Chevy Silverado 5.3L 4wd 2002 Piston Knock
Posted in Crank, Oil and Piston | Asked on Aug 27, 2010
I asked a different question about a certain knocking sound which I thought was coming from my valve train, some people tell me that it may be piston slap or pistons are actually knocking but if my pistons were slapping against the cylinder wall or if my pistons were knocking then wouldnt this also set a check engine light if the knock sensors detected something or would the knock sensor just retard the timing without throwing a check engine light? The question I asked a couple days ago should be under my profile under the questions I asked.
There are 3 Answers
Make sure that you are using good quality fuel. Poor fuel quality will give your truck a knock (precombusition) sound.. I also recommend using Lucus Oil’s Fuel Additive.. I have gone through this with my El Camino.
An EGR valve can cause this problem,without the check engine light coming on.
As long as the computer is getting a signal from the knock sensor it is not going to throw a code retard timing yes. A piston knock will always be a double knock and will go away when the plug wire is removed from the offending cylinder. I don’t recommend pulling the wire while it is running or running the car without the wire going to a good ground that was ok in the good ol days but now you are likely to damage another part, and they are all expensive parts these days. good luck