[ChicagoGirl96M]

Hi Guys, my little Leo is misbehaving again....

Got in the car this morning, and my battery light was on. It faded in and out as I drove to work, coming on strong at stoplights and under heavy acceleration (4000+ RPMs). Along with that, there's a whine to the engine that wasn't there before.

When I put the car back together last weekend, I checked the battery. 12.29 volts off, so it should be fine, right? However, I don't know how much wiggle is okay with the battery terminals. I couldn't get the negative one to tighten at all until I got a new bolt for the thing-the old one was stripped. But I can still move both connectors with just a little effort. They're not about to pop off, but they're not tight enough to be immovable.

Any thoughts? Do I need to replace the connectors? Is the whine associated with the battery light? Could this be why my check engine light came back on? Should I bite the bullet and take Leo to a mechanic and have them do a complete inspection of the car to see what the original owner didn't take care of? Sorry for all the questions-this is my first used car and I'm new to do-it-yourself car care!

 

[ShadowSE95]

you shouldn't have any looseness in the connectors. tighten them up snugly and make sure they were clean (the battery posts and the connection terminals) before you put them back on. also check all the grounds around there to make sure that they are clean and grounded solidly. if that dosen't work, try taking the car to an autozone where they will run a test on the battery and alternator and make sure that they are both in good working condition. (its free, just go inside and tell them that you need it done)

hope that helps.

 

[Guy2626c]

a whine like your describing, sounds like an alternator. Yes you should fix those posts. I had to replace my contacts the metal was cracked. It's not hard i was able to chop off the old one and put the new one right on. If your battery has ANY corrosion on the termanials you should get a wire brush and scrape it off. Another thing that i was told that helps avoid corrosion is to put a little vasaline on the termanial before you put the connector on. I did not do this as i was told about it after i did the work. But the loose contacts are bad, they caused me many headaces when the neg. wouldn't contact great and it wouldn't start untill i wiggled the connector. Save yourself the headace and not only replace the connectors but check the alternator.

-Sorry about the long reply.

 

[Aussomea]

autozone requires the alternator be off the car to test it and its a bitch to get off. also autozone sells dielectrode grease to prevent corosion. u should be able to hit the battery cable connector with a wrench or something to snug it down onto the post, dont hit the post tho.

that whine and light does sound like ur alternator... stage36 had a good idea a while back about checking where the noise is coming from. cut off a length of hose, hold one end to ur ear and use the other end like a stethascope to narrow down where the noise is coming from. if uve got friends at an autoparts shop a new alternator will be $90 otherwise its $180 just for the part. then if u knew what you were doing it'd probally take u at least 2-3 hrs. i had to do it a couple months ago and it took me like 8 but that was partially due to the fact that i was doing all the work at night and i couldnt see anything.

 

[ShadowSE95]

autozone requires the alternator be off the car to test it

no they don't. they can do it both ways. just go ask. trust me.

 

[ChicagoGirl96M]

<sigh> Okay here's the deal with the car.

Went to Autozone after work yesterday, and when they hooked up to my car the battery and alternator tested out fine. Then they linked up to check the error codes, and there are three:

P0100 - Mass or volume air flow circuit malfunction
P0110 - Intake air temperature circuit malfunction
P0400 - EGR flow malfunction

I'm still working on interpreting those codes from my shop manual. In the meantime, can anyone help explain them in plain English?? I haven't figured out exactly where the malfunctioning circuits are, although I'm hoping those aren't difficult to replace. The EGR thing I'm ticked about, since just last weekend I had the throttle body off, and it would have been a lot easier to get to the EGR valve then. But I've replaced the solenoids that are related to the EGR system-does that mean I probably need to replace the valve?

 

[imezru]

When they tested the alternator how many volts was it putting out? If it was high like 16 or 19 or maybe even higher it would be from the loose connections. I had loose connections on mine. The bottom lip on the negative connection was cracked. I quick simple fix is to put the connection on upside down. Therefore the preasure to get the connection tight is not where the crack is. Did this two years ago and have not had any more problems. Hope it helps.

mike

 

[ShadowSE95]

P0100 - Mass or volume air flow circuit malfunction
P0110 - Intake air temperature circuit malfunction
P0400 - EGR flow malfunction

i can't see how these would cause this "whine" you were talking about or a battery light

try spraying the belts with belt dressing and hitting the pullies with some wd40... i wish you could take off the belts and spin the pullies by hand to see if you are getting the whining noise, but that is just a big PITA... the only thing you can do is turn on the car and listen.

 

[Rat]

I'll bet that you have a blown diode in yer alternator. Symptoms of a blown diode include a whining noise and lower-than-normal output at low engine RPMs. As I recall, the on-car alternator test is done at something like 2000RPM, which should be high enough to mask a blown diode, I think. An alternator test would find a bad diode, but you would have to take yer alternator off the car so they could put it on their test rig. I dunno how hard it is to get the alternator off an MX-6, but I really think that this is probably yer problem with the charging circuit. The fact that alternator output is only inadequate at low speeds could also explain why the battery light faded in and out. As fer the other codes...I dunno bout those. It is POSSIBLE that if yer alternator isn't putting out adequate voltage, then it MIGHT be fouling up voltage signals to some of yer sensors, but that is little more than irresponsible speculation on my part. Yank that alternator and get it checked out.

 

[CRiZO]

I think this should be a sticky or something, answered a lot of my questions as well that I didn't get in the electronics forum.

 

[Methman]

Autozone had to of made a mistake, or didn't actually do an output test on the alnator, because the whinning noise and the batt. light comming on and off is deffintally a bad alnator not producing enough voltage, becaust the Batt. light is designed to come on when the cars voltage reaches below a cirtin voltage. I would get the alnator replaced, And I don't know if there is one on the MX-6 or not but I would also replace the voltage regulator also. (that is if there is one)

Methman

 

[ChicagoGirl96M]

Thanks for the advice, guys. It did turn out to be the alternator, and just my luck, the bad alternator killed my battery too. At the end of today I'll get to trade $600 for my car. Just figures this had to happen when I didn't have the time to do the work myself and save some money!