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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 29522
Experience:  GM Grand Master Technician 2007. 14 years experience.
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I have a knocking on left side and no throttle, Injecters

Customer Question

I have a knocking on left side and no throttle
JA: Where exactly do you think the noise is coming from? And how long has this been going on?
Customer: Injecters and for awhile
JA: What is the model/year of your Chevy?
Customer: 2004 6.6 turbo
JA: Are you fixing your Turbo yourself? What have you tried so far?
Customer: I have tried nothing
JA: Anything else you want the mechanic to know before I connect you?
Customer: It as no throttle up
Submitted: 10 months ago.
Category: Chevy
Expert:  GM Tech (Cam) replied 10 months ago.

Hi there, I am Cam.
Does the knocking go down or away when driving?

Customer: replied 10 months ago.
No
Expert:  GM Tech (Cam) replied 10 months ago.

Ok the surface it sounds like an injector. We can tell by the balancing rates on the injectors at idle when hot. Spec is +/-4 on each and any outside of that is excessive and requires replacement.
second likely issue is a push rod issue.

For now, check the balancing rates and see.

Customer: replied 10 months ago.
How I check balancing rate
Expert:  GM Tech (Cam) replied 10 months ago.

That is only done with a scanner. The balancing rate is the computer trying to adjust the flow rate on each injector to keep things running smooth. Outside of that spec shows that the computer is noticing differences and is trying to adjust it. IF you see an injector at -15, that suggests its leaking or +15 is the injector plugged or not flowing properly.
Again this is only done with a scan tool.

Customer: replied 10 months ago.
Is it a special scan tool
Expert:  GM Tech (Cam) replied 10 months ago.

It would be a full scanner, like the GM tech 2, snap on solos. Not a code reader.

Customer: replied 10 months ago.
Can I pull the wire off the injected to figure out which one it is as its running
Expert:  GM Tech (Cam) replied 10 months ago.

No, because the injectors are in groups, killing one injector will kill the group and they re also 93volts so its dangerous.

Customer: replied 10 months ago.
I don't have scanner any other way to check them
Expert:  GM Tech (Cam) replied 10 months ago.

Thats not good. I wish I could tell you another way to do this but there is no other way. the nature of the system prevents simple testing.

Customer: replied 10 months ago.
if it blows white smoke does that mean a injecter
Expert:  GM Tech (Cam) replied 10 months ago.

Smoking also is an indication of injector, yes. Given these issues I am really thinking you need injectors.
Have they ever been replaced?

Customer: replied 10 months ago.
No how much do you think it would cost to replace the injecters
Expert:  GM Tech (Cam) replied 10 months ago.
It's a 10 hour job and the injectors are about 200 each. I recommend you buy good quality injectors. If you buy cheap ones you usually have issues.