Hopefully someone out there can help me out. I havea 2001 SC2 with 53K, original owner. Great car! Last year was the first time I have had a problem with it. The valve body in the automatic transmission went bad, but according to these forums, that isn't new news! Still it's a great car. It starts up every time and runs strong. Here is the symptom: The car starts, runs, and idlesnormal. As soon as I put it in gear, it jumps up to 2000 rpm and tries to stay there but the transmission holds it back to about 1100 to 1200 rpm. I approach the speed of light when I let off the brakeat 25 mph without ever touching the gas. While coasting, I will pop it in neutral and watch the RPMs go to 2K. When I stop and put it in park, it drops back down to 800 to 900 rpm (normal). No code lights and no out of the ordinary sound. Any ideas? All helpis greatly appreciated. Thanks!

 

1-Check your engine coolant temperature sensor; the original one is resin tipped and prone to cracking wreaking havoc with engine running/transmission problems, while the replacement one is brass and inexpensive. Closely examine the connector for corrosion and replace it of necessary. This coolant sensor should be a priority before performing any other maintenance.


2-Check around the throttle body and clean with carb cleaner inside and outside including the linkages. Be sure to check the idle air control valve on the side of the throttle body; don't allow carb cleaner inside this IACV as it is a precision servo motor that controls the idle speed. Remove it if the throttle body is dirty and clean each unit separately.

 

I disconnected the IACV and the idle problem went away. Does that mean this is the problem?

 

Not likely as the crucial item needed to control and adjust idling is the idle air control valve (IACV). Disconnecting it won't solve the problem as you haven't responded to the suggestionsI posted. The role of the IACV is to control idle speed when the a/c is used and when decelerating from speed with the throttle closed for emissions purposes. Leavinthe IACV disconnected is a short term band aid from the real issues that haven't been addresed.

 

Where exactly is the coolant sensor located, and is it something I can find in the local auto parts store? The nearest Saturn dealership is over 380 miles away. Alaska isn't exactly convenient. I really appreciate your help ducky.

 

Ok, didn't know where you were located and Alaska is a bit way off the nearest Saturn dealer so you can buy it online from places like http://rockauto.com, http://saturnparts.comor similar places. Here's some pictures to locate the coolant sensor, http://www.saturnfans.com/forums/showthread.php?t=37884. Hope this helps. And yes, you can most likely find the coolant sensor as long as you can buy the equivalent part in brass only, no plastic as the original. Its a low cost part, something like $10 or so.

 

THANK YOU DUCKY!


That post in the other forum was extremely helpful... I work two jobs and haven't had time to just stand there with my head under the hood to figure it out...

 

Thanks ducky! I will try to take care of this this weekend when I get a chance. You are a great help! By the way,I forgot to mention the symptoms are not always present. Today there were no problems at all and I haven'tdone anything yet........I guess I can look at it like this.......If it ain't broken, fix it til it is! LOL