What does it mean when in park the car has rough idle? and also what does it mean when rough idle when in drive?

 

Please help me

 

how many miles on your monte and what do you have a 3.5 flex fuel or 3.5/3.9 LT non flex? and what do you mean rough idle? has it just started doing this?

 

It has 33000 and its the 3.9 LT3. I just changed the 2 lower motor mounts from the dealer as it needed gthem thought the roughness would go away..... its not a hard rough idle its just u can really feel the car running

 

mine kinda has a loppy felling in park and while in drive, almost like it would cut out but it has been that way since I owned it. I would say it's normal, I hope...

 

What's a loppy feeling??? But yeah mine 2 but it also runs alil rough like I said u can really feel it running then sumtimes u can't......weird.......and when I inch up at a light I feel the car shake what's that?

 

loppy is a rough idle, not a very consistent idle, shake??? all I can say is my car does run a little rough, it may be with the variable valve timing of these cars, really not sure though.. read the below article, I hope it helps...

http://www.autoblog.com/2005/09/30/p...s-gms-3-9l-v6/

edit: great pic of the 3.9...

 

Yeah shake only when inching up foot off break and off gas.......mine runs the same way I guess its not a bad thing it runs rough

 

from what everyone says, it is a great motor, with very little mods available though! I did put a CAI on mine and the mpg has gone up a little (2-3 mpg)! and I also added new magnaflow mufflers and tips, but left the rest of the exhaust stock.

 

All we can do is hope the rough idle is normal lol I agree I love this car and the motor just wanna keep the car running for along time.......got any answers to the shake question? And u helped me before and like last gime I thank you for all your help