Pinging noise near 4k RPM

[PewterLS06]

Hello all, I'm a new owner of a lightly used 2006 LS V8 with 6,000 miles. I hope someone can help me out...

I've noticed a pinging noise coming from the engine under hard acceleration between about 4k and 5k RPM. It doesn't sound like engine knock (I've tried using different brands of high octane fuel, retarded the spark timing, changed the oil, but still get the same sound). Dealer says this is normal valve noise for LS engines, but I'm not so sure.

Does anyone have experience with this sound, or know whether it is actually normal, related to the variable valve timing, etc.?

Any input/experience would be appreciated. Thanks!

 

[mnmridg]

Same deal here.
'06 with 13 k. About 4k under moderate to heavy throttle opening it starts to spark knock in 3rd gear. 1st and 2nd are fine.
I tried two different brands of fuel and it is still doing it, so I will do a complete filter change to see if that helps...
Any body else...?
Any Ideas...?
Stealership is next and I hope I don't get "...Normal valve noises..."

 

[ToddG]

Mine does the same thing (06 LS w/27K miles). The LS V8 engine is very high compression, so I'm not too surprised about the knock.

I chalk it up to crappy (winter blend) gas. Around here, they add 10% ethanol to the winter blends which (1) causes engine knock, and (2) causes mileage to go down about 10%. Now on summer blended gas, I got pinging, but not so extreme as in winter. On the summer blend, I could add some octane booster, and it would go away, but no such luck doing the same thing on winter blend.

 

[firmbiz94]

same thing happened to me and i have an 05 v6..i noticed it after i filled up with 87 instead of the usual 93... a clean tank of 93 and some octane booster solved it for me tho..

 

[Machspeed]

06 V8, 10k miles....pings on most available 91 octane gas. However, when I purchase gas at the local Shamrock, I get no ping. Obviously, not all gas is the same.

 

[mnmridg]

Soo...
4 '06 V8's and one '05 V6...
Any other year V8 gettin a spark knock issue?
I'd hate to think (with the price of gas already) that I will need a can of octane boost with every tank, I'm using 93 octane already.

 

[PewterLS06]

Thanks everyone for your input -- really appreciated. I guess it must be engine knock I'm hearing after all. It sounds like this is a fairly common problem with late model LS V8's.

Out here in Southern California I'm mostly limited to 91 octane fuel, so I guess I'll have to try an octane booster and see if that helps. Does anyone have a suggested brand/type of octane booster fuel additive?

 

[Snowseeker]

I get the same in my 00 3.9

 

[Jayce 1971]

Was thinking maybe it has something to do with the vvt, but snowseeker kinda blew that one out of the water. Verrry high CR on these engines...like 10.5 or 10.75 : 1, being able to retard the timing might be helpful.

 

[2001continental]

My '01 conti does the same thing. BP, shell, Speedway gas = more ping & less mileage. I use Marathon or beleive it or not Giant eagle gas, less to no ping and a couple more miles per gallon. I also use a little acetone in the fuel at fill-ups.