Hey guys...

So the past few days I have been hearing a slight "whine" coming from the exhaust when the truck is running. (Its usually my woman, but oddly enough... this time it is different ) It is like a rhythmic whine that speeds up and increases its noise frequency as the engine Revs. Is this symptoms of a bad cat?

I have a magnaflow SI/DO muffler that has been on about a year with no problems.

When I got under the truck, it sounds to me (I could be wrong) like it is coming from the "canister" right below the driver's seat, I have a 2005. Is this a cat or a resonator? Could this be the correct place the noise is coming from?

For what its worth, I used to have a 95 Silverado with a bad cat but it was more of a clanking or churning sound... But what I am hearing now is more of a high pitched whine.

Any help or advice would be appreciated.

 

i've never heard a cat having any sort of high pitched whine or anything like that...usually just bad fuel mileage, and rattling.....does it clunk or anything if you hit it with your hand?

there is a cat under the driver seat....i'd hit it with your hand see if it makes any noise and then go from there...haven't noticed a drop in fuel mileage?

 

I've never heard a cat whine, well the kind in an exhaust system anyway. Usually they break apart and rattle and will almost always cause a restriction that would impede performance and gas mileage.

A high pitched whine that increases with rpms is usually indicative of a fuel pump going. Did you pop the hood and give a listen???

 

Have you checked all of your exhaust fittings? I had an almost whistling noise coming from mine and it just turned out to be an exhaust leak. I had never heard one whistle like that, always thought it was just a ticking or knocking sound.

 

Sorry fellas, I was out of town the past few days. I will check the symptoms more and update on what I find.

Thanks for your help

 

When the cat went out on my uncle's Toyota, after dropping it, he held it up, and a whole bunch of little ***** from bearings rolled out of it. So yea, a rattle noise is what you would hear, not a whining noise.

My uncle's Chevy had a whine when it was an exhaust leak on that. So look for that also.