So my 2012 Cayman S has been making a whining noise for about a week. It seemingly originated from the accessory drive area - it was independent of vehicle speed, gear selection, clutch in/out, or AC on/off. It didn't appear to be the power steering pump, as there was no change in sound based on load or steering inputs. I've been pushing it for a bit because I live about 3 hours from a Porsche dealer and have been unable to find a time to get there.
Well, today on the way home from work, the noise started getting worse, I got a brief "generator" and "service engine" warning message and light, and I noticed an acrid electrical-ish smell when I shut the car down. To troubleshoot, I removed the front engine cover intending to crank the car and see if I could tell a physical defect. I noticed some metal filings and some burn marks around the alternator face. Could be normal, but I haven't seen this in the past from what I can remember.
Anyhow, so I go to start the car and it won't crank. Seems like a dead cell. With the voltmeter on it, it went from a healthy 12.5 volts to ~5 at cranking. I took the battery to Autozone to double check the cell and (likely get a new one). As soon as I walk in the door carrying it, it explodes on me. Loud bang, acid cloud, plastic mess everywhere. I'm really lucky I didn't get any in my eyes.
Thankfully, they accepted it as a core after scaring the crap out of everyone in the store. I got a replacement battery, headed home, and took a shower scrubbing with baking soda.I figured that was a good stopping point for the evening. So here I sit, still 3 hours from a Porsche dealer, with a new battery, and a possibly dangerous charging system/alternator failure.
Anyone have any ideas or thoughts about what this could be? The car is still under an extended warranty, but I don't trust anyone in this little town to work on a Porsche.
Thanks in advance!
Just speculation, but if the charging system was faulty, it would have exploded the battery in the vehicle. My guess is a faulty battery wreaking havoc on your charging system. Probably creating so much resistance it was bringing the alternator to it's knees.
What were your charging or battery volts prior to the noise? Were they erratic?
+ 1 on the battery theory.
I agree on the battery theory as well because even so-called sealed maintenance-free batteries have pressure relief vents which were clearly not working with yours.
However I would not rule out an alternator/voltage regulator problem. I’ve seen an incorrectly functioning regulator pop the tops off a non-sealed battery before it failed entirely and threw a code.
Are you still getting a noise after replacing the battery?
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WOW. That would have scared the crap out of me for sure. At this point I'd have a tow truck haul everything to the nearest Porsche shop for diagnosis and correction, even if it is 3 hours away. The risk of doing otherwise could be catastrophic. Keep us posted.:helpme:
Yeah I agree with Budman. There's no way I would assume it was the battery and just pop the new one in. This needs professional diagnosis.
Glad you were not hurt, that could have been really bad.
Concur. I contacted Porsche via Twitter and they got back to me within a day. They’ve escalated my case and asked for all the pictures of my hand (cut), leg (acid burn), and alternator. They said they’ll be back in touch within 2 days, but can possibly assist with getting the car to the nearest dealership for a fix. The woman on the phone was exceptionally friendly and caring, so thus far it’s been a positive, hopeful experience.
It would be huge if they came through with a tow and a quick fix. For now, it’s my primary vehicle, so the faster it’s back in action, the easier for the family.
I’ll update when I hear back from Porsche.
I’ve heard of assault and battery before, but assault by battery?!
Hope you’re ok and that Porsche makes it right.
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Minor update - thanks to my insurance's roadside assistance coverage, the 200-mile tow only wound up costing $100 for the over-mileage. One of those thing I pay for but never use came in handy.
The dealer was able to take a look and quickly diagnosed the alternator as toast - "absolutely grenaded" according to the service rep. A new one is on order and should be there in a day or two and the extended warranty will cover it, so just the deductible to pay. I'm just glad they actually found something tangible that caused this pain. A light at the end of the tunnel!
The car is back in the garage with a brand new alternator. Thanks to the extended warranty I purchased, the $1630 fix was covered with the $150 deductible, effectively paying for half the warranty's cost. I'm still waiting to hear back from PCNA to see if they'll do anything to cover the costs, but I'm not holding out too much hope.
For the curious, a 987.2 alternator is ~$1400 (including the $280 core).
Glad no one was hurt with the exploding battery....
Good thing it didn't blow inside the frunk spewing battery acid and possibly denting the hood, resulting in more damage and repair...
WTF?, sounds nuts to me. You mean for the part only?
Did it have an AGM battery?
One last followup. As I said earlier, I'd been talking with PCNA about the incident and they came back with an awesome gift/compensation - a $500 parts/service gift certificate. All told, it basically evens out the new battery cost + towing + warranty deductible, but it's far more than they had to.
/happy customer
