Alright my friends redline is making some weird grinding noise, and it has a vacuum leak. Before we got to my house we were at a light and it starting going from 1500rpm-200rpm up and down. Then it died, we sat there for awhile then he turned it back on and it was doing it again so he turned it off. The first time it was doing that we tried to go and when he gave it gas but nothing no revving. Then we waited 5 minutes and it ran somewhat fine so we decided to head down the street to my house on the way we noticed the vacuum leak. My neighbor took a look at it and he said that theres a leak in the CAI, and the grinding noise he said it could possibly be the supercharger anyone have anything like this happen to them? If so what was it or if yall know what it is?

 

so no idea?

 

I had a loud grinding noise. The timing chain tensioner bolt let go and trashed my motor. GM replaced my engine under warranty.

See this thread:
https://www.cobaltss.net/forums/2-0l-lsj-performance-tech-47/really-loud-grinding-noise-coming-engine-39853/

 

how many miles were on it? that would actually be kinda nice to have a brand new motor under warranty if it had alot of miles on it

 

well I had the same problem and gm only replaced the tensioner. lol

 

I noticed the noise with mine at 3k miles. I said something to GM about it at 2 oil changes. I got the "stupid kid" treatment and was told as long as it wasn't throwing a CEL that it was okay. At 24k miles I couldn't stand it anymore and demanded they look at it. By then the damage had been done to the block so they HAD to replace it. I think the reason they only replaced the tensioner in Ljavy17's is because there wasn't any damage to the block.

 

im having the same problem i hooked it up to the scan tool and it said im running to lean at high rpm and to rich at idle i think it has something to do with the cai which is messin with the maf im going to put my maf-t back on today and see if thats the problem ill pm you

 

my car right now only has 10,600 miles on it. so it's not alot at all. today i'm gonna go back over to dragonfires house (i left my car there). hopefully it's nothing bad, i can only hope for the best.