I hear a vibrating sound sometimes when in slow moving traffic and just barely accelerating. It sounds like a heatshield on a cat vibrating. But when I looked under the car I didn't see a heatshield on the cat. The only place I saw a heatshield was on the exhaust manifold. Is this most likely what is causing the vibration I am hearing? And is it safe to remove it? I know alot of people on here are running an aftermarket header, so do you reinstall the heatshield when you install the header?

Thanks for any info anyone can provide and if you think the vibration may be something else please let me know.

And one last question, How many cats are on the 2.4?

i think that 08 2.4's have more cats then us but i don't even know how many we have lol

or if your car is equipped with cali emissions

i think that 08 2.4's have more cats then us but i don't even know how many we have lol

or if your car is equipped with cali emissions

i doubt it has cali emissions, it was purchased brand new in texas.

07 and 08 2.4's have 2 cats, the heatshield is safe to remove, you cannot even use the aftermarket heatshield with an aftermarket header. honestly i doubt its your heatshield rattling (because of how it is mounted, its really hard to get it to rattle enough to hit the exhaust manifold). Do you have aftermarket exhaust? Check your exhaust clamps (if not welded) and your exhaust hangers.

I actually have stock exhaust. I will have to take a closer look under the car later today to see if I can see anything else that may be rattling. Does anyone else have any other suggestions as to what it may be? Is it just the way the engine sounds?

I removed the large flimsy heatshield that is under the car because it came loose and was rattling. Haven't had any problems with it removed, its been off over a year.

I removed the large flimsy heatshield that is under the car because it came loose and was rattling. Haven't had any problems with it removed, its been off over a year.

Where exactly is this heatshield that you are referring too?

Your better off using a wrap then a heat shield anyway, since a wrap will help keep the exhaust temp from dropping and slowing your exhaust flow.

Mine started to rattle as well. Have checked all welds and hangers and everything is fine. Let me know if you find anything.

My 05 cobalt ss/sc makes a rattle noise. my friend said it could be a heat shield loose. Any ideas?

sure its not a leak?
i just tightened up some pretty funny leaks i had with my new header/dp.

some of them sounded exactly like that.

sure its not a leak?
i just tightened up some pretty funny leaks i had with my new header/dp.

some of them sounded exactly like that.


HOW DO I FIX THE LEAK IF THERE IS ONE?

check all bolts and snug them up.

did you use new gaskets?

Mine started to rattle as well. Have checked all welds and hangers and everything is fine. Let me know if you find anything.

my rattle ended up being a cracked downpipe. Just a heads up cause others have had the same thing.

Use the manifold reseal kit if you go with a different exhaust system IMO, tighten up the bolts every 2 weeks for about 3 times. My rattle was so annoying, its being fixed ATM.

I thought about wrapping my exhaust would that help the rattle?

Mine actually does the same rattle thing around 2700 rpm.........annoying. I'm going to try and find it in the next couple days.