When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Whew that was a close one... Alternator on the fritz?
Good evening all,
Hopefully your evening was less eventful that mine! Started up the Turbo this morning to take a nice drive to work and it took a couple more cranks than normal. I thought it kind of odd, but it hadn't been run in about 4-5 days, so I really didn't think anything of it. The drive to work was just fine, car behaved perfectly like it always does. Fast forward to this evening when I was ready to go home, put the key in the ignition and tried to start the engine... all that ensued was a bunch of very rapid clicking, and dashboard lights that would make a Christmas tree jealous! Tested the battery and it was only at about 11.5 volts. I thought, "OK well as long as I can get it started my 50 minute drive home will not be too bad". I had a mobile battery pack in my office with jumper cables so I was able to get the car started no problem. On the way home the car drove fine but the voltage level on the dash kept slowly moving downward. I got about 20 minutes from the house and it was to a level (needle was on the top of the "1" in 10) that was making me quite nervous. I got about 5 is minutes from the house and it finally hit rock bottom and the battery light on the dash came on. The PSM light would also flick on if I let the engine go to idle, but would promptly go away with any throttle applied. As soon as the Battery light came on the voltage instantly went back to 12.5 volts. At this point I was pretty sure I was running on alternator only. I get to the street adjacent to mine and the dash just starts lighting up one at a time of systems failing..... I turned on to my street, the engine finally cuts out and I coast to a stop in front of my house ! My wife even had the garage door up for me so I could pull the car straight into the garage.
With the car all but dead in the street, I checked my records to find that the battery was indeed a few years old. At this point I was pretty much thinking it was an alternator, but figured a battery replacement couldnt hurt. Got the battery replaced this evening and the car started right up with no warning lights. I was able to pull it into the garage finally. I noted that the volt meter on the dash only read around 12.5 instead of mid to high 13s I believe I am used to seeing.
So what do you guys think? Do you think its the Voltage Regulator, or should I just get a re-manufactured alternator and call it a day?
Worst part is, I have an AutoX event I was looking forward to on Sunday. That doesn't look to be happening with the Porsche... Maybe the old GTI will get to stretch its legs.
That's what I'm thinking about doing. My luck, I would replace the regulator and then the rest of the alternator would go. Either way, the Turbo is going to get a new serpentine belt out of the deal.
Anyone know what the normal voltage level I should see when I start it up in the morning? I was reading one post on 6speed and someone mentioned that when the voltage regulators are bad they will read low when they are hot and then function more normally for a little while before they heat back up and fail again.
should see at least 13volts at fire up, really ~13.5V and higher is 'correct'
it's worth pulling the alternator and spending 15minutes to inspect it...a voltage regulator might save the day...if the contacts on the shaft are worn or the bearings are bad, it's probably worth a rebuilt unit vs repairing...depends on your time 'value'
My luck, I would replace the regulator and then the rest of the alternator would go.
therein lies the potential "downside" to only replacing the VR once you go thru the hassle of pulling out all the stuff to get to it. most pros would advise against (a) only replacing the VR for thaw reason you cite, and (b) it's 600 bucks for a brand new bosch and there are many places to save money on general upkeep of the car, and i think the alternator should not be one of them.
the only time i myself would attempt a r&r of just the 40$ VR is if i was able to DIY it. if not? it is NOT worth taking the chance if one is paying normal labor charges even though it's essentially a one hour R&R.
though the fact remains, it could well only be the VR and,.. you still gotta take it out to make that determination! go NEW... don't refurb the alt lol
I would do a little testing before I spent the $ on a new alternator. I don't think the dash gage is all that accurate. Start with a fully charged known good battery and check the voltage at the battery. Start the engine and check voltage at the battery with the engine running - it should be around 13.5 or slightly better - that would show there's current going into the battery. If the voltage is less than the battery was before starting the engine then you are discharging and need to pull the alternator.
Maybe someone can chime in with a better test description than this, but that's how I'd start. Don't count on the dash gage; they can be all over the place.
