CMiYC

RESOLVED: It was the Voltage Regulator.

Replaced the regulator this morning. Cold start the charging system is stable at 14.4v. After driving a variety of roads, highway, city, and stop/go, the charging voltage is stable at 13.9v. :)

The regulator was about $50 shipped. I bought it from alternatorparts.com. Link to the one I ordered: http://store.alterna...regulator.aspx. The original part number was F 00M 145 225 (something I had trouble finding when searching for just the regulator.)

Thanks to Renntech for being such a great resource!

Originally posted a question about a trick to get the generator out (or in).

Was about to use two chisels as levers to move it around. I wasn't expecting to do so much man handling, but it seemed to work.

Thanks. It took me a while to understand what it was needed for, since I didn't realize there was a dust cover on the Alternator's Pulley.

Just from looking at the engine bay, I'm not seeing why I need the multiple-tooth adapter. I have a 2004 CS4 w/ Manual.

if needed is this tool available at a Sears or AutoZone-type store? I searched the web for the official part and found several suppliers, but was hoping to get this done this weekend.

if I follow this correctly everything now operates normally....

I'm pretty sure that at no time a car's charging system should drop to <11.7V. Nor should drop at a rate of 50mV/second. Which is what my charging system does every time after running for a few minutes. I would not agree "everything operates normally" now.

Using a DVM, Digital Volt Meter, with the engine idling, measure the voltage on the battery posts vs the jumper point in the engine compartment. A difference of more than 0.5 volts might indicate a poor wiring or ground connection front to rear.

This is a great idea. I hadn't thought to compare the difference from the battery posts to the engine posts. The only trouble i'll have with the experiment is moving fast enough from the front to the back. (I don't want to see a big difference in reading, just because of the time it takes to move.)

That's strange, my lawn tractor battery charging system acts the same way. Immediately after starting it the charge rate, current flow and voltage, goes up. Within a few minutes the charge rate declines as does the alternator output voltage.....Strange....?

...

You undoubtedly have a dead cell in your original battery.

The battery was less than 1 year old when the trouble began. Since it was still under warranty, I swapped it for a brand new one before making my original post. Needless to say, it wasn't the battery. I have a new regulator coming so I am going to try that next.

Bummer.

Thanks all.

At a quick glance of this long post, I would think the issue is with your voltage regulator. That will typically cause these odd fluctuations. It will charge, then drop, then charge...etc. Seems very random and haphazard, but it is likely the voltage regulator. That is how they act when they are faulty.....Just my opinion. I would check that out...

My thoughts were moving towards the regulator as well. I just lumped it in with the alternator because I thought the regulator was internal on the 996's alternator. So in order to replace it, I have to replace the alternator anyway.

Is it true the regulator is integrated into the alternator, or am I incorrect?

About a year ago I was driving around and my radio cut-out. This caused me to scan the instrument panel and I noticed my voltmeter was reading ~12V. I shut-off the engine at checked the battery with a multimeter and saw it sitting above 12v. I don't remember the exact reading now, but it seemed normal to me. When I started the car it jumped back up to almost 14v and stabilized there.

About 6 months ago this problem become more frequent. Intermittently I would notice the voltage dropping. It wasn't every time I drove the car, just on occasion.

About 3 months ago the problem became apparent any time I was idling at a long stop light. I could watch the voltage gauge visibly drop to 12.

At this point, after 15 minutes or so the drop happens every time. However, when I restart the engine the voltage will jump back up to almost 14v for 1-2 minutes before slowly dropping back down to 12v. If the Radio and A/C are both on, it will drop below 12v. After shutting off the engine, the battery's voltage will be around 12.5V.

My assumption is that the alternator stops charging and the car is running off whatever is left in the cells. I assume if I left the car idling, the battery would be depleted and the engine would stall. However, even after driving around for 30 minutes and then sitting in the garage idling for 15 minutes, the car never dies. (How long could the engine idle on just the battery?)

I took the car to Autozone, thinking they had test apparatus that was more elaborate than just a voltmeter. (Granted I think their tool can do things like properly load a battery, but really the information it gave wasn't much more than a voltmeter.) Their machine claims the charging system is perfectly fine, even though you can clearly watch the voltage drop 10mV / sec.

