Hi all,

How reliable is the autozone battery test and alternator? out of curiosity I went over to Autozone to get my battery/alternator tested because I noticed a very slight hesitation when cranking over, also I was listening to my engine note changing when I was turning side ways my steering wheel or my heated seats or windows up, the idle was dropping and picking up again and quick light engine vibration, also erratic idle
btw this is a 14 base Panamera with 12k miles
this morning before turning on the car, I think my A/C was on for maybe 10 sec and then the battery discharged display came up.

1st- NTB in the morning I was told, battery good but low on charge.
2nd- morning OReillyAuto- I was told the alternator failed
3rd- mid morning Autozone- I was told everything checked ok, the starter was failed.
4th late afternoon firestone autocare- I was told everything is fine.
5th- Porsche Dealer won't even waste my time going there, always they come up with the BS that everything is normal as this are performance cars.



any help is much appreciated

 

Try to use an external charger to charge the battery up to max. See if that makes a difference. Besides that, it sounds pretty normal the rest of what you describe.

 

What I dont think its normal, is the rpm dropping everytime something is turned on, for example heated seats.

 

I would expect the RPMs to drop when you load up the electrical system.

 

Agree, normal response. Just to be certain though, see what occurs when the battery is fully charged.

 

I don't think its normal, never had a car a with the rpm needle bouncing, I know some people and S.A would say" your car is sports, performance, space car"perfectly normal. don't buy it, I would think its normal for the rpm to drop a little or at least the idle to keep up, instead dropping to 600 rpms and making the car vibrate more then my Cayenne diesel, don't think that can be considered normal operation, I had auto zone again do a battery test and they told it can be a problem with my alternator, it wasn't keeping stable voltage, it was up and down and failed the test

 

How old is your current battery? What yr/mk is your vehicle?

 

14 Panamera 12k miles, two year old battery.

 

Depending on how many times it has drained and been recharged, it could be toast. Most of the symptoms you describe seem fairly normal to me on start up. Turning the steering wheel will suck power and cause idle to jump around a little. I really wouldn't listen to guys from Autozone or places like that with a 14 Panamera. You can get some weird CEL's going off when the battery gets too low also. I think you're fine.

 

ThunderRolls,

I don't think anyone gets those symptoms on start up, cars idle at a higher RPM when cold,
I know that power steering wheel does that and I think to compensate goes up, but not sure about dropping, especially as soon as I lift foot off brake pedal on stop light, I went to autozone its faster then Stealer..

can you please confirm if your needle also does this? e.g. turning steering wheel, pressing window switch up whit windows closed or lifting off foor from brake

 

Wish I could test it for you, but I'm away on business until next week. If no one else does it, I can do it then.

 

I tested it today. Pressing the window switch up with the windows closed caused a small fluctuation in the RPM needle, a little less than what the video showed. Turning the steering wheel might have moved it a bit as well, but not as much as the window did. No vibrations though.

 

Well, your video looks totally normal to me. Any operation of electrical equipment increases the load on the alternator and brings the entire electrical system up to power. It gets power from your engine, causing fluctuations in your RPM's as the computer adjusts for the increased load, e.g., turning the wheel activates the power steering pump, etc.

 

ThunderRoll, Thats not my complaint, as I stated before should be normall for RPM to go up a little bit to compensate, what I Dont think its normall is the the erratic idle and RPM dropping at 600 RPM everytime I touch a switch, move steering wheel or lift the brake, makes the car vibrate simce the RPM is going way down

 

My car has been in the shop for more then a week, I called today and I was told, that my charging system is fine, but the jump the needle was doing when reving up it could be from a bad tachometer, that they are going to test with a used car, switching tach's to check if that solves the problem, if not to contact the area Rep again.

I don't think this could be from a bad tach, I can listen to the note change on my engine everytime it bounces or when I'm driving I can feel some hesitation, I did explain to the S.A
Maybe a small vacuum leak and like always he guarantee the minimu leak it will be displayed with a CEL, also I told him that I still think about the charging system but again he told me that they tested it and its operating as it should.

Any comments on this

Thanks