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Exhaust and startup issues, Need some advise

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Im new to the site, just purchased my first Porsche, 2004 996 C4S cab, 31k miles. I live in PA, flew to mississippi to buy it and drove it home. I purchased the car from the original owner, a 65 year old orthopod (I say this because it means to me that the car was never abused). I purchased the car from the doctor but picked it up at Porsche of jackson following the dealer doing a 30k service, they told me all was well and i need not expect any major cash outflows soon after my purchase. So I drove 1200 miles without a problem, now I'm home in pa and becoming skeptical of my purchase. Here's why,

1. I now hear a light rattle from the passenger exhaust for the first few miles after startup each time I drive regardless of whether I just drove it 10 minutes prior...sound generally goes away after 5 minutes. Checked the cats with mallets, checked the exhaust clamps..can't see a problem..am I over thinking a war up sound, is this normal, or do I have a prob that needs to be checked by a tech?

2. Possibly, and if so, largely my fault...every car I have had as automatic lights, meaning they go off when I turn off the car. Two nights ago I left the headlights on all night, went to drive her in the morning and she was fully dead, had to jump the fuse box etc.. Just to get to the battery, when I did that, the jump wasn't enough to get the engine turned, aaa came and got it going with a power pack. They told me I was at 14 volts, but my cold crank amps were at 490/850, and " I could have a problem in a few days". After this car worked fine beside my #1 issue, and no problems starting or with electrical. Despite having made the car my daily driver since I purchased it last week, today I tried to leave my office and got no start. So I pulled the key out of the ignition, tried again, and it worked...same thing each of the three times I've tried driving it since...is this the battery needing replacement, the start, or something else? I figure the battery, but why the problems after two days of continuous driving?

Some of my coworkers have Porsches and all of my family are life long owners too, they all think I am overthinking everything. My father is a VW, Mazda, and Volvo dealership owner, and other dealership owner in the past he thinks the exhaust noise is "normal".

Comments and/or suggestions would be appreciated.



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1. Did you check the heat shields near the mufflers - they are know to rattle if bent (like after a major service).

2. Do you know the age of the battery? Did they check the specific gravity of each cell?

If the battery is over 4 years old - replace it. You don't need those headaches.

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Thanks for the response, did not check heat shield, how easy is this for me to check, can I do It on my own, or do I need to bring it in? Definitely replacing battery based on cold crank amps negativety and knowing the battery might not come back... I'm concerned it may not be a battery problem though....

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As long as the engine is cool to touch then the heat shields can be inspected and bent so they don't touch during road or engine vibrations.

After you change the battery use an ammeter to measure the current draw with the car off (but unlocked) -- it should be around 40-60 ma. If it is much more then there is a drain somewhere.

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So this won't cost me $3k...talked to local dealer today, they said they would "identify" or confirm no power drain and change battery for $400+/-. Heat shield isure can be played with by any tech? My father is a VW dealer and told me his guys could fo it for cost of battery, but he always had work done by authorized dealers. think I should bring to Porsche dealer or let his techs play with it? Thanks

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You can buy 4 batteries for $400 or two AGMs. Don't let the Porsche name scare you into buying commonly available parts from dealers.

" ...So I pulled the key out of the ignition, tried again, and it worked...same thing each of the three times I've tried driving it since...is this the battery needing replacement, the start, or something else?"

You might need a new ign switch (not uncommon). <$20 and relatively easy DIY NAPA 4A0905849B Or talk to your father same on many VWs.

Edited by fpb111
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If you search this forum I think you'll find a few articles on getting a new battery from Wallmart. They have a good quality battery that is the right size for less than $150 if I remember right. I'd replace the battery first and see if that helps.

When I first got my car I was worried about replacing with non-Porsche parts...but that worry fades pretty quickly especially for things like batteries, brakes etc.

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