Well, I made off for Indiana early this morning, and got about 20 miles before I realized my dash lights looked pretty dim; I checked the **** as my dash lights always seem pretty dim, and rotated it a bit. A few minutes later it occurred to me that my headlights looked a little dim as well, compared to some others. Checked for the battery light, nothing there. Finally I knew something was truly up, pulled off the highway with the other driver coming west with me, and as we left highway speeds the car began to run very poorly, barely keeping idle. Still no battery light.

Shut the car down, battery's near-dead (turned the car over, wouldn't start, radio station presets reset themselves to factory).

I've been flatbedded back to the house. I assume a bad alternator? Unfortunately, all of my useful tools are at the shop an hour away, I've just sold my 2nd car so I'm fairly well stranded here, with only the factory toolkit & a few hand tools at the house; I don't have any of my jump packs or charger here either.

FYI, battery's a crappy Duralast from the PO, and the fan shroud was very hot to the touch an hour after shutting down while waiting for the tow (~75 deg temps overnight). Fan belt was on very well, doesn't appear to have been slipping.

Only other hint I had this weekend - after getting stranded on the side of the road Sunday when the clutch cable slipped out of the trans-mounted bracket, and had the hazards on for about a half hour, I fired the car up to keep it from draining the battery. After the flatbed brought me home and I got the cable in the bracket again, I went to go for a brief run down the road to verify clutch action, and noticed the battery light flickering, then it went out. I figured it was related to running the hazards for the half hour on the side of the road.

Could the bulb have burned out, and the alt let go? Any other thoughts / clues / indications? Intent now is to remove the alt & bring it somewhere for testing, likely replacing the alt & battery concurrently, going with a Diehard Gold, if that size is available.

Thanks for the insight, didn't find so much relevant when I went searching.

 

pics:

http://www.sinclairmfg.com/fred/911/dcp_3225.jpg
http://www.sinclairmfg.com/fred/911/dcp_3226.jpg
http://www.sinclairmfg.com/fred/911/dcp_3227.jpg
http://www.sinclairmfg.com/fred/911/dcp_3228.jpg
http://www.sinclairmfg.com/fred/911/dcp_3229.jpg

FYI, local Porsche dealership was $330 for a reman'd alternator, same price as Autozone, both available next day, Porsche was $35 core, AZone was $65 core.

I found a place online (starters-alternators.com) that said it was the same as an unknown year VW Golf, for ~$230. I wasn't willing to take the chance (and wait for shipping), as the 911's now the only car I've got. After 2 tows in 3 days, it won't be my only car for long, but it'll still be the 1st one I'll want to drive.

Edit: What's up with the crud on the intake sides of the cylinders? Is that something like an intake gasket that needs to be done?

 

Hi Fred,

You don't really know that the alternator is bad until you put a new battery on and fire it up. Put a voltmeter across the battery teminals. With a full electrical load (lights, ac, defroster, etc.), a good alternator will put out a minumum of 13.5 volts at idle, and a max of 14.4 at 2500+ rpms. I don't know specifically what the Carrera's alternator specs are but, for reference, I got about 14v idle and 2500rpms on my 993 when I replaced that alternator. Hope this helps.

Edward

 

turn on your key and make sure that the battery light in the dash ACTUALY lights up. if that light doesn't light up, your alternator field wire is no good or your alternator is shot, probably the later, but I have seen the bulb burn out after one tech tried two alternators and couldn't figure it out.

That crap on top of the fins is the normal dust/oil mix from the last 20 odd years, If your thermostat, breather hose, and oil pressure switch are leaking, it can add to this along with through bolt o-rings, and cyl base gaskets. if it doesn't have a major leak, I wouldn't worry

 

Already did the key-on test for the batt light, got nothing, so I placed the order for the new alt & already picked up a new DieHard International (whatever that is vs. a "Gold").

I didn't see any over-spill in the battery area, so I didn't think the voltage regulator was necessarily toast. I'll be bringing in the alt tonight / tomorrow morning (basically, as soon as the wife lets me steal her ride), to have the thing tested out anyway.

Assuming for just a second that the bulb's burned out in the dash, is this an easy replacement?

Also, the pass. side where the photo showed the buildup, one of those cylinders is oil-wet on the bottom side (not bad, but still visibly wet). I consider it bad for 2 reasons - lower cooling efficiency, and, oh yeah, fire.

Thanks for the info guys.

 

oil has to get damn hot to just combust (flash point is usually 420 degrees plus) just to give off flamable vapors that could be ignited by flame. I would be more worried about a leaking base gasket and a possible broken head stud. If it leaks from there, remove the lower valve cover on the leaky side and try to re-torque the head stud nuts, if you get one that spins, thats that and one is broken. if they are loose, then you are lucky ducky.

as far as the light grab the oil temp/pressure guage and yank it out, the light is on the back, make sure if it is bad, relpace it with same wattage. to test it just apply power to it and see if it lights up.

 

After telling me that they could indeed test the alternator, Autozone somehow realized they couldn't test the alternator after all once I brought them the alt.

So, I rolled the dice, went down to Inskip Porsche today & picked up the alt. While it was out, I figured it was a decent time to clean things up a tad, so I hand-cleaned the fan & housing, sprayed the fan a mid-gray and the housing a semi-gloss black. Out of the car, it looked fantastic. I was considering a BBS-gold on the fan, in anticipation of trying to get some gold BBS wheels someday, but the goldish colors they had were pretty in-your-face.

Unfortunately it took some jockeying around to get the thing back in, and there were some scratches / paint lifting areas during handling. I tried touching up with a q-tip, but it's not nearly as pretty as on the bench unfortunately.

With the alt & new battery in, WOW, I have LIGHTS!
The battery / indicators are much brighter than they have been since owning the car. The key-on / battery light worked on re-install, so looks like the alt really was toast.

The shims were 5-in / 1-out, I left them like that & have good tension. The old belt was cracked badly, so I replaced with the one in the toolkit. I'll be heading out to get another spare replacement for it, as well as a new one for the AC (I considered leaving it off, figuring less drag on the engine).

Thanks to the folks here, and to Wayne's 101 Projects book, as well as the Pelican Site's writeups.

Just curious, is the rear shroud / deflector behind the alt really necessary? I see the 2 fins behind there, which look like they'd direct air to the driver's rearward cylinders, but nothing on the pass. rearward.

Here's the finished product, the black touch-up spots have dried, so it's a little less obvious now vs. when the photo was taken.

http://www.sinclairmfg.com/fred/911/dcp_3231.jpg