What is this noise?
12-07-2013, 12:06 PM
#1
What is this noise? Getting this noise when I rev the engine. It started happening right after my last cam swap. I never heard it before that. I figured it was the power steering since you have to pull that on the vette, but it's not. This video was taken with the accessory belts off.
The noise you're listening for is when I rev and it sounds like a mechanical whistling or whining.
The noise you're listening for is when I rev and it sounds like a mechanical whistling or whining.
12-07-2013, 05:14 PM
#2
I don't hear anything out of the ordinary, just a noisy valvetrain which is normal, as long as there are no clunks or rattles etc its fine. Sounds like the typical "sewing machine noise" that many people talk about.
12-07-2013, 06:42 PM
#3
The valvetrain to me sounds perfect for a cammed car with a forged motor
. I wonder if it's a vacuum leak.
12-08-2013, 12:31 AM
#6
The only thing different during this cam swap was the addition of ARP cam and retainer bolts, which wouldn't have anything to do with this.
Could the balancer be making this noise?
12-08-2013, 12:38 AM
#7
Oh, I also did degree the cam in this time, so the oil pump came off for the first time in 30k miles. Obviously the chain came off and was reinstalled as well, which shouldn't matter.
Could a loose timing chain whine like that? My ls2 chain seemed pretty lax.
Could a loose timing chain whine like that? My ls2 chain seemed pretty lax.
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12-08-2013, 09:31 AM
#9
Op, all I hear is normal air suction sounds and your valvetrain. And I agree your valve train sounds plenty healthy. I'm going to guess the video might not be doing your hissing sound justice.
12-08-2013, 10:00 AM
#10
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Also, what style lobes did you have and what lobes did you switch to? Valvetrain mouse cam change dramatically from how hard and fast the exhaust valve is closing. My EPS lobe cam is straight quiet under the hood. My friends with XER lobbed cams have serious under hood valve train noise.
12-08-2013, 01:25 PM
#11
I know the feeling of doom when you hear a new engine noise you can't explain, So I know you won't feel remotely satisfied until you have some type evidence to calm the FEAR; so read on!
IMO, I'm inclined to think that if that sound is from inside the engine it might possibly be the oil pump and pump rotor clearances are off since you did remove and reinstall it. IMO, if it was the slack in the timing chain I think it would have been making the sound before your resent cam swap. I'd go ahead and pull the oil filter off and cut it open to check for metallic shavings, and if it look fine then don't give it another thought unless the sound gets louder. Now if you do find shavings then to make sure it's not just shaving from when the cam was ground I'd drain the oil to, and then check the new oil filter in a couple hundred mile. If you still find shavings then start pulling the cam out to check for cam and/or lifter damage.
IMO, I'm inclined to think that if that sound is from inside the engine it might possibly be the oil pump and pump rotor clearances are off since you did remove and reinstall it. IMO, if it was the slack in the timing chain I think it would have been making the sound before your resent cam swap. I'd go ahead and pull the oil filter off and cut it open to check for metallic shavings, and if it look fine then don't give it another thought unless the sound gets louder. Now if you do find shavings then to make sure it's not just shaving from when the cam was ground I'd drain the oil to, and then check the new oil filter in a couple hundred mile. If you still find shavings then start pulling the cam out to check for cam and/or lifter damage.
Last edited by 99Bluz28; 12-08-2013 at 01:46 PM.
12-08-2013, 02:00 PM
#12
Thanks guys. Def not normal though. It was definitely not there before the cam swap.
Try to ignore the valvetrain noise and listen to the whine type noise. Use the force.
I highly doubt it's something mechanical. The car would have let go by now if it was. I have put about 5000 hard miles on the cam including a few track passes spinning as high as 7200.
If it's ever not 30 out and snowing, I'll use hptuners to hold the idle around 2000 and spray around with carb cleaner. It doesn't make the sound at all at idle, so I feel like that test would be useless unless I keep the rpms up.
Try to ignore the valvetrain noise and listen to the whine type noise
. Use the force.I highly doubt it's something mechanical. The car would have let go by now if it was. I have put about 5000 hard miles on the cam including a few track passes spinning as high as 7200.
If it's ever not 30 out and snowing, I'll use hptuners to hold the idle around 2000 and spray around with carb cleaner. It doesn't make the sound at all at idle, so I feel like that test would be useless unless I keep the rpms up.
12-08-2013, 02:19 PM
#13
Crap I think it might be the oil pump not centered right or something 
https://ls1tech.com/forums/generatio...ine-sound.html
Can you run a motor without the balancer on? That would be a good test I can do before buttoning up the entire motor.
https://ls1tech.com/forums/generatio...ine-sound.html
Can you run a motor without the balancer on? That would be a good test I can do before buttoning up the entire motor.
12-08-2013, 04:49 PM
#18
crazy I just installed a scoggin dicky cam in my lq4 (ground by cammotion) and I been hearing a wine like that. I did not think much of it caus I just assumed it was the alt. and I just never noticed it before. got me wondering now lol. I don't have a ps pump and I never touch my oil pump when I did the swap.
12-08-2013, 04:56 PM
#19
Wow thanks for the idea asking what the cam was....looks like someone else had a whine after a Lunati cam install. Well, this sucks.
https://ls1tech.com/forums/generatio...am-change.html
https://ls1tech.com/forums/generatio...am-change.html