I have noticed this many many times but cant explain it! I will just be cruising (normal driving) and I'll stop at a light and out of nowhere it will sound like someone is knocking 3-4 times on the back glass. Now, I know its not someone knocking cause I look up when i hear it and nobody's around. Obviously its got to be something in the back of the car. Evap Canister?? Fuel pump?? What do you guys think it could be??

 

Get it used? Someone died in your car and now you have a ghost?

 

Google = trunk monkey cobalt ss.
U are not the only one

 

Just one of the pages they talk about this. https://www.cobaltss.net/forums/gene...king-sp-79377/

 

lmao!! actually I traded a beat up truck for this car cause it had a blown 2.4 engine and I dropped a LSJ in it and a bunch of bolt ons. I thought I was crazy for the longest time cause i kept hearing it and no explanations. Does anyone know what it could be?

 

Evap vent valve by gas tank.

 

Thanks for the link! It's the evap system purge canister. There is a TSB out telling the dealers not to replace it as it's not malfunctioing.

Sounds like someone knocking 3 times on the trunk.

I'm GLAD it wasnt someone locked in my trunk HAHA even more happy it wasnt me going crazy!!

 

Mine does it 5 times I believe lol

 

ya, i think mine is sometimes 3 times and sometimes 4 times but it doesnt do it that i know of every trip. Most of the time I have my radio on or sometimes I am talking on the phone but when I'm not doing those things lol I still dont hear it every trip. It might be different for me, I never thought to see if the 2.4 na and 2.0 LSJ had the same fuel pumps and/or EVAP systems cause it ran after the swap and it ran good with no problems lol maybe I should look into that haha

 

I disabled all my evap ****

 

MR.B!!! now we have some knowledge in here! Why did you disable the EVAP system? Is there any gains to doing that? can you disable it with hptuners or is there another method?

 

My Evap system is partially gone now as well. Broke the nipple on the solenoid or whatever is under the hood a couple months ago so I just deleted it Have only driven it twice since then though so I dont know if it still does it or not.

 

Whats the EVAP system even do lol ????

 

Fck if i know lol. I wuv my trunk monkey

 

Evap Purge Solenoid doing its Cycle. its perfectly normal.

 

im not mr smarty pants

the evap burns off gas vapor from the tank disabling the evap has no performance benefit my evap solenoid went bad I pluged and turned off all evap codes the car will run fine without an evap I would keep the line in place for future usage

 

idk about that. lol you seem to be the one that has answers for the questions no one knows anything about. im sure you dont know everything but you seem to be very inteligent when it comes to eco's. I'll be meeting Tyler down at CED for the meet on july 25-26. Hope to see you there.. i assume your still going?

 

see!!! lmao

 

Leave a banana in the trunk. Problem solved.

 

Nope!! I tried that one!!

 

I just remember the first night i had my car. Was sitting in my garage inside it alone going through sum **** when i hear the three knocks.

Was like "who the fck is here?!" freaked out. Lol

 

Haha. Mine always does it about 30 seconds after I turn the car off. Confused the hell out of me first time.

 

hahaha, I can't believe im not the only one!. I thought I was losing it. I keep looking for the mystery item that makes the noise lol.

 

haha it messed with me too in the beginning!