Excessive engine noise accelerating.

[LeakySeals]

The 05 Malibu classic in my signature. Excessive engine noise inside the cabin when accelerating. Or at least more than I'm used to. Nothing physically wrong with the engine. Quiet and smooth idle for a 4 cylinder. But when you get on it to go in the highway you can definitely hear it straining LOL. I'm not convinced it's an exhaust manifold or donut gasket leak. I don't smell anything. Don't hear anything revving it with the hood open. Its a tiny engine in a large engine compartment and a good amount of the exhaust pipe under the hood.

Can I wrap the exhaust pipe under the hood with some type of material like they do with headers for heat? Does that deaden sound? I noticed it gets warm in the cabin perhaps that exhaust pipe is the cause of that as well.

 

[skyactiv]

How long have you had the car and if nothing is wrong, I'd learn to live with it. Probably the nature of the beast.

 

[maxdustington]

You should sound deaden the firewall. Pull the carpet back and get as high as you can up the firewall with your choice of sound insulation.

Nice little weekend project.

 

[supton]

Tire rotation time? or were they rotated recently? I'm wondering if it's tread blocks.

Oh wait, this is new to you? Might just be the nature of the beast. Or worn motor mounts, allowing excess vibration.

 

[JLTD]

On phone so no signatures can be displayed...

New noise that suddenly appeared?

 

[Snagglefoot]

With the car cold, get under the car and run your hand ABOVE the muffler. Muffler leaks are often on the top side of the muffler where you can't notice them.
The sound bounces around and it's source can be deceiving.

 

[zorobabel]

A friend had (as I recall) an 04 Malibu with a hairline crack in the exhaust manifold.

 

[oldhp]

Check all the intake system hoses, clamps etc. Could have loosened/slipped off. The sound you might be hearing is the throttle body sucking air as you accelerate.

 

[SubieRubyRoo]

Originally Posted by zorobabel
A friend had (as I recall) an 04 Malibu with a hairline crack in the exhaust manifold.


^ This. My mom's 05 Malibu had the same thing. The shop located the crack, drilled a hole at each end of the crack to stop propagation, then TIG welded it shut. I think they charged her about an hour of labor for the repair.

 

[LeakySeals]

Originally Posted by SubieRubyRoo
Originally Posted by zorobabel
A friend had (as I recall) an 04 Malibu with a hairline crack in the exhaust manifold.


^ This. My mom's 05 Malibu had the same thing. The shop located the crack, drilled a hole at each end of the crack to stop propagation, then TIG welded it shut. I think they charged her about an hour of labor for the repair.

Was that the 2.2, 2.4 or some other size? I have the 2.2.

 

[SubieRubyRoo]

I think it was the 2.4; it's been a couple years since she had it.

 

[Linctex]

Make sure your cat converter isn't plugged.

 

[Nick1994]

Could be plugged cat or an exhaust leak, it doesn't have to smell.

But I'm betting on bad motor mounts and something is 'off' and rubbing somewhere along the line.

 

[DejaVue]

Originally Posted by LeakySeals
But when you get on it to go in the highway you can definitely hear it straining LOL.

Can I wrap the exhaust pipe under the hood with some type of material like they do with headers for heat? Does that deaden sound?

Posting a video with good audio can help.

I wouldn't bother wrapping anything until figuring out exactly what the problem is. Whether something is cracked, broken, or if that's simply the way it's supposed to sound from the factory.

 

[LeakySeals]

Will post a video when things warm up. It seems to be coming from this area.

 

[dishdude]

Maybe you'll get lucky and that exhaust donut is worn out.

 

[LeakySeals]

The weather is getting better so I can finally take a closer look. Is that some type of flex pipe?