I have a 2000 SL2 that gets stuck at high idle. I'll pull up to a stop light and the engine will stay at 2000+ RPM, sometimes even up to 3000 RPM. Interestingly, if I shut the car off and immediately restart it, the idle will drop down to just below 1000 RPM, just where it should be.

We have also had a constant SES light for a long time, so I took it into a Saturn dealer. At a cost of $750, they replaced a temperature sensor, an oxygen sensor, and a thermostat. Now I still have the problem and the engine is running hotter than it did before.

What the heck? Any idea what else this could be? I don't have enough money to just keep replacing parts until something works. I'm pretty irritated that they didn't fix it yesterday.

Thanks
John

I would bring the car back to the Saturn dealer and explain that the problem persists and see what they have to say. It sounds like alot of money to replace a coolant temperature sensor with the dealer wiring harness/upstream oxygen sensor and thermostat. It could be as simple as a gummed up butterfly in your throttle body or a faulty EGR valve. Again, I woud start with the dealer since you paid money to fix a problem, that still exists.

I just did a little more reading and found another forum where someone said that if the problem goes away after restarting the engine then it's likely a throttle position sensor. What do you think?

Thanks!
John

Do you have a scan tool to properly look at PCM data? If so you can scan it for any codes, and you can look at the data from the PCM - that will let you know if you have any issues with a TPS. If you have codes, please post them.


Eric

They found out what the problem was. They said that they had cleaned the throttle body yesterday, but something in there was still clogged by a small chunk of carbon. They cleaned it again and now all is well.

There are posts that deal with cleaning the throttle body. The more information you learn about your car, the less expensive it will be to perform routine maintenance. Going to a dealer is expensive to say the least. I have gone to the Saturn dealer twice since I have owned my car. I bought it new 10 years ago. Each time the estimate for repairs topped $1,000. Did the work myself for less than 20% of the first estimate and 3% of the secound estimate. The only work that I would have a dealer perform at this point would be diagnostics and only if I could not read a code or trace down the information I need to find the cause of the problem. This web site is performing an invaluable service to those who want to learn and are interested in performing their own repairs.

my car did the same and its a 96 sl2 so i unhooked the battery