Does this happen to anyone else? I'm not sure whether or not I need to bring this to the dealers attention considering the circumstances it happens under. But nevertheless it seems I'm the only one locally that this happens to.

 

Describe the problem more.

 

During an NLS there is a scratch/squeak (the belt slipping) noise that is very noticeable from the engine bay. It happens predominantly on the 1-2 and 2-3 shifts.

 

Mine makes the same noise I think it's normal

Except I won't ever NLS on tuned mode

 

why not?

 

Dude the other day I was racing david and the same thing I heard chirpping noise when he was shifting but then it faded away as I started pulling away lol jk but ya he asked me the same question if he should take it to the dealer.

What you don't nls

 

i do all the time thats why i was asking him, by the way what you got done to that redline?

 

Yeah, it's very annoying. My truck used to do the same thing when I had the 4L60E built and a shift-kit put in...I had to change out to a gator-back belt to stop it. I'm not entirely sure what about using NLS causes it on the Cobalt as I can shift-quickly normally and it doesn't happen.

Thanks for chiming in though, good to know others experience and not just me.

 

what r ur mods? did you really pull him?

 

That lil sound is normal, mine does it too lol, unless yours is like freakishly loud or something.

 

GM has a long proud history of belt slip between shifts

I hear it all the time, even when not NLS at the drag strip.

Plan on switching to gatorbacks to try and solve mine. I get a lot of knock during shifts, and I sometimes wonder if all that noise isnt helping things. You'd think the knock sensors wouldnt see it as knock, but who knows.

 

I don't have a redline anymore I just keeped the screen name, but I had all the bolt ons on it. I upgraded to the cobalt tc a while back.

 

hm maybe we'll run one some day glad to see another lnf cobalt in socal. there aint nothing like putting a hurting on them turbo honduh's and srt-4's

 

it happens to me a lot usually after 6800 rpm so i stopped using nls

 

Bro why are you taking it to 6800 you make more power nls at 6200 then taking it to 6800 and not nls the whole of nls is that the boost don't drop back down.

 

i win alot of races partly because of nls. if it causes the belt to slip a little so be it.

 

That's exactly my fear. During NLS I noticed I almost always see some KR when NLSing, even on the stock tune, so I just attributed it to being phantom knock. Probably not attributed to the belt, but annoying none the less.

 

Really? I don't see any knock in my NLS, although I am tuned. I don't get this belt slip you guys are talking about either.

 

from my own experience, it doesn't sound like a belt slip but more of a BOV sound underneath the almost from driver side area?

is that the sound?

 

Mines belts, for sure. I never can hear my stock BPV.

Heard enough belt slips in my life to know hehe.

 

Happens to me too.. mine gets kinda loud when its colder outside

 

mine does it as well...i was wondering what the hell it was. It cant be normal tho

 

ok people its not a belt slipping, if ur talking about that ffffft sound from under the car sounds like its under where ur shifter is or in the engine bay, its normal, its the backfire that keeps ur boost up when u use nls. it is not a belt slipping, without that, ur boost would drop back to 0 and u would have no nls.

 

no, its more like a squeeking noise....sounds exactly like a belt slipping......

 

your a ***** i want a rematch i was on stock cam settings

20 redline is in pasadena texas not california.