Piston Slap: Whom to Trust Whilst Getting In The Zone?

Sajeev Mehta
by Sajeev Mehta

TTAC Commentator John R writes:

HI MAN!

I just replaced the battery in my 07 Sonata sometime earlier this year and now it’s behaving like it needs another. I should probably mention that I’m running aftermarket HIDs (I know, I know). I know (now) when the right lamp starts to fade and change from blue to white or sometimes purple its time to change the battery, but its happening a lot sooner than last time. I got a good two years in between when I had the HIDs installed and the last time I changed the battery. Back then I thought it was bulbs but as soon as I replaced them it started doing it again. That’s when I replaced the battery. Now its happening again.

I don’t think the battery is the problem – its a Napa Legend (75 month) which I understand is more than decent. My questions are these: knowing that its probably the HID setup sucking up all the juice (which I think is happening) what do I need to cope? A new alternator? A new battery, but this time do use the auto-on feature for the headlights?

Sajeev answers:

Thanks for your letter. If the car starts and runs, the alternator is fine. Your only problem sounds like your shitty HIDs: you can have a parts store (like AutoZone) test the charging system for FREE to know for sure, but I bet I am right.

Lose those lights, they are just glare machines because you don’t have an HID headlight assembly to properly harness the beam generated from said bulb. They will blind you (more than normal) when you pass a reflective sign or when you drive in a thunderstorm at night on a well-lit road. That, and they are often unreliable junk from vendors who wouldn’t know quality control from a hole in the ground.

John R replies:

“Your only problem sounds like your shitty HIDs”? DAMN! Oh, well. Thanks, Sajeev. I’ll head to Autozone this week.

Shortly afterward, John R replies:

HI MAN!

I just got back from Autozone. Not only will they test the charging system for free, but they’ll also charge the battery for free. I wish that was my problem, though. The battery came out 100% and alternator checked out fine. However, (and I’m not too surprised) the starter failed one out of three times.

Not often, but every once in a while before this episode started I would get the little “RAT-TAT-TAT” sound while trying to turn over the engine.

Now they can test the starter by itself – you just gotta rip it out. I guess its time to break out ye old Haynes manual…

Sajeev answers:

Well, they test both systems, but I rarely note the distinction between charging and battery/electrical systems as they are so interconnected in modern cars. It’s truly amazing what oddball electrical faults will show up because of a bad wire in the charging system, a FUBAR’d alternator, or a weak battery.

So now you need new headlights AND a starter? Welcome to old car ownership: a poor initial diagnosis is like a kick in the crotch when you get that second opinion, no?

John R replies:

Well, hopefully just the starter. I’m going to take it out some time this weekend. Thanks for the AutoZone tip. At least I’ve got it narrowed down.

Sajeev answers:

Oops, I hate giving tips that make me sound like a shill. Because I only shill for Panther Love or anything Fox Body/E39/LSX-FTW. Probably.

I don’t buy remanufactured alternators/starters/etc from AutoZone anymore. But I did. I normally reference them because of their national name recognition (and I’m too lazy to make a roundabout generalization about free component testing when one word says it all) but many other parts places do the same free tests.

AutoZone was (is?) the worst (in terms of quality) for new or rebuilt components from no-name manufacturers. I’ve been burned too many times to trust them anymore. That said, maybe Autozone improved their quality in the past 5-10 years, maybe we should trust them…but now I buy new or “rebuilt with 100% new parts” from other vendors, as availability for my older hoopties dictate.

Best and Brightest, chime in on your favorite vendor. Being stranded in the rain and multiple tow bills from their lifetime alternators has royally ticked me off.

While I do like Autozone for many brand name parts, I lost my faith on the other stuff. Except their cheapo wiper blades, they work just fine and are, well cheap. Stick with brand name stuff, shop other parts stores for those “FML, I’ll never do that job again in my driveway” parts like a starter.

And did you go back to factory style lights from a decent vendor? I sure hope so.

Send your queries to sajeev@thetruthaboutcars.com . Spare no details and ask for a speedy resolution if you’re in a hurry.

Sajeev Mehta
Sajeev Mehta

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Comments
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  • Herm Herm on Jan 10, 2012

    What is the system voltage when the car is running?, it should be well over 12V. Try cleaning the alternator.. spray some engine cleaner Gunk on it, wait a few minutes and hose it off.. perhaps you have some oil residue built up in the brushes.

  • Daveainchina Daveainchina on Jan 10, 2012

    I'm not a fan of either Pep Boys or autozone. More than anything though, find a good parts man. A good parts man will know a lot about fixing a car and give great advice. My experience at Autozone and Pep Boys is in general people who have little experience fixing cars and they are more or less just clerks who can read a computer screen. A good parts guy will also give you some great suggestions on what to check what is wrong with your car and if it's not busy, he will come out into the lot and take a quick look at your vehicle with you. Find one of those and pay his prices for parts, you'll be happier because you spend much less time fixing the wrong things.

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