Rough Idle and bad gas milage

[DiannaG]

I have a 2000 Grand Am GT. Great car, but seems I am getting poor gas mileage lately. I am not even getting 225 miles per tank. Also, when sitting at a light and in drive, it idles somewhat rough. If I shift to neutral, it's just fine. One more thing.......is it normal for the car temperature gauge to go above 200 if sitting in idle for a minute or so? This tends to bother me. Someone told me the Grand Am runs a little hot, it that true? I have plenty of coolant.

[GTP Dad]

Several items, first to cure the idle problem clean the idle air control motor located on the throttle body. This controls your idle speed and it is probably dirty from use. Simple to clean with throttle body cleaner, just remove, clean allow to dry and replace. One tip, when you have it out don't move the pintle is screws thing up. As for the fuel mileage you may need a tune up, plugs and wires. The other thing is to replace the O2 sensors as they control how much fuel go into the engine. If they are original and you have high mileage then they are probably due for replacement anyway.

The heat issue is probably normal especially if the AC is off. The cooling fans run on high when the AC is on but do not turn on until around 210 degrees when under normal driving conditions.