Engine Noise Gone

[95 chev]

0I have a 2008 silverado 2500 HD with the 6.0engine. The truck has (had) what I would call a valve tap. It would do it all the time, but I would really notice it when I would be going about 40 or 50 mph and take my foot off the gas to stop at a red light. I took it to two different dealers, and both said that it was normal fuel injecter noise. I was very annoided with the noise, I could not believe that GM would feel that the noise was acceptable. Anyway, I was talking about it at work the other day and one of the guys suggested putting higher octane gas in it. Even though I KNEW that higher octane gas was not going to help, I put a tank of 93 octane in it. I drove to work this morning (30 miles) and when I got off the highway I turned down the radio and listened for the noise,and it was not there. I even tried to make the noise and it was not there anymore. Anyone ever hear of this before? Are these trucks suppose to have the higher octane fuel? My selling dealer told me to run 87 octane.

[jro909]

eh i think some of the 6.0s take premo fuel, i remeber reading a thread on here about a guy asking if he could run 87 octane when his 6.0 called for premium...also every 6.0 i have ever seen makes that noise, i have no idea what it is, but i notice then it does it under load

[hockeypro1411]

eh i think some of the 6.0s take premo fuel, i remeber reading a thread on here about a guy asking if he could run 87 octane when his 6.0 called for premium...also every 6.0 i have ever seen makes that noise, i have no idea what it is, but i notice then it does it under load

 

The 2500HD LQ4 6.0's all run on 87. The 6.2's all run on 93, I believe.

[angelic0-]

LQ9's should be run on 93 or higher octane... that's what i was told...

[dewfpo]

Off the wall here but........ Name Brand PUL has more cleaning agents then RUL. If the noise you are hearing is from carbon buildup; it is possible the PUL is cleaning some of that out and the engine is a little quieter. You could try running a bottle of Techron thru your fuel system and then going back to RUL and seeing if it is still quieter than before. Just a guess.

 

DEWFPO