tracker_57
New member
94 century with 3.1 motor. 90,000 miles. Recently started experiencing what I believe may be several different issues. Hopefully someone knowledgeable with this vehicle can shed some light on the problem. car idles fine until motor warms up. Then the fun begins. It is most noticeable when you put the car into park or neutral. The motor will start idling up and down irratically by itself. It will sometimes go up (what sounds like) pretty high. At times it does it when in gear also. I know this because when stopped at a red light, when you release the brakes the car will get up to 15-20 mph just on idle speed! Could this be the idle air control valve is bad? Second issue is that the check engine light flashes on and off at different times. Perhaps due to the sensor I mentioned before? Third issue is that the temp. gauge fluctuates alot more than I'm used to seeing. When going up hill, it creeps up towards hot, but then starts to come back down when fan comes on. When going downhill, temp gauge remains in normal range or sometimes a little below. Could this be the coolant temp. sensor? I had the car at a mechanic for a week and all he could tell me was that when he let the car idle (for 2 hours!!) he didn't see a problem with the temp. gauge, the check engine light never came on, and the idle speed seemed to him to be a little too low. I can't say that I trust his opinion since as soon as I pulled it out of his lot it began again with all said problems. I have tried (for check engine light) taking it to all the auto parts stores around (advance, autozone, etc.) and they all tell me that they don't have the OBD I machine needed to do a diagnostic on this year of car. If anyone can shed some light on these three issues, I would greatly appreciate it.