Last edited by Last930; 05-21-2015 at 06:34 PM.
Reason: Difficulty with spelling
^ good points but as mine failed the dash lights confirmed that with no ambiguity at all. it wasn't all over the place, it dropped straight maybe 11 and just kind of hung there lol
So I started up the car yesterday morning after this whole fiasco and believe I confirmed that it is the alternator. I have a new one with pulley on order to be delivered early next week. Should not take too long to install. I did hear a strange small wizzing noise for about a second when I turned the car off after taking this pic. The battery light was on when I started it up, and the battery is brand new. I just replaced it yesterday with a new one. Im wondering if a bearing didn't go bad on the alternator.
I had the identical problem last month and had to decide whether to order a new alternator or just a voltage regulator. I ordered a voltage regulator from pelican parts, pulled out the alternator using some DIY guides here, replaced just the voltage regulator, and I'm back on the road!
I spent about two hours pulling the alternator and putting a new voltage regulator on, and another hour getting it back together. $40 and I'm good.
My symptoms were very similar to yours. Tried to start the car and it wouldn't start. No prior issues. Had an old battery so I replaced it. Had only 12 volts reading on voltage gauge on dash after replacing the battery. Now I have 13.5 volts when running.
I'm not saying it's not reasonable to go ahead and just replace the alternator if you have it all apart. But for $40 I am happy for now.
It's funny how Porsches watch out for their owners. I've never had one let me down and strand me on the street. Maybe it's just 31 years of pure luck but mine always seem to give me enough warning that I either don't leave the house or I'm able to get back. I had a clutch pedal cluster spring break on my 911SC when I shifted from 1st to 2nd and I was able to do a quick u-turn, coast back down the hill (opening the garage door as I went) then coast to a stop inside. They're not perfect but they're pretty darn strong. It's amazing yours made it as far as it did with that low battery voltage.
I see of course Porsche OEM is more then Bosch which makes senses but the rebuilt OEM is also more then Bosch rebuilt. My point is the OEM more to rebuild and when you send your OEM core are you losing value. Doesn't really matter just something to think about lol.
It's funny how Porsches watch out for their owners. I've never had one let me down and strand me on the street. Maybe it's just 31 years of pure luck but mine always seem to give me enough warning that I either don't leave the house or I'm able to get back. I had a clutch pedal cluster spring break on my 911SC when I shifted from 1st to 2nd and I was able to do a quick u-turn, coast back down the hill (opening the garage door as I went) then coast to a stop inside. They're not perfect but they're pretty darn strong. It's amazing yours made it as far as it did with that low battery voltage.
Interesting you say this. I have had similar experiences with Porsches too.
One time my 356 broke a throttle linkage rod pulling out of my driveway. I pulled over, walked up to my garage and grabbed a jack and some wire, rigged up a temporary fix and drove it back into my garage and ordered a new rod online.
I have had the same luck with the Jeeps that I have owed. Built tough I guess.
I was under the impression that the Bosch is the OEM part supplier for the alternator. The price retail for the porsche part is rediclious. $1300 is a bit much. Is not a unicorn blood injection system lol. The best thing was I had a gift card for ecs tuning and it only ended up being $280 all said and done. Pretty cheap insurance, and it takes care of the whole unit and pulley all in one fel swoop. Thanks for the comments so far everyone! And I do agree ot has been a well built car so far. Only problems Ive had so far are the fuel pump and alternator.
05-20-2015, 10:15 PM
Whew that was a close one... Alternator on the fritz?
! My wife even had the garage door up for me so I could pull the car straight into the garage.
!["02996ttx50's Avatar](data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 50 50'><circle class='avatar-circle-default' fill='%23759d7b' cx='25px' cy='25px' r='20px'></circle><text class='avatar-text-default' x='49%' y='53%' fill='white' text-anchor='middle' alignment-baseline='middle'>"</text></svg>)
