Rattle noise

Tiny
ROBERTBARNES62
  • MEMBER
  • 2003 CHEVROLET SILVERADO
  • 6.0L
  • V8
  • 4WD
  • AUTOMATIC
  • 192,000 MILES
Hello,

I have the truck listed above SS model. I have found sometimes when accelerating up an incline I hear a rattle noise. It does not do it when I’m cruise control.

To further describe the condition of when I hear the noise I will say if I am on the highway going 65 and start to press the gas pedal, I hear the noise but if I continue to push the gas pedal down more to give it more gas the noise goes away. This only seems to happen on inclines.

Any help would be great.

Thank you.
Tuesday, March 8th, 2022 AT 7:55 AM

11 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,179 POSTS
Hi,

Based on your description, it sounds like the internal portion of the catalytic converter may have come loose and causing the sound.

Do this. Take a rubber mallet and tap on the exhaust to see if you can recreate the sound. Have a helper listen to determine if that is where the noise is coming from in that area. Also, here is a link you may find of interest:

https://www.2carpros.com/articles/bad-catalytic-converter-symptoms

Let me know.

Joe
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Tuesday, March 8th, 2022 AT 3:50 PM
Tiny
ROBERTBARNES62
  • MEMBER
  • 83 POSTS
Thank you for the reply but the truck does not have a catalytic converter on it. It was removed when the exhaust was redone about 10 years ago.

Any other ideas on what it could be? It is definitely coming from the engine compartment, or at least that is what it sounds like. Can injectors make a rattle noise? If so, would it make a difference from when I slightly press the gas to when cruise control is being used?

I find it so weird that it only makes that noise when I am slightly pressing the gas on an incline.

Thank you for any ideas you may have.
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Tuesday, March 8th, 2022 AT 5:11 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,179 POSTS
Hi,

The injectors do make a noise, but you would never hear it in the vehicle. I agree with you. This is a strange one. Are there any other sounds you have noticed? Also, when you hear the sound, is there anything that will change the volume or tone of it?

Just for the heck of it, take and tap on the exhaust in a few different places to see if you can reproduce the sound.

I do have another question. I'm wondering if you are hearing valve ping. Although it is normally most obvious when under a heavy load, anything is possible. Is it loud enough for you to record and upload for me to hear?

Let me know.

Joe
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Tuesday, March 8th, 2022 AT 6:14 PM
Tiny
ROBERTBARNES62
  • MEMBER
  • 83 POSTS
No other sounds that I have noticed. Nothing changes how it sounds either. I have tapped on the exhaust and cannot reproduce the noise.

What causes and to fix valve pinging?

As far as recording I will try to record it. My truck is very loud due to the cam and exhaust so I'm not sure how well it will pick it up, but it is worth a shot. And it does not do it every time I drive but I will try to record it for sure.
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Wednesday, March 9th, 2022 AT 3:52 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,179 POSTS
Hi,

Valve ping is usually the result of poor fuel quality, ignition timing, or a faulty knock sensor. Have you checked for diagnostic trouble codes?

Let me know.

Joe
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Wednesday, March 9th, 2022 AT 1:16 PM
Tiny
ROBERTBARNES62
  • MEMBER
  • 83 POSTS
I wonder if it’s just bad gas then. I have checked the codes with a snap on diagnostic computer my buddy has, and it doesn’t have any codes.

I was reading that it could be due to carbon build up in the throttle body. Does that sound right? If so, should I clean it?
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Wednesday, March 9th, 2022 AT 1:53 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,179 POSTS
Hi,

It wouldn't be a bad idea to clean the throttle body, but I question if that is the cause.

With prices at this time, I'm reluctant to suggest this, but if you can run a tank of premium fuel through it, that should eliminate the possibility of it being a low octane fuel issue.

Let me know.

Joe
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Wednesday, March 9th, 2022 AT 1:59 PM
Tiny
ROBERTBARNES62
  • MEMBER
  • 83 POSTS
Okay, I will give it a clean. On these trucks it is self-learning after I clean it right?

And all I use in it is premium gas but the last time my brother filled it up he said he didn’t know and put regular in there so that might be the problem.

Thank you
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Wednesday, March 9th, 2022 AT 2:26 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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Hi,

Yes, it will relearn by itself.

Also, here is a link that explains in general how to service a throttle body.

https://www.2carpros.com/articles/throttle-actuator-service

I attached the directions from my manual below. They are vague. LOL

Let me know if this helps or if you have other questions.

Take care,

Joe

See pic.
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Wednesday, March 9th, 2022 AT 4:13 PM
Tiny
ROBERTBARNES62
  • MEMBER
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Thank you.
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Thursday, March 10th, 2022 AT 5:14 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,179 POSTS
You are very welcome. If you have a chance, let me know how things turn out for you.

Take care,

Joe
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Thursday, March 10th, 2022 AT 5:09 PM

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