2002 Sierra Plugged Injectors

[sagent]

At about 66000 miles I had to bring my 02 Sierra into the dealer due to truck feeling as if it were running on 6-7 cylinders ( 5.3 L). Sure enough dealer scanned computer and showed 2 injectors likely clogged. Extended warranty company said injector flush would not be covered due to fact fuel was contaminated ????

I spoke technicican at extended warranty company ( Tech Serve ), who claimed to be an ASE certified tech of 20+ years, and he told me once fuel filters reach a certain point/ age/ milage , the filter media will start passing all contaminants straight through to injectors ( Bullxxxx) . Reluctantly, I ended up paying the$ 150 to have flush performed and it did fix the problem. Now with about 77000 miles i have the same problem back again. I have not scanned the truck yet but it is doing the same exact thing so I am betting plugged injectors. Are there any Techs that can shed some light on why this problem reoccurs and why I must pay for it? I have been running 2 bottles of Seafoam in the tank every month or so since initiakl flush and have changed fuel filter at abt 50,000 and again at abt 69,000

 

Thanks much

[ChevyTech007]

I bet the cylinders going dead are 5, 7, and possibly 8. If it is you need to have them pull the injectors out and I bet the inlet of the injectors will be packed with rust particles. The particles come from the inside of the fuel lines deteriorating from additives in the fuel. It happens after the fuel filter, that is why the filter does not catch it. I have seen it more than once. You will have to replace the lines, physically clean the injectors and then run injector cleaner through one more time.

[sagent]

I bet the cylinders going dead are 5, 7, and possibly 8. If it is you need to have them pull the injectors out and I bet the inlet of the injectors will be packed with rust particles. The particles come from the inside of the fuel lines deteriorating from additives in the fuel. It happens after the fuel filter, that is why the filter does not catch it. I have seen it more than once. You will have to replace the lines, physically clean the injectors and then run injector cleaner through one more time.

 

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Thanks very much. Matter of fact I pulled the codes and it set off a P0308 . # 8 cylinder. I checked resistance on the injector and came up with 14.2 ohms. Too high as per chiltons. I also checked resistance of # 2 injector and came up with 16.6 ohms, which is supposed to be way to high. I swapped ignition coils on #6 and #8 cylinders, ran vehicle until SES light flashed and then stayed on steady. I then ran the codes again and came up P0308 again, # 8 cylinder.

 

Does this sound like the injector clogged again or should I pull the plug from # 8 and examine?

[pm26]

The best way to avoid these issues is to use brand name fuel and stay away from no brand cheap gas stations. You are asking for it, IMHO. You never know what they dump into their gas to make it cheaper.

[jhm]

I think you should stop putting seafoam in that truck immediately. That stuff is a powerful solvent and is probably deteriorating the inside of your fuel line. You cant get a mechanic in a bottle. People been buying this snake oil for decades, does nothing but cause problems. I remember in high school auto shop in the 70's taking a teachers carb apart because it was running bad. He insisted he used STP fuel treatment regularly. Well the inside of the carb was encased in crystal like particles. I remember the instructor saying that is what STP does to a carb. Now Seafoam is the flavor of the month.

[sagent]

Up until the first time the injectors were plugged I did not use any type of additive in the gasoline at all. As per every GM owners manual I have read, it specifically states no additives of any type are required for GM vehicles. Since the first injector flush I have switched / alternate gas stations also.

 

Yesterday I dumped in 3 bottles of b-12 chemtool in the tank and topped it off. Drove vhicle for abt 20 miles yesterday. This morn started vehicle and it runs fine. I am assuming additive went to work last night on injector and or heating / cooling of engine . Am I expecting too much from my extended warranty company to cover this type of repair? I feel I should not have to pay $ 150.00 every 6 months to flush the injectors. Has anyone else had these issues?