Intermittent Metal Noise
 

I have been hearing a metallic scraping noise for awhile. I haven’t posted because I have been trying to isolate it, but no luck. The noise only happens when I’m driving, I will come to a stop and it will continue. But if I leave it in N and get out to listen it doesn’t make the noise.

I have gone from thinking it was brakes (ruled out when it continues at a stop), to thinking it is a loose bolt on something in the drive belt. It comes and it goes and I haven’t found a commonality of when the noise happens.

I do know this, when the noise is happening and I hit a bump the noise clanks.

Car is running fine. Recent project is install of AGP dual fuel pump about 500 miles on it. Installed LSA 5,000 miles ago. Rear cradle bushings 500 miles ago.

Been busy figuring out boost line issue (separate thread) that I haven’t dealt with this. But now that I am sure my boost line issue isn’t major I am more concerned with this noise.

Anyone had this? Ideas on how to isolate/rule things out?

I tried to record the noise, but you can’t really hear it on the recording.

First thing to check IMO is exhaust shields under the car. It can occur over time and happens intermittently when engine is running, but can change over bumps.
Is it related to wheel speed?

The noise will persist at a stop light. When I did my fuel pump I did drop both heat shields above the drive shaft. I didn’t reinstall one because I couldn’t get it back in quite right above my drive shaft loop. Worth getting under there and checking, good idea.

The noise seems to be coming from the engine bay. But since I can only hear it while driving it is hard to tell for sure. My car hypochondria is making think bolts are loose somewhere. I check my belt drive this morning and everything was tight.

Got a recording today where you can at least hear what is happening. The noise has gotten louder and changed tone. So what ever it is it seems to be progressing.

Apparently I can’t attach an audio.

I have been thinking about your suggestion. This makes sense to me now, I think the heat shield is hitting the driveshaft. What threw me off was when it happens at a stop. But the driveshaft spins in neutral so now I get it. Climbing under there this weekend to explore. Thanks again for the comment.

What? How can your drive shaft spin on neutral?? The car would be moving if the ds is spinning..lol. Mine doesn't spin in neutral or park.. Only when the car is in gear will it spin.

I hear the noise at a stop. I googled it, lol. I am trying to figure out the noise and thought I had it!

What spins under there that could be hitting something while driving and at a stop? The noise is driving me crazy!

So, the noise is there when the driveline is engaged, correct? If in park or neutral, the noise goes away?

Is you Camaro a stick or an auto?? If an auto check your flex plate bolts, maybe one came loose and is hitting something in the bell housing, if a stick check your throw-out bearing and such.

It is both, but not ever when I am in the garage with the hood open!

It’s manual, how do I check the throw out bearing?

I'm not to sure on that one as I have an auto, was just a suggestion and hopefully someone will chime in that knows. I know in my "old school" Muncie you'd check it with the car running in nuetral and by slightly depressing the clutch pedal and the noise would go away, then when you let off the pedal it would come back, not sure about these hydrolic clutches. Good luck.:thumbup:

I watched a really good generic video on manual transmission noises. Granted the M6 may be different from what he showed. The throw out bearing would be affected by clutch use and that doesn’t seem to be the issue because the noise was unaffected by the clutch going in or out. Also, the noise in 4th would mean something, but that wasn’t it. Then going in neutral at 40 mph, which didn’t do anything either.

I did figure out that above 40 the noise doesn’t really occur. It is more in stop and start situations. It is definitely something that spins whether I am in gear or neutral, moving and at a stop. I am leaning transmission, but not sure what?

I have a similar sound but looking more forward a vaccum related issue (another thread, long story)

Does it sound like two metal disks spinning together making a sometimes quiet, sometimes loud, metallic whirring? Not like a knock, but just a rotational sort-of-grinding noise? Kind of like a diesel engines sound but milder. With the high pitched portion

So I took it to a guy here, found a good mechanic by the way, we put it up on the lift to listen to it while it was running. Found the noise in 5 minutes.

The drive shaft loop was barely touching the exhaust pipes. The echo on the pipe was sending noise everywhere.

So...what had happened was...when I dropped my tank I had to drop the pipes and driveshaft. When I reinstalled the drive shaft loop I noticed two weird ground down washer that sat in between the plates on the bottom of the loop. I wanted the plates to be flush for strength. Turns out the the previous owner knew what he was doing. The washers put the loop at just the right angle to keep the top of the loop from touching the pipes.

Happy ending to the story that cost nothing to fix. The new mechanic is a transmission guy. We got to talking about a double clutch and now I am thinking about that.

Wow that' cool!! So glad you got that figured out, for free!! lol.

Yeah, I was beginning to think it was major. Always great when it is something easy.

:happyanim::clap::grouphug: