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Your high idle is most likely a vacuum leak. I've had a few with leaking intake gaskets around number one cylinder. Check all vacuum lines for splits or breaks. You can spray some carb cleaner around the throttle body to manifold mating surface and the intake manifold to head and listen for the rpms of the engine to change. Be careful around the exhaust manifold when you are using the cleaner. The electric items on the throttle body are the IAC valve and the throttle position sensor. The IAC valve can create idle problems but not usually this high. 3000rpm is a good sign of vacuum leaking.
Let me know if you need anything else.
Ok. That does change things. Stay on, I'll will be right with you.
Do you have access to a scan tool that can read datastream from the PCM?
Idle is PCM controlled by various sensor inputs. Saturn had a problem with coolant temp sensors that where cracking , leaking and /or had corroded terminals. Unplug your coolant temp sensor and check the terminals for corrosion , check for wetness inside and look at the plug for corrosion. If any wetness or corrosion is found, replace the coolant temp sensor.
The other area to check requires a scan tool to allow you to adjust idle manually through the IAC to determine if the IAC is working properly. Coolant temp sensor can be checked to see if it is reading properly with the scan tool.
Have you had a check engine light and if so, what were the codes? This will help further for either you to fix or if needed, have your tech fix.
Get back to me with the engine and model and we can get further into what to check. SL1/SL2.
In the end. If it's not vacuum which from your description, it isn't. It lies between the IAC or temp sensor. Temp sensor will create erritic idle.
The more information you can give me, the quicker we can get an answer.Meawhile, try checking that temp senor as described. It is on the trans side of the engine.
Ok whitey. I'll watch for your response.
It's on the rear of the cylinder head right below the thermostat housing.
Here is a better pic of component locations. It's for a 2000 but is the same as 99. 2000 just has a better reference picture for some reason.
Sorry. Forgot to add pic.
Here you go