Cavalier high rpm while moving


#1

The car idles while moving,between 2k and 3k rpm at any speed until like 60 mph but goes back to normal after the car stops. We replaced the iac and the tps and don’t know what it is.any help would be appreciated.


#2

Is this an automatic? If so it may be that your lock-up torque converter is not engaging.

One thing I’m not clear on. What happens above 60 MPH? You said it happens until 60 MPH.


#3

It’s a standard. Sorry I meant to put the engine light comes off and the rpm’s go back to normal but when we start to slow down the rpm’s go back up until we stop.


#4

And we are not on the gas


#5

“Sorry I meant to put the engine light comes off and the rpm’s go back to normal but when we start to slow down the rpm’s go back up until we stop.”

can you elaborate on this, I can’t make sense out of it.


#6

“I meant to put the engine light comes off”

If I am interpreting that correctly, then I am guessing that the Check Engine Light is lit up when the engine is revving very high. If that is the case, then there should be Diagnostic Trouble Codes (DTCs) that have been stored by the car’s OBD system.

Go to an auto parts retailer for a (usually) free reading of those codes, and then come back to this thread to report the exact codes, which will be in a format similar to P0123. That would be the best place to start for a diagnosis.


#7

Unusual increases in rpm while driving without a corresponding change in vehicle speed could indicate a slipping clutch. Best idea to begin is what @VDCdriver says, have the diagnostic codes read out.


#8

We checked under the hood and it was three vacuum lines disconnected from the throttle body. They just popped out but don’t know how they did that, they have been connected the whole time we had the car.


#9

@kbd15100

“three vacuum lines disconnected from the throttle body.”

Considering the Cavalier has been out of production for awhile, those vacuum lines might have fallen off, because they’re old and rotten