Mild Knock

**robert 98** · 06-02-2009, 01:51 PM

I've noticed latley that my car seems to have a mild knock under light acceleration anyone else ran into this?

**Too Fast** · 06-02-2009, 01:54 PM

Sounds like the normal noise our LS1 engines make, and maybe now you are only hearing it. Some are louder than others, and most make it more before warmed all the way up. It is actually piston slap. Yours goes away or gets a lot quieter when warmed up?

**robert 98** · 06-03-2009, 02:03 AM

Yeah I do have some noise at start up that goes away, but this is more like valve chatter when I accelerate lightly like if I'm going up a hill and give it a little more throttle I can hear it,

**JoshieDoom** · 06-03-2009, 02:06 AM

Bad gasoline???

**robert 98** · 06-03-2009, 02:15 AM

Possibly, I am running 91 octane but it could be bad I guess, I was running Sunoco and never heard anythig I think I'll switch back and see what happens

**JoshieDoom** · 06-03-2009, 02:19 AM

Very possible. If the gasoline doesnt cure it I would log and see what is going on before any damage is done.

**robert 98** · 06-03-2009, 02:26 AM

Thanks Doom, how would I go about logging it? Dumb question I know

**JoshieDoom** · 06-03-2009, 02:27 AM

Originally Posted by robert 98

Thanks Doom, how would I go about logging it? Dumb question I know

Find someone with a scanner that can log knock and sensor outputs.

**robert 98** · 06-03-2009, 02:28 AM

Ok man Thanks again

**robert 98** · 06-03-2009, 04:56 PM

It must have been bad gas fortunatley I only got about half a tank last time I got gas, got some today at a different station and the noise went away, I guess from here on out I'll stick with Sunoco!

**Durango** · 06-03-2009, 05:26 PM

Amazing isn't it. I'm getting a little spark knock at higher rpm's and I just changed my wires and plugs but I bet you it's the gas as I went to a different gas station that I usualy go to
Hum I'll try different gas next time

**Firebirdjones** · 06-03-2009, 05:54 PM

Originally Posted by robert 98

It must have been bad gas fortunatley I only got about half a tank last time I got gas, got some today at a different station and the noise went away, I guess from here on out I'll stick with Sunoco!

Ya some of that stuff out there now is just pure crap. I won't even run it in my lawn mower. Really have to watch where you get gas anymore, and even that isn't guaranteed. I've used Sunoco exclusively for years without issue. Best to stick with the larger chains like Shell, BP, Sunoco, and cross your fingers. I don't think it's going to get any better unfortunately.

**JoshieDoom** · 06-04-2009, 12:30 AM

People always want to save a buck here and there and it ends up costing them more by cheaping out.

**Too Fast** · 06-04-2009, 02:14 AM

Originally Posted by JoshieDoom

People always want to save a buck here and there and it ends up costing them more by cheaping out.

^^^This man speaks wisdom beyond his years....

Robert 98, glad to see it was a simple solution. I was beginning to think you had valvetrain problems.