I have an 04 SS Monte Carlo with the 3.8L Supercharged engine. It's recently developed a problem I'm hoping you guys might be able to help with.

The Check Engine light is on and it stumbles then surges a few times intermittently on start-up and sometimes at idle. Also, when I remove the gas cap with the engine running it will go into a cycle of stumbling-surging-stumbling-surging sometimes to the point of dying and smells strongly of sulfur.

It was doing this a few months ago and I just took it to the dealership. They replaced the gas cap & the problem went away just long enough for my extended warranty to lapse so now it looks like I'm going to have to try fixing it myself.

I took it to Auto Zone & they pulled a single DTC of P0496. From what I can find online, I think this means the Purge Solenoid Valve is sticking. I found step-by-step instructions here for diagnosing the same code on an 07 Sunfire. Am I correct in assuming this would be the same for my Monte? If so, most likely simply replacing the Purge Solenoid Valve would fix the issue, right? Also, would someone please provide me with a picture, drawing and/or location for the Purge Solenoid Valve, I'm a little lost as to where it is and how to identify it?

ANY help is appreciated!

 

Have you seen about the Cat? The smell pf sulfur makes me think that maybe its clogged.

 

It's brand new & I only smell it when it starts stumbling. I'm sure the sulfur smell is a byproduct of the ECM trying to keep the engine running by auto correcting the stumbles. It's flooding the system & the unburned fuel is hitting the cat.

 

Wow, I really thought this was the place to go for tech questions on Monte's. I appreciate Popcorn King's input, but that doesn't address any of my questions. Doesn't anybody know???

 

Sounds like the purge valve is stuck open. Its suppose to be closed unless activated and the vent is always open unless activated. So if the purge is stuck open with the vent open, it creates a vacuum leak, which explains the running problems. Opening the gas cap creates an even bigger vacuum leak which makes it run worse.

Also, having the purge open all the time will cause the engine to draw in fuel vapor when its not suppose to, causing the engine to run rich, which makes your converter work harder and produce the sulfur smell.

I would replace the purge. Its a 5 minute job. Remove the engine cover. It should be mounted above the back valve cover. The should be 2 hoses going to it and an electrical connector. When you remove it, blow into it, if you can blow straight through its no good. If you can't, I would replace it anyways because it can stick open intermittently.


Its number 2 in the picture here. Its says Bonneville but its in the same spot on the monte. Looks like its pretty cheap too
http://www.gmpartsgiant.com/componen...7mn72hx69.html

 

That's exactly what I was looking for! Thanks labnjab!

 

Ok, it's got a new purge solenoid and it appears to be fixed. yippee!

Finding the part from AutoZone was fun. They don't list the part in their computer, so when you call they will tell you they don't have it. I knew they did though because O'Reilly and Pep Boys both do. They listed it at $35 & $42. I ended up taking the actual part off and handing it to the AutoZone manager. It has Delphi and the number 1997278 molded on it. He cross referenced that number to their Duralast part number PV146. It's exactly the same part, it even has Delphi & the same number molded on it. And it was only $22! Here's a link: http://www.autozone.com/autozone/par...artNumber=true

Thanks again for your help!

 

Glad you got it fixed man.

 

Bumping this old post because I had the same problem yesterday and I took some pictures while fixing it this morning. I'll just upload the before and after, it literally took about 15 minutes to fix. Thanks to labnjab for mentioning to blow through it to see if its bad...mine you could blow through so it made it easy to figure out what was wrong.

I paid $33 from advanced auto for the purge valve solenoid

Dorman Part # 911035

Before

sNR8lhd.jpg

After

G00nu2A.jpg

Pretty easy fix, I chose to upload some images here regarding this issue because I was unable to find any myself on the internet hope it helps somebody someday!

 

Follow this link and read posts number 51, 53 and 56.
I hope it helps anyone with an emissions evap code.
I found and fixed mine. The lady I bought the car from said the light had been on for years. She just ignored it.
MM
https://montecarloforum.com/forum/mo...e-23231/page6/