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Strange sound when RPM > 2000

Posted: Thu Nov 02, 2023 2:11 pm
by ditomathew
My 2009 vibe 2.4L is making this weird noise while moving and revving above 2000rpm. If I release the gas, the sound goes away. It doesn't make this noise when stationary.

Does any one have any clue what's causing it? My mechanic said he couldn't find anything wrong. He had replaced the Exhaust Pipe Flange Gasket for fixing a leak after which I started noticing this sound.

It has a hesitation in uphill and heavy acceleration. But that has been there before this sound.

I did run through a bottle of liquimoly catalytic cleaner to see if that helps, but apparently it didn't.

https://youtube.com/shorts/GKtJdrjsj0c? ... wf54ZqO8RW

Re: Hissing sound when RPM > 2000

Posted: Thu Nov 02, 2023 2:54 pm
by SeattleJeremy
ditomathew wrote: Thu Nov 02, 2023 2:11 pm Does any one have any clue what's causing it? My mechanic said he couldn't find anything wrong. He had replaced the Exhaust Pipe Flange Gasket for fixing a leak after which I started noticing this sound.
https://youtube.com/shorts/GKtJdrjsj0c? ... wf54ZqO8RW
You have an exhaust leak. The fact that your mechanic made a change to the exhaust, then the noise started, confirms it.

It's really common for people to install the wrong exhaust flange gasket. It'd bet a shiny nickel they installed the 1.8L doughnut (EG Felpro Part No. 61124) on your 2.4L car (needs the larger/more expensive Felpro Part No. 61106). Take it back to your mechanic.

Re: Hissing sound when RPM > 2000

Posted: Thu Nov 02, 2023 3:18 pm
by ditomathew
The part he mentioned is NIC31639. Is that the right one?
Earlier I had gasoline smell reaching the cabin. But after the work he has done, it has stopped.

Re: Strange sound when RPM > 2000

Posted: Mon Nov 06, 2023 12:33 pm
by SeattleJeremy
The only relevant information on Google for "NIC31639" are this thread, and the thread you posted to Reddit.
https://www.reddit.com/r/AskMechanics/c ... bove_2000/

Searching just the numbers shows us, which might be the right one.
https://www.amazon.com/Walker-31639-Exh ... B006EHLHWS

Moving/installing the gasket above might have caused an issue with one further down the exhaust pipe. I still recommend having the shop that did the work look for leaks. It should be pretty apparent with the car on the lift and running where the sound is coming from.

Re: Strange sound when RPM > 2000

Posted: Mon Nov 06, 2023 6:18 pm
by joatmon
https://www.oreillyauto.com/detail/c/ni ... nicb/31639 has a check if this vehicle fits your car thing, and when I put in a 2009 Vibe with 2.4L engine, it says "Does NOT Fit 2009 Vibe "

Re: Strange sound when RPM > 2000

Posted: Wed Nov 15, 2023 10:04 pm
by ditomathew
I did buy the right donut gasket myself and changed it. But sound is still there. So something else is causing it. Thinking of checking for vacuum leaks by spraying carb cleaner.

My Engine Air Filter Box clamps are broken and currently held by just one. Will it cause the sound?

Re: Strange sound when RPM > 2000

Posted: Wed Nov 15, 2023 10:10 pm
by ditomathew
I also drained and refilled the transmission fluid with Valvoline ATF, which has effectively reduced the hesitation I was experiencing during acceleration.

Re: Hissing sound when RPM > 2000

Posted: Sat Nov 18, 2023 8:16 am
by ditomathew
SeattleJeremy wrote: Thu Nov 02, 2023 2:54 pm
ditomathew wrote: Thu Nov 02, 2023 2:11 pm Does any one have any clue what's causing it? My mechanic said he couldn't find anything wrong. He had replaced the Exhaust Pipe Flange Gasket for fixing a leak after which I started noticing this sound.
https://youtube.com/shorts/GKtJdrjsj0c? ... wf54ZqO8RW
You have an exhaust leak. The fact that your mechanic made a change to the exhaust, then the noise started, confirms it.

It's really common for people to install the wrong exhaust flange gasket. It'd bet a shiny nickel they installed the 1.8L doughnut (EG Felpro Part No. 61124) on your 2.4L car (needs the larger/more expensive Felpro Part No. 61106). Take it back to your mechanic.
Do you know what's the bolt needed to secure the pipe to converter with this gasket ?

What I currently have is a spring bolt like below link, but it says does not fit 2.4L Vibe. The auto part store gives me normal nut bolt as the right part.

https://shop.advanceautoparts.com/p/dor ... 22148977-P

Re: Strange sound when RPM > 2000

Posted: Mon Nov 20, 2023 9:06 am
by SeattleJeremy
The spring bolts are best, because that's how they came from the facotry.

Re: Strange sound when RPM > 2000

Posted: Mon Nov 20, 2023 1:32 pm
by joatmon
The spring bolts allow some movement between the pieces, if they are hard locked together, it puts a lot of strain on the parts.

My son had a shop replace the power steering pump in his Matrix, and they left a motor mount disconnected. Put the car under a load, then engine would shift enough where one of those spring loaded joints would open up. Made a hell of a racket. found it by having one person stand hard on the brake pedal so the car wouldn't move and hit the gas in gear, another standing to the side (out of the way ;) ) watching the engine. If really flopped about.

Also, if the mechanic replaced the one gasket, its possible that a different joint got flexed and weakened.

a really sketchy way to find out if its that joint between the cat and the muffler would be to tightly wrap something like an old towel around the joint, tie it on tight. Something to act as an external gasket, muffle the leak. If that's where its coming from, it will sound different. Obviously, you would want to be sure to do it only when the engine and exhaust both cold, and only run that way for a really short period of time. Also Obviously, if you do something like that and set your car on fire you can't blame me if you take insane advice from some random nutjob wacko on the internet ;)