Need help 97 SC2 low idle hesitation

[lazyman73]

I just purchased this 97 SC2, 136,000 miles on it and it has a slight problem. Typical day driving: When car is cold not a problem with any acceleration or shifting hesitations. When the car warms up about 10-15 minutes later, shifting is no problem but there is a slight hesitation in all gears when the idle drops between 1800-2400 rpm. After it gets past the hesitation point the car runs strong until I shift. Another food for thought is that if I keep my foot down on the accelerator when shifting the car runs throught the gears without a single bit of hesitation. This car has me stumped and need some guru about saturns to help me finger this one out.

[ssicarman]

Have you checked the ignition system? Plugs, coils, wires? coolant sensor?

[lazyman73]

What would the coolant sensor have to do with this problem. As for the ignition system it is all new.

[ssicarman]

It is actually amazing how many things a bad temp sensor will affect. I have test driven enough S-series cars that I am to the point that I can very often pick up a bad sensor just on how the car drives. How the RPM's change or if there is a bit of a hesitation. Not saying that your sensor is bad for sure but it is worth checking out. Pull it out quickly and inspect the tip to see if it is the plastic one and if it has any cracks. Relieve the cooling system pressure by removing the rad cap. Put the cap back on and then remove the sensor. You will have minimal coolant loss. The coolnat will slowly gurgle out.