Evinny

Hey Guys,

My car has 58k on it. 2002 SS LS1 M6 Only mods are full exhaust and Tune. I was going to sell it but decided to keep it bc I just love the car. It starts and runs great, is super fast etc...But around 4k and 5k when getting on it I hear a strange metalic clicking / rattling sound. Anyone ever had anything like this?

I know that isn't much to go off just thought I'd throw it out there.

Thanks

Darth_V8r

iTrader: (4)

Is it in the engine compartment? Underneath the car? Only happens under high load?

If it sounds like you're shaking a spray paint can really fast, it would point to spark knock

shadowfirep

really hard to tell off just this, but maybe rocker arms tapping while at high rpm?

gagliano7

Exhaust touching somewhere?

Evinny

I do have slight exhaust leaks and rattles occasionally but this is different. definitely coming from the engine. It does sound like a really fast spray can shaking. I recently heard it at very low RMPS as well. if im cruising along around 1k-1.5k rpms and put it under a load it doe sit as well. Im going to see if I can capture it on video today so you guys can hear it.

I noticed it for the first time right after I had PBJ tune it. think that could be related?

Evinny

Yes it is under heavy load

SuperSport01

I bet its spark knock. Maybe your tune isn't so great... or if the car sits around alot it could be your fuel has gone bad.

Evinny

I drive it often. Im thinking the same. Thank you guys for your input. I will be going to have the tune check asap

Darth_V8r

iTrader: (4)

My stock tune did the same thing when my car was stock. It knocked really bad from 1500-2000 rpm under load. I thought a previous owner had dumped a box tune in it - like superchips or something.

While you're looking at spark, check your fuel trims on your scanner. You may need to add some fuel to your higher load cells in the 1200-2000 columns

Another helpful thing might be to drop your PE triggers. My tuner set mine at 23% throttle vs 64% throttle from the factory in the lower RPMs.