So I was talking on the phone with my dad about my alternator whine and the problems with my car. He told me to try and start the car, let it run for about 10 minutes, then take the positive cable off of my battery to test if the alternator is holding charge. I did, and it seemed to run fine without the positive cable on, but when I opened the door, the interior light was flickering bad and as soon as I tried to turn on the headlights the whole car died. He told me it seems my alternator is going bad...just wanted to know what you guys think.

Thanks.

 

take it to autozone... they can test your alternator when the car is running. I don't think it is a good idea to pull the cable off the battery while it is running.

 

They told me I had to take it off...which I don't mind doing as long as I am more sure that I will actually need to replace it than not.

 

thats weird... last time i was at autozone they hooked up their tester to my battery and had me start my car and checked my alternator that way...

 

It is BEST to test it OFF the vehicle, but some stores have tools to check them on the car... not as accurate, but it can tell you something.

I don't think that necessarily means that alternator is bad.


What problems is it having under normal driving (besides alternator whine)?

 

drive normally with everything on... stay at a stop and see if the car surges or jerks forward a bit then try the turn signal if the lights flicker a lot then its the alternator.

 

i have a low/rough idle that seems to jump around a lot, especially with the AC on, but it does happen with it off too. I'm going to take it off tomorrow and take it to autozone, it shouldn't take long since its only 2 bolts and its right on top. I will get them to test it before I make my decision to purchase a new one. I'm really just trying to narrow my idle/CEL problem down here. I know a bad alternator can't cause a CEL but i figured it could possible cause the crazy idle.

 

whats the cel code?

 

I'm getting P0441,P0442, and P0446 accompanied by a ____ty idle, especially with the A/C on. Replaced spark plugs, oil, new pcv valve, cleaned MAF sensor and throttle body and put a new gas cap on. I also took the alternator off and advanced autoparts told me its fine.

I'll have to wait about 150 miles before the CEL comes back on, but it currently still idles like crap...dropping to 400 at times.

 

how many miles does the car have? if its around 60K or more it might be the coils. also check the coolant for a charge, that can give you a misfire and/or misfire code.

 

i just ran those codes its a vacuum leak. take carb cleaner, wd40 or windex and spray ur hoses, if the idle changes you found a leak. also check for any hanging hoses on the firewall sometimes they have vacuum blocks and they get loose.

if you dont find anything it might be ur evap canister, egr or idle control valve is bad more the latter. but try the cheap stuff first.

 

The car has 71k on it. I checked all the vacuume hoses as best I can, tried the carb cleaner trick, and even checked the evap lines under the car...I can see no problem.

I was thinking possibly the idle air control, but I've had that whole part replaced two years ago and then, it was giving me a code specific to the IAC.

I have reset the code about three times, and the CEL comes on at 150 miles or very close to 150 miles every single time. I'm stumped and frustrated...it still idles crappy but I covered it up (for now) by adjusting the idle screw. The idle is higher now but its still more rough than I'm used to.

 

did you check evap canisters?

 

Iike the charcoal canister? I looked at it and as best I can tell its fine, but its covererd in a plastic shell and I can't really see the top of it. Its obvious that it hasn't been hit by any road debris though.

 

evap canister, evap solenoid (usually on the firewall), you might have another one under the gas tank i've seen a few cars have one down there including one two of mine.

 

Hey. So I looked at some of your symptoms of your car. Noticed a few that you had were some of the ones I was having recently. I found that the positive cable that goes from the positive terminal on the battery to the fuze box had some how broken off and thus wasnt making a clean connection. My car would idle weird once I had taken the main terminal off and then back on but I was told that was fine due to the car fine tuning itself again since it had lost all power.

I too had autozone check my alternator and from what I was told they dont check your alternator when they hook it up to your battery. They are just checking to see if your getting a charge. In order for the alternator to be tested it would have to be pulled out of the car. If i'm wrong then I do apologize but thats what I was told.

Sorry I cant be of more help.

 

Well, I checked the positive wire and it all seems fine. The idle is getting worse and lower by the day so I caved in and made an apt with the dealer. I have an extended warranty that I purchased when I bought the car so I'm hoping that will cover it, if they don't give me abunch of bs...

The apt is on Friday, ill be sure to post back when I find out the news. Thanks guys.

 

Well, I dropped it off at the dealer last night and they called me back this morning. They said they reset the light, and did a smoke test on the whole evap system, and tested both gas caps (my old factory one, and my new one) and they could find no problem. They told me the idle problem was just (normal for a 4 cylinder) ...I knew they'd give me that bull____. There is a noticable difference from the normal 600/700 idle I used to get and the sometimes 400-ready to stall I get now.

They told me to come pick up the car and take it back to them if the light comes back on...which it will.

We'll see.

 

Just an update. After that first time taking it to the dealer, just as I suspected, the CEL came back on about 50 miles into driving it. I took it BACK to the dealer over the weekend and they called me and told me I need: Idle Air Control Valve, Charcoal Canister, and Fuel Sending Unit. I asked them if it was covered under my 100k extended warranty and they said they'd check and have an answer for me by the time I got up there to pick up the car (because they had to order parts) When I got up there, they said the warranty company (fidelity, which they said was owned by Toyota anyways) approved the parts and they were on order.

A week and a half later I get a call saying all my parts where in, so I took it up there this weekend. Just picked the car up, they initially tried to charge me $795 for the repairs but I had to explain to the manager that I had 2 techs tell me it would be covered, so they charged me $0 total. The idle seems fine now, and we'll see about the CEL. But I did look and there is a brand new IACV and Charcoal Canister on the car...so far so good.

 

if you're still wondering how to check a good alternator. The easy way is to start the car and take a screw driver and see if its magnetized to the alternator. or take a voltmeter put the negative to a ground and with the positive terminal, place that on on the positive wire going to the alternator. You should get a reading of 13-14 volts. anything less and the battery isn't getting charged enough