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I finally got around to making a quick video of the engine knock sound I'm hearing. It doesn't sound much like a rod knock or lifter tap and it isn't really present at idle. Before I pay a mechanic $150/hr to listen or delve into replacing rods, springs or anything else I'm trying to figure out what the noise might be. You can only hear it when I rev the motor a bit and it sounds more like a hollow air escaping sound than a dense knock or light tap... Hopefully I'm not just crazy and hearing things .The video is of me next to a wall because that's the only way to really hear it. Any ideas what it could be? Sorry for the video quality, I recorded it on my iphone so you might have to turn up the volume a little bit.
Edit: I tried embedding the video from youtube but it isn't showing up... maybe I screwed something up. Anyway, I posted the link to the video and if anyone can help me figure out how to embed it I'll edit the post.
Thanks for the help guys
Hard to say, can't really hear anything wrong, do hear some whooshing. Try recording away from wall, with phone outside car. The wall reflects too much sound.
Hard to say, can't really hear anything wrong, do hear some whooshing. Try recording away from wall, with phone outside car. The wall reflects too much sound.
List your mods, like headers etc.
Thanks for the reply - I guess whooshing is a better way to describe the sound. I'll record a video tomorrow when my buddy is over and he can stand next to the car and record.
Mods are headers, x-pipe, blackwing, PP throttle body, mild 212/218 .522/.529 cam, corsa indy pace car exhaust, B&M ripper short throw and a Spec stage II clutch.
Hard to say, can't really hear anything wrong, do hear some whooshing. Try recording away from wall, with phone outside car. The wall reflects too much sound.
List your mods, like headers etc.
Here is a screenshot of a spreadsheet I made from all the previous owner's receipts - this was all done to the car when I got it. I've only had it about two months and it desperately needs a tune (after accelerating hard on the highway I get a lot of cam surging from about 400-1200 RPM in neutral when coasting) and just by the smell and my avg mpg I can tell it's running a bit rich. I don't think the other owner ever had it properly dyno tuned.
I would get it tuned then, and it may take care of issue too, and they may be able to ID noise. Probably has something to do with the mods, could it be the intake filter vacuum sound? So hard to tell on recordings.
Well, looks like I'm headed to the shop. I just did the LS6 intake swap but the car is still making that whooshing/tapping noise that increases with RPM. Sounds a bit like valvetrain noise but I can't quite figure it out. I'm going to get it dyno tuned at 21st Century Muscle Cars tomorrow afternoon so if something's knocking, they'll be able to tell. I'll update with the results.
From: Piedmont, SC Currently Own: 99 Nassau blue FRC. Previously Owned: 84,95,98 Indy Pace,01 Z06
With headers you will hear alot more valve train noise then you did with stock manifolds. Headers are thin wall while the stock manifolds are thick. This may or may not be what you are hearing, but I know when I added headers it amplified the valve train noise.
Well, the good news is I don't have a knock... The bad news is what I was hearing was detonation. Luckily, I got it tuned correctly and the car drives like a totally different machine. I don't know if I can say that I picked up a ton of rwhp, but the power is definitely smoother and more consistent over my entire RPM band (it keeps me in my seat instead of just throwing me back); whereas before it was much more a peak and valley feeing. Now, my torque curve is nearly flat from 2,500-6,400 RPM. All in all, the car put down 352 rwhp and 346 rwtq - I can't say I'm happy with the power, but I guess it could be worse. At least now I can get on it without worrying about blowing up my motor. Before the tune the guys said it was running very rich and with a huge timing advance, which was causing the detonation. If anything, glad I got it fixed. I attached some pictures of the dyno graph if you guys are interested.
Engine Noise With Video - Help Diagnosing
.The video is of me next to a wall because that's the only way to really hear it. Any ideas what it could be? Sorry for the video quality, I recorded it on my iphone so you might have to turn up the volume a little bit. 
