Hi Im new to this forum and this is my first monte. I have had trucks and jeeps all my life and have no idea how to work on this infamous 3.4 DOHC. I bought this car as a project for cheap so i know there is probibly a lot wrong with it.

First I need to get this idle problem solved. When I start the motor up it revs up to 3000 rpm then it drops to under 1000 then back up to about 2000 then down to under 1000 then back up and repeats. The car drives fine and seems to have a lot of power but even when its warm it still has that idle problem. I also noticed when its hot, oil bubbles out of the sparkplug holes. I am going to replace the valve cover gasket and the front 3 plugs to see if it makes a difference.

Im also going to check for vaccume leaks in the intake

Any other ideas why the idle purges????

THANKS!!!!

 

is the CHECK or SERVICE ENGINE light on?

 

2 cheep things that might help: get a new TPS (throttle position sensor), they are a sub $15 part, get a new EGR valve ($3) and finally try soaking your MAF (mass air flow) sensor with brakecleen.... if it is caked with crap, you can clean it & idle should improve some.....

 

Could also be anything filter related / plugs related (tune-up)

or your IAT sensor or a PCV valve.

 

I would start with your idle air control valve on the throttle body. Unplug it and if the car stumbles and stalls, then it is fine, but if there is no change when you unplug it, then it is probably bad.

 

I replaced the "cam cover gasket" and the 3 front plugs. It seems to run a little better but still not good by any means. Today after i replaced those parts i started it for the first time in 2 days and the rpms went to 3000 then it stalled out, it did that twice until it actually stayed "running." I could not detect any vacuum leaks. Does anyone know if this car has a coolant temp sensor, if that might be a problem, and where is it located. thanks a lot.

Also the SES light is not on, its hard to believe it even works scene this car is running so poorly.

 

OHH and when I give it gas when it is running the rpms SLOWLY fall. for example if i rev it up to say 4,000rpms it will take about 4 complete seconds for them to come back down to 800-1000rpms
I love this car but it sure can be a headache sometimes, thanks

 

I hope it's not what I went thru:
https://montecarloforum.com/forum/sh...light=jogasz28
Bad factory intake plenum gaskets...and several while-you're-in-there things to do.
But...after all the work I did, and a coil pak that just went bad Friday, it really runs strong.

 

well imma be honest my monte with its 3.1 has been having a similar problem.... i would see if you can get a firend to scan it, but when i had mine done yesterday i found out my upstreem O2 sensor is bad, which is causing the car to run lean, which is causing another code, & more chain reaction BS... i got a quote from national auto for 52.00 for a new one... i will let you know what happens when i replace it, 'caus it sounds like the same problem you are haveing...

 

Have you done anything we have suggested you to do? Usually thats what you do when you ask someone to help solve your problem. If not you are just wasting peoples time. The cam cover gasket will not effect idle and spark plugs do not cause problems like you have.