What are some signs of alternator going bad?? My car has 105000 km, and i notice whenever i start my car when is warm, it idles very low (below 500 rpm, when i put it in reverse/drive, it sounds like it wants to die out).... it happens only when i drive the car until is well warmed up, shut it off, and start again..... (i guess when the car is cold, the computer will automatically rev the engine high to warm it up) i have tried changing plugs (helped a bit), plug wires, clean IAC valve, clean throttle body, etc.. but nothing really seems to cure this problem.. my next guess is the alternator........

 

I have had lots of alternators go out, and whenever they did, they just died and so did my car. I've never experienced one that's in the process of dying and fluctuating like that. An option you have, however, is to take the alternator out and take it to the nearest Checker or Autozone (in another car, preferably, unless you want to walk most of the way). They will test it for free and that will tell you if it's time to replace or keep looking for the problem. Although I don't think that's your problem....did you experiment with your idle control valve at all, or just clean it? Also I would check for vacuum leaks...

 

yea, i only cleaned the IAC valve, didn't really experiment it, but because it only happens during time when the car starts AFTER its been driven for awhile (normal operating temperature), i sorta ruled that out... any other time, the car idles well.... (though its been a bit noisier)...

i was leaning toward the alternator because i notice my dash lights were a bit dimmer then what it use to be.... i replaced my battery 3 months ago so its not the battery... i never had a bad alternator before, so i don't know what the sypmtoms are... thanks for the input Tomservo