Knocking noise at idle

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Knocking noise at idle

Postby tksGTB » Fri Jul 21, 2017 8:33 pm

Hey guys I need your help. On the weekend my car just started making a knocking sound and it now somewhat sounds like a diesel. The sound can only be heard from inside the car when the doors are closed and above 1500rpm it stops. I can't hear or locate the sound from the outside. I took it to a mechanic who was said it was normal but I feel like there's more to it. Do you have any ideas or suggestions on what it could? Or maybe I'm just being paranoid.
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Re: Knocking noise at idle

Postby tom_kauf » Tue Jul 25, 2017 4:31 pm

Hi tksGTB, could you post a video? Eg just record on your phone and upload to YouTube. Otherwise it could be many things, so it's a bit hard to help without hearing it.
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Re: Knocking noise at idle

Postby tksGTB » Fri Aug 11, 2017 1:21 pm

hey tom_kauf i will record a video today and post it on youtube and then add it on here tonight. I still have no ideas what's wrong with it.
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Re: Knocking noise at idle

Postby tksGTB » Fri Aug 11, 2017 1:26 pm

https://www.youtube.com/watch?v=RoAhJ-RVBZc

You can barely hear the sound. It also fades as the car gets warmer
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Re: Knocking noise at idle

Postby tom_kauf » Fri Aug 11, 2017 7:01 pm

Thanks for the upload. It doesn't sound too different to my car to be honest.
Is your exhaust stock? All I hear is an exhaust rumble that may be a leak in the exhaust (or join between sections). Or just aftermarket mufflers - some types have packing that degrades over time, making them louder.

Since you mention it can only be heard inside the car, it might be in the front section of the exhaust - maybe at the dump pipe. My exhaust is stock except for the dump pipe, so it's a tiny bit louder than factory (but barely noticeable). So maybe that's why I think your car sounds like mine.

And it's not just on cold starts, or is it? Because the Secondary Air Pump, which is used for emissions makes the car sound like a diesel on cold starts. But only for the first 20sec or so.
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Re: Knocking noise at idle

Postby tksGTB » Fri Aug 11, 2017 8:11 pm

The exhaust is stock. The sound can be heard clearly on front passenger side of the transmission tunnel. As the cars gets warmer it's not as loud but I can still hear it.

Do you suggest I should get the exhaust checked?
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Re: Knocking noise at idle

Postby vinshonz » Sat Aug 12, 2017 2:45 pm

can you get a better recording of this sound?
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Re: Knocking noise at idle

Postby tom_kauf » Sat Aug 12, 2017 4:41 pm

tksGTB wrote:The exhaust is stock. The sound can be heard clearly on front passenger side of the transmission tunnel. As the cars gets warmer it's not as loud but I can still hear it.

Do you suggest I should get the exhaust checked?


Hmm, it's interesting that the sound is louder on the passenger side. Because the GT exhaust goes down the driver's side. But yeah, get it checked. Unless someone can suggest something else, I can only hear an exhaust rumble.
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