loping idle?

alero_bmxer · 10-26-2009, 11:01 PM

the past few months i have noticed when the car is warm and in park it has a lope to it. when i put it in drive and the rpm's drop the loping goes away. there is no miss or studder when driving or any sign of hesitation. any one else have this problem? also i have a WAI and dynomax muffler if that helps with any diagnosis.

[ion] C2 · 10-26-2009, 11:03 PM

Yup, but I have mild cams. Sounds cool.

If it's seriously bouncing up and down (RPMs), check out the IAC.

alero_bmxer · 10-26-2009, 11:07 PM

there is no bouncing of the rpm's but you can definately notice it when your standing behind the car and you can kind of hear it inside the car. dumb question but where is the IAC located at?

Malibu369258 · 10-26-2009, 11:18 PM

My Malibu's 3100 does that, but the rpm's don't move while idling, sounds awesome though. I have 2.5" exhaust and CAI on mine.

Ttop191 · 10-26-2009, 11:18 PM

/\/\ been having this same problem since i got my ho, only when warm and in park, im 100% stock so i don't think its your intake, only difference is with mine, normal idle is 750, but every pop, it drops to 500 for a milisecond, then gos right back to 750

alero_bmxer · 10-26-2009, 11:23 PM

i should add that sometimes while at stop and still in drive it feels like the car is lurching back and forth but again there is no visible change in rmp's. any help is appreciated. its annoying the shit out of me

[ion] C2 · 10-26-2009, 11:31 PM

Quote:

Originally Posted by Ttop191

/\/\ been having this same problem since i got my ho, only when warm and in park, im 100% stock so i don't think its your intake, only difference is with mine, normal idle is 750, but every pop, it drops to 500 for a milisecond, then gos right back to 750

vacuum leak

Ttop191 · 10-26-2009, 11:33 PM

And what do i do to fix this?
Btw sorry bmxer for stealing this

[ion] C2 · 10-26-2009, 11:34 PM

Spray carb cleaner around the engine while it's running and see if you notice a change in idle. If there's leaks it'll get sucked in and burned and it'll change the sound of the engine. Otherwise you could hook up a pressure tester and listen for air hissing out with the engine off.

whiterider00 · 10-27-2009, 01:56 AM

Quote:

Originally Posted by alero_bmxer

i should add that sometimes while at stop and still in drive it feels like the car is lurching back and forth but again there is no visible change in rmp's. any help is appreciated. its annoying the shit out of me

i used to have the exact same issue. if ur sitting there at a light or something, it would kinda very lightly pulse back and forth, almost like youre lightly hitting the gas a couple times every second right? i never saw a change in rpms either. once weather warmed up this past spring, it was gone, as well as a noise it was making at the same pace as the pulsing. so unfortunately i dont know what the issue is, but i did drive that way for over a year and nothing negative happened to the car. good luck, and if you figure it out let us know.

Blktrax · 10-28-2009, 12:47 PM

If yours is the model with EGR, I'd look to the Valve being slow to react or the passesges getting built up with carbon. Not enought to set a light but enough to make a diffrence. The valve doesnt react instantly; But thats where I'd look.

Only other thing I can think of is the Chain tensioner wearing down combined with chain strech. So at idle its slightly out of time.

alero_bmxer · 10-29-2009, 10:48 PM

okay i know what it is and what it does but where is the egr valve at on the 2.4? and what can i clean it with?

Blktrax · 10-31-2009, 03:28 PM

If you have it it should be right next to the powersteering tank ,to the left of and forward closer to the radiator . Basicly you have to use a peice of wire and a drill and use it like a drain snake to break the carbon loose.