Engine Grinding noise

2008 CHEVROLET SUBURBAN
239,000 MILES • 5.3L • V8 • 2WD • AUTOMATIC
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SAMIAMINMN
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When I turn my key to on, not actually trying to start the vehicle, I hear a grinding noise, it seems to be coming from somewhere near the intake. When driving the vehicle this noise goes in and out as well. My oil pressure gauge is not registering any pressure either. Oil level is full and I just had it changed.
Dec 8, 2019 at 9:05 AM
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AL514
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Hello,

Can you record the sound so we can hear it please?video is fine too. These Chevrolet's have all kinds of strange grinding noises.
Dec 8, 2019 at 9:25 AM
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SAMIAMINMN
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Video added.
Video (Click to enlarge)
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Dec 8, 2019 at 10:44 AM
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AL514
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Okay, these vehicles have an air injection system to pump more air into the engine. That's what it sounds like to me. It's definitely a strange noise. The pumps go bad causing these noises. And actually it's supposedly pretty easy to change. But that's my diagnosis.
Dec 8, 2019 at 11:01 AM
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STRAILER
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Can you take another video for under the hood if that is where the noise is coming from please? Can you tell where the noise is coming from?
Dec 8, 2019 at 11:13 AM
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AL514
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Can you take that plastic cover off the top of the intake? It sounds very close to the throttle body.
Dec 8, 2019 at 11:26 AM
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SAMIAMINMN
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Video added, starting it as well.
Video (Click to enlarge)
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Dec 8, 2019 at 11:31 AM
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AL514
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So what you can do, is start unplugging things and try it with just the key on, not running and see if you can isolate the noise.
Dec 8, 2019 at 11:36 AM
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SAMIAMINMN
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Tried disconnecting multiple plugs and couldn't isolate the noise.
Dec 8, 2019 at 12:12 PM
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AL514
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Did you unplug the throttle position sensor? And the idle control valve? I've read up on this and it always seems to be the throttle body. And is this drive by wire system? Meaning no cable for the throttle plates, just an actuator that moves the throttle.
Dec 8, 2019 at 12:47 PM
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AL514
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Also try unplugging the abs unit, it may be running a self test at key on.
Dec 8, 2019 at 12:49 PM
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SAMIAMINMN
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Did the throttle body unit, that is what was making the sound.
Dec 8, 2019 at 1:01 PM
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SAMIAMINMN
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Replaced the throttle body unit, no more grinding.
Dec 8, 2019 at 2:44 PM
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AL514
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Good news.
Dec 8, 2019 at 4:02 PM