i really dont know where to begin tracking down this issue. i get a hissing/buzzing sound from somewhere in the engine bay. it only happens under wide open throttle. or near it. at above 3500 to 4000 rpm while the engine is in gear and under load. i cant make it do this out of gear. its a 2008 hhr ls. i am leaning towards an exaust leak. but i cant be sure any more due to my failing hearing. worked on running aircraft engines for the navy for 8 years. im sorry i cant be more helpful

 

to the forum!

At first blush, it sounds like a classic flex pipe leak in the exhaust, the following thread shows the most economical way to fix a leaking flex pipe, and what exactly we're talking about.

Just click the link below...

https://www.chevyhhr.net/forums/how-tutorial-library-21/how-repair-flex-pipe-31536/

With the engine running, you can stick a strip of paper down there to see if it's blown back by leaking exhaust. Never use your hand unless you're wearing heat resistant gloves, it's hotter than blazes back by that manifold.

P.S. Thank you for your service Sir.

 

Welcome to the site.

I agree my first guess would be a leaking flex joint.

 

Welcome to the forum......

 

Welcome!

Happy that my "how to" is still helping others!

 

i would likw to thank everyone for the warm welcome and the advice. heres an update of the situation.

it looks like i had a failed motor mount and put too much stress on the flex pipe. theres a crack in it all right. ive replaced the mount. and i will replace that flex pipe when the weather warms up again. please forgive my failure of typing skills. im posting this from my phone.

once again. thank you all

 

I'm glad you got it figured out. Just be careful driving you a car with an exhaust leak. Carbon Monoxide can enter the passenger compartment.

Carbon Monoxide is color less and has no smell.

I found out years ago the hard way. I may father and I made a 4 hour trip in a car with pin holes threw out the exhaust. When we arrived we past out in the drive way and woke up in the hospital with no memory of what happen.

It scared me to the point that I'm always carful about ensuring that my vehicles exhaust systems are in good shape.

 

X2 on the Carbon Monoxide.

It'll get you in a hurry, and when you notice the symptoms like nausea, headache, dizziness, shortness of breath, sleepiness, and weakness, it may be too late for you to get help on your own.

 

Thanks mike. That's what I get for sneaking onto the computer when I'm suppose to be working on my honey do list.

 

No worries mate, we won't tell on ya.