Okay guys, it started happening after I installed my 2.8" pulley. Whenever I punch it in 1st gear I get this really weir noise coming from the engine, is like metals rattling agaisnt each other, like a grinding sound. I only get it in first gear in the high RPMs, also sometimes when the car is cold I get this sound too when I punch it in second gear, towards the last RPMs. WHat do you guys think this is.

 

did you make sure everything was tight and the belt was sitting on there the right way? I have never heard of this before just some thoughts.

 

Not sure.. Was the pulley put on straight?

 

I believe the belt is in the right way, I installed it myself, Im with the stock belt,

 

i dont think it has anthing to do with your pulley, i do not have a pulley and im getting the same rattle, my friend said it sounds like bolts in a tin can. i was thinking about going to the dealer, but i just cant find time atleast until scool getts out.

 

Maybe that stock belt has something to do with it!

 

a 2.8 pulley and stock belt is asking for trouble.

 

New Member Here, Great Site

I'v only had my SS/SC Cobalt for one day, put maybe 10 miles on it and have heard that same type of sound coming from under the hood. Gave it a couple of slow revs and the noise went away. Not sure but I to thought it was coming from the Blower. The Blower that I put on my Silverado has that sound all the time and Whipple said not to worry about it. But when the Cobalt does it from time to time it seems to me somethings not right! Will have to ask the service department about it.

 

It couldn't be the fins in the supercharger could it? maybe they were damaged

 

I think I might be getting the same noise that you have.

 

Please check back here when u take it to the dealer, I cant take it since im modded to the booty.

 

I'm afraid of taking my car in as well for warranty work....Just recently I had the P0300 code thrown which is a cylinder misfire....Not a good sign....

 

are u still on the stock spark plugs.. maybe you need new ones. i put the ngk's on



as far as the supercharger grinding.. being with a 2.8" pulley and stock belt that's all that it would be was the belt slipping so it couldn't be that i wouldn't think... weird...

 

I had a very similar noise and I think it turned out to be my K&N intake. I adjusted it so that it wasn't resting on the inner plastic fendor well. The adjustment also gave it more clearence through the hole it goes through to get down into the fender. Haven't had the noise since. And it did sound like bolts in a tin can too.

fixed last sentence ^ didn't make sense. lol but that seemed to fix the problem for me man.

 

HOLLLY CRAP! It could deffinetly be that man! Because My Fujita fit sooo tight in that whole, now with more power the engine makes more vibrations when I nail it, of course witht he added TQ that we have in 1st gear this causes the engine to vibrate crazy and the intake is probably hitting the metal like crazy. That sounds very veyr reasonable. I might check into that.

 

What about the coupler or a needle bearing? Perhaps the boost bypass valve?
Alot of roots type blowers makes this noise and i have always been told its fine.

 

What about the exhaust ball bearings?

 

I haven't heard the noise again yet. So not sure what's going on. If it does it again I'll take it in to get checked out.

I do have another weird issue every once in awhile when the engine comes down to a idle after pushing in the clutch in the RPMs bounce around alot. They like go from 1000 down to 300 and back up to a 1000. It does this about 4 or 5 times then finally smooths out. Anybody had this problem.

 

Could be the injector, on my buddys srt. It threw the same code and went into limp mode. Turned out to be a bad injector!!!!! Keep that it mind!!!

 

take your car in and get it reflashed. a lot of people have had this same problem. i did also.

 

Not really if u have a tensioner and make sure the belt is tight I am running a 2.7 and it was a pain in the a*s to get the belt on but its tight and I haven’t heard any grinding.

 

Mine is definately in the supercharger

 

I heard a slight grinding in mine as well. The service manager brought a brand new SS/SC from the lot into the service bay to compare side by side. They both made the same sound. It was funny looking, the tech was putting a stethoscope on both of the car's superchargers. It's probably normal and your over reacting just as I was.

 

It is most likely the composite couplers that mate the snout to the gearset that keps the rotors properly timed. There is usually some play in the coupler that causes this rattling sound...especially when the engine is at idle/no load.

-P

 

I heard a marble noise from the S/C when i went to the 2.8" also. This is normal don't worry. I put about 4k miles on it and it still runs good.