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John, Master A.S.E Automotive technician
Category: Chevy
Satisfied Customers: 9176
Experience:  A.S.E MasterTechnician A1-A8 w/L1,38 years experience General Motors Master Technician
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2002 chevy silverado 2500 hd: 6.6 duramax..white smoke at

Customer Question

I have a 2002 chevy silverado 2500 hd 6.6 duramax. It recently started putting out a lot of white smoke at idle. It smells very rich. I've read in forums that its probably one or more injectors that have corroded and are leaking fuel into the cylinders. Is there some kind of test or something that i can do to be sure of this before i make that expense?
Submitted: 7 years ago.
Category: Chevy
Expert:  John replied 7 years ago.


How many miles are on your vehicle ?

Customer: replied 7 years ago.
Customer: replied 7 years ago.
If there are any bad injectors, what kind of reading would I get?
Expert:  John replied 7 years ago.

If there are bad injectors,they would be outside the pass balance rares,which are


-6 mm³ and +6 mm³

-4 mm³ and +4 mm³


The balance rates are the fuel adjustments for each individual cylinder based on the variations in engine crankshaft speed. A positive value indicates that fuel is being added to each cylinder event, such as with poor engine compression or a fuel injector that is not flowing enough fuel. A negative value indicates fuel being removed from each cylinder event, such as a fuel injector that is flowing too much fuel. The balance rates will change depending on if the transmission is in Neutral or Drive.

Customer: replied 7 years ago.
I went to my friends shop and scanned my truck. He doesn't have a tech 2 and it doesn't show the individual cylinder balancing rates. But it shows an injector fuel rate. In drive at Idle it stays between +7 mm3 and +8.5 mm3. In nuetral at idle it stays between +3.5 mm3 and +4.5 mm3. I dont know if that tells you anything. Is there anything else besides the injectors that might cause that problem?
Expert:  John replied 7 years ago.
This is the most likely thing if there are no failure codes. Every engine has it's faults & this has been the weak point of this one,I have replace a bunch. Make sure the engine temperature sensor is reading correctly.By this I mean if it is 50 degrees out ,a cold engine temperature should read with in a few degrees of this.
Customer: replied 7 years ago.

It does show 2 faults. P0540 air intake heater circuit. and the other one was the glow plug circuit, i dont remember the # XXXXX sure but i think it was P0380.

Expert:  John replied 7 years ago.
Both of these codes are a part of the starting system,they would not be the cause of your original problem.
John and 2 other Chevy Specialists are ready to help you
Customer: replied 7 years ago.
Thanks for your help.
Expert:  John replied 7 years ago.
You are very welcome.