator.
Mr. B

 

OK. Car is home now, starting up like a 997 with a brand new battery, which is what it has.

Tech assures me that he went over the alternator, harness, and all things electrical - everything looked good. However, two of the battery's eight cells were DEAD. No charge. The cells were not "dry," they were just unable to hold any charge.

That would explain the car's sluggish starting - almost as if it was not getting quite enough juice to crank the starter. It wasn't getting a full-battery's worth of crank. But, my CTek maintainer was keeping the other six cells juiced.

So, original battery has been replaced with a new one. I will keep an eye on it, but I'm hopeful that this will solve the problem.
Fun with cars. In the grand scheme of all the problems I could be having, this is minor stuff.

Thanks for everyone's input. This forum is a real asset.

 

John--glad to hear that puppy is roaring to go again!

If you need someone to "keep the charge up" on any of your Porsches I will leave a couple of my other vehicles out in the drive and keep them in my spare garage space and drive them occasionally. Leave a CC for gas...

 

You're a giver, Dan. Always thinking of others.