Ok, so when I turn the car on the rpms jump right to 1.5-1.9. They stay there for a little while even if I have the clutch all the way in. Now I know for a fact that before this when when i had the clutch all the way in it would drop the rpms down to 0, which it should. After o lets say about ten minutes the rpms drop to about .5. So i dont understand y all of a sudden this happened. Any help would be greatly appriciated. I was talking to a guy and he said the thermostat....but im guesing there could be more that 1 problem going on.

 

To address this problem, I would start by cleaning the IACV. You might also try to bleed the cooling system of possible trapped air.

I don't understand why you think the idle rpms should drop to 0 when you push in the clutch.

Is the engine also overheating? I don't think a bad thermostat would cause the abnormally high idle rpms.

 

well the rpms never b4 this situation where anything but at zero so idk

 

I'm not sure what year Civic you have, but the normal idle speed should be about 700 rpm without a load.

 

is your engine overheating? then you might have a blown head gasket.

and if your idling too much, it could be your throttle body is clogged up of too much carbon or dirt build up

 

i have a 99 ex coupe, nope not overheating because my temp gauge stays nice and low like normal, but for it to shoot up to almost 2k rpms and then chill there for a little while is completely unnormal, after awhile it drops to around 500 so i guesing its not a big deal but little things usually turn in big things so i want to get this fixed because it never did this before and plus im using more gas. THANK YOU GUYS FOR YOUR HELP

 

Ok well this problem has how escalated...I was driving today and when idling my rpms would jump from 1-1.5 It would just keep doing that over and over again. And finally a orange light went on in the dash board and said check i think. Well i think one of my hoses has a leak but im not sure which one i forgot the name of it. I can hear a hissing sound when the engine is in idle. I'm not sure where to start.

 

Try to precisely localize the hissing noise. Then, take a picture of the hissing component and post it in this thread.

Here's how to pull the CEL code:

http://www.honda-tech.com/zerothread/1901557

 

o vacuum hose!!!! I think thats the problem....would this cause the check engine light to go on and my idle problem, thanks for the code btw

 

Yep, vacuum or intake air leak is a textbook cause for idle problems. Still do pull the CEL code, as it will likely aid in fixing the problem.