Why is the charging voltage jumping up to almost 14v when the car first starts and then dropping? Why does it stay close to 14v when the car is cold but drops faster as the car warms up? In other words, if I let the car sit over night, I see the same behavior as when I immediately swap the battery with a fully charged battery. This was another test I did with Autozone's help.

I assume the alternator needs to be replaced, I'm just curious why it is acting this way (and if it indicates another problem.)

I put NGK in mine at 30,000 miles, 2 years ago. I won't bother making dubious claims of better performance or the engine running smoother or the other general nonsense people use when replacing parts. Replacing worn spark plugs (or any other worn component) is always going to result in better performance. However in the 2 years and 10,000 miles I've had them in, I have not had any issues or "headaches."

Look at the numbers involved. The entire front-end will require reconditioning. New sheet metal. New fender. (I'm not sure but is that part of the frame which surrounds the trunk/boot?) That needs to be replaced/repaired too. A/C fans are probably damaged. There is potential damage to the brake system (sitting in the trunk). The car probably needs a new paint job from having that much dirt sitting on it plus to match all the new parts. The interior needs a serious amount of reconditioning and new airbags. New set of tires. Not to mention the work to recondition an engine that hasn't been run for 3 years. (You should NOT start the engine until you've had a chance to flush the oil and fuel system, and replace the cooling system's radiator.) Front-end suspension is probably in need of replacement as well.

Let's say you have $20,000 in repair work. Are you going to buy this car from the guy for $1,000 or $2,000? Even after spending $15-20k in repairs the car probably won't drive right anyway. If he wants $10,000 or even $5,000 you're close to $25k-$30k!

Why spend all that money and time when you can save a little more and buy one undamaged for $35,000?

NOT FOR DRAG RACING. Its just these douche bags in M3's, corvette's and Sti's giving me problems and always wanting to try to take me at a light.

The 996 is a piece of cake to do. It takes me just as long to get the oil filter off my 4Runner as the complete oil change on the 996. (Joking - somewhat...).

I had a 4Runner so I would agree with your time. My next SUV was a Toureg. I couldn't even get the brush guard off in the time it takes to change a 996's oil.

If it was me and I was concerned about something as serious an an IMS, I'd take it to your Porsche dealer and not mess around with trial and error.

When troubleshooting a problem, the dealership is probably the last place you should take a car.

Oil Spot under car, Could be oil seems a bit more clear

For Sale: Obsolete RMS tool, never used, make offer.

I'll trade you the tool for my MOST-based head unit.

Oh... I also have a BOSE sound system! I have read this configuration (w/ BOSE) means optic fibre MOST. If so would anything will change?

I tried the Aux kits with the CDR-23 and they didn't work. I ended up replacing my head-unit and amplifier.

This may not lead to an answer but I thought your 25/50 speed was interesting.

50mp/h = 80km/h

25mp/h = 32km/h

It is probably just coincident.

Okay so the light came on a couple more times and after 3-5 trips would turn off.

I finally noticed the pattern for when it would turn on. It is only when I have the A/C turned off. After a couple start-stops the light comes on after I start to accelerate. Watching the tach, the RPMs never go over 1,000 while at idle.

Why would the A/C being off cause this error?

Today I noticed my airbag light isn't coming on. It made me wonder if the indicator lights use bulbs or LEDs?

2004 C4S

so what did you do? I am in the same boat. 6 wires to the amp. wtf

Right behind the battery there is a hole with a rubber grommet in it. So I cut a hole in the grommet and ran them through there.

... but arent laser jammers illegal in just about all states? Not that something like that would stop me, but...

Speeding is illegal, so why would anyone that speeds worry about the legality of a jammer?

The lights pulsing with the radio makes it sound like the battery (and/or alternator). Or as RFM suggests, there is a ground problem.

How old is the car and how old is your battery?

There is nothing special about a Porsche battery. Apparently the ink they use to print their name costs $200. Like every other car manufacturer in the world, Porsche OEMs their batteries. It is doubtful the battery itself is the cause a problem.

The Carmax service bay probably does not have the latest Porsche diagnostic tools. So, you can do the same thing Carmax can do, plug a OBD reader into the car and see what error codes it reports (and delete them). If you don't have one, go to AutoZone and borrow theirs.

I'm puzzled why Carmax won't "let you" take the car to a Porsche dealership. Last I checked, you were the driver/owner, not them.

When I did the DIY, I found any variety of extensions were helpful. I didn't have a 4" but made due with other pieces.