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LBZ engine knocking sound around 1200 to 1500 rpm, light…

Customer Question
LBZ engine knocking sound...

LBZ engine knocking sound around 1200 to 1500 rpm, light load

Mechanic's Assistant: Where exactly do you think the noise is coming from? And how long has this been going on?

About 2 months, from engine compartment. noise seems to go away when given heavy or full throttle

Mechanic's Assistant: What is the model/year of your Chevy?

2007 silverado HD, LBZ diesel

Mechanic's Assistant: Are you fixing your Silverado yourself? What have you tried so far?

Fuel aditive, made sure oil level is good

Submitted: 4 months ago.Category: Chevy
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Answered in 24 minutes by:
3/8/2018
Chevy Mechanic: GM Tech (Cam), Chevy Technician replied 4 months ago
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 30,400
Experience: GM Grand Master Technician 2007. 14 years experience.
Verified

Hello there, I am Cam.

I am Licensed technician at a GM dealership with more than 16 years experience. 
Like you, I am a user of this website and as such, any billing questions should be sent to customer service.

I ask that you please provide details and communicate with me so we can make your experience here worth 5 stars! I am around most days but not every minute of every day. If you reply while I am offline, I will respond when I am next online. 

I am reviewing your request and will post in a moment.

Most often an odd knocking noise in these is related to a failing injector.

The test I would perform is to disable injectors one at a time with a scan tool to see which makes it stop then replace just that injector. unplugging it to test would not do the same as it disables more than just one.

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