Help: Bad injector?

[jwinnie]

When I start the truck cold, one cylinder is louder than the others. Warmed up it is barely noticeable. I have to assume the injectors are original.



Before I buy new sticks, is there a way to verify it's not a rod bearing



John

 

[champspa]

I'd switch that injector to another hole and see.

 

[jwinnie]

Thanks, I have not identified the cylinder yet. I'm guessing the best way is to loosen the injector lines one at a time with the engine running?



Sorry for the elementary questions, I'm still a first gen newbie.

 

[Greenleaf]

I am told the heat gun method works. I tried it a number of times and it proves nothing. You may very well loosen one at a time. The best method is old school. Pull them all and check them on the bench w/a pop tester. Or have a shop perform this.

 

[jwinnie]

Well I narrowed it down to the #6 cylinder. When I loosened the #6 line, the noise went away. I swapped the #1 and #6 injectors with no change.
It doesn't sound like a rod knock, it's like that cylinder is just louder than the others but all is quiet and smooth at higher rpm's.

Any ideas?

 

[Midnite]

I think I'd take them to a shop that can reset them to the correct pop-off pressure. It sure sounds like the one you identified is popping at a lower pressure than the others.

Mike