Hey guys, I need some input FAST, as I am due to drive from Cali to Illinois in a few weeks. Now, my car has the usual LS1 piston slap, but this noise is fairly new. Now, under light acceleration (not heavy or granny, just light) up to about 35 mph it has a slight diesel sound going on. Does not do it at idle, or revving it sitting still. I need some possible causes and solutions, and if she is ok to make the trip... this trip cannot be avoided, as it is part of a permanent change of station (I'm Army). Any help would be appreciated, thanks in advance.

 

Oil pressure?

What where you doing when you first heard the noise?

 

Oil pressure is fine. Noticed the noise during normal driving, maybe bad fuel?

 

Spark knock?

 

You're going to have to post a video with good audio or describe the noise with a lot more detail.

 

Noise isn't audible enough from the cab for a video, and it only happens at a particular amount of throttle during acceleration. I cannot recreate it at a standstill. It started happening after I topped her off at a station in Temecula and drove her home to base (bout 30mi north of Barstow) which is about a 2 1/2 hour trip, and it was raining like mad. And again, the noise sounds like a diesel engine... if I even had the radio on, I prob wouldn't hear it.

 

Sounds like spark knock to me. Mine will do it between 1 and 2k RPMs under normal or light acceleration. Of course, I believe mine is because I need some things adjusted with my custom tune. Yours could be the fuel I suppose - especially if you started noticing it after filling up.

 

How many miles on the car? Run some Seafoam thru it.