Fire-formula 93

iTrader: (1)

I have noticed lately that my car sort of sounds like it is breaking up at higher RPMs at WOT. The sound is very hard to describe but it is kind of like a slight popping and it is kind of raspy. My LT1 made this exact same noise when it was missing but I never fixed the problem in it.

It seems to be running good until WOT. It pulls hard and doesnt SEEM to hesitate but it definitely does not sound normal. With windows down it is very noticeable.

I have yet to pull any of the plugs though. I will have time soon.

Any ideas?

formula001

iTrader: (1)

Detonation maybe.

Z28LS1camaroguy

iTrader: (3)

have any codes or an SES light???? b.c if it was a miss fire it would blink and wouldnt it do the same with detonation.

Fire-formula 93

iTrader: (1)

I was thinking the same (detonation). I have never heard detonation before so I cant be sure. I run 93 octane 100% of the time! What would cause detonation on this car with only lid, K&N and flowmaster muffler?

No check engine lights either.

Sunset'01Z

iTrader: (10)

does it sound like popcorn popping? i think i may have the same problem.. i cant hear it with the windows down though, all i hear is exhaust and wind. with the windows up i hear a faint crackling though. car still pulls like a son of a bitch though.

ChocoTaco369

it's just rasp i'm pretty sure. my exhaust is the dual/dual so there isn't any rasp really, but if i go WOT, when it shifts from 1 to 2 it makes a sound like when a bb hits a soda can. it's just from uneven y pipe lengths from what i've heard, either that or the natural raspiness of an aluminum engine.

Fire-formula 93

iTrader: (1)

EXACTLY! Sounds just like popcorn popping, crackling is a good word too. It is coming from the front of the car so I dont think the exhaust has anything to do with it. Unless it may have something to do with an exhaust manifold leak.

Sunset'01Z

iTrader: (10)

must be that damn good looking paint job

well my car runs great (cept for my asp pulley at the moment.. ) so i really dont think its too much of a problem. i've put 20k fairly hard driven miles on my car in a year and a half so it's probably something in the engine making noise that is supposed to make noise. and yes, aluminum blocks to resonate more noise than iron blocks do.

Fire-formula 93

iTrader: (1)

Yeah it was my favorite color so when I found one, I snatched it. It now has Charcoal Metallic Blackbird stripes and looks even better!

What concerns me about the noise is that my LT1 did it also. So it cant be just the alluminum block problem. I am going to do a tune up soon anyway so maybe it will help.

'Trust'

iTrader: (24)

How many miles are on the car? How does it sound at idle normal or off? Whats your oil level like? I'd check your plugs etc. alot of times with just a cracked plug the car can miss and the computer won't pick it up unless its severe enough, it can run absolutely fine with daily driving with a cracked plug, but once you get on it, it begins to show. That'd be my first check, then go from there.

Fire-formula 93

iTrader: (1)

Thanks.

It runs absolutely amazing. No hesitating at all. It has the traditional LS1 shake and shimmy at idle but that is it. MSD wires are on the car already. Like that when I bought it.

Oil just changed, put in M1 0w-40. Valvetrain noisy as hell so I will try another oil next time.

And car has 56,000 miles but it seems to be increasing very quickly

'Trust'

iTrader: (24)

Yea, I'm starting to steer away from M1 brand, if I can find some German Castrol I'll be using that. As for your problem, my bet is on a cracked plug, BUT if the car still pulls well uptop it may be nothing but valvetrain since you mentioned it is noticably noiser than before with that oil.

ohsofast

iTrader: (6)

It could be bad gas, gas station tank has too much condensation. Have you tried 93 at other gas stations.

ChocoTaco369

put a whole can of seafoam in your gas tank and run another can through your oil and through the brake booster, half a can in your oil (make sure to change your oil 250 miles later, no more than 500 miles), the other half through the booster. that'll flush out your entire car. if something is clogged, that'll break it loose no doubt and if it's water in the gas tank, that'll dry it right up. good stuff and it's 5 bucks a can. i bet you'll pick up 1-2mpg while you're at it

Z28LS1camaroguy

iTrader: (3)

dont you have to change out the spark plugs if you do the seafoam thing????

ChocoTaco369

no way, not at all. whoever told you that is full of

jpat1023

I have the same problem and have been searching this board extensively to try and find out what it is and the only answer I have come up with is this: a lot of people have this problem, no one knows exactly what it is, it usually doesn't effect performance, and we don't know how to fix it (except seafoam, sometimes).

However, wether it hurts performance or not, I would do anything to get rid of it; it sounds horrible(to me, i doubt most people would notice it), and i think the jury is still out on it hurting performance.

I hope someone can enlighten us...

Fire-formula 93

iTrader: (1)

So 1 can of seafoam in the gastank and 1 1/2 cans of seafoam each in the brake booster and oil right? I will utilize the search function I guess. Thanks.

Z28LS1camaroguy

iTrader: (3)

isnt there only one brake booster hose???, im gonna prolly do the seafoam thing the day i do my oil change. seafoam it and then put in the german castrol 0w-30 that i finally found, i want to see if this oil is as great as everyone says it is.

ChocoTaco369

go to the gas station when your tank is almost empty. dump in a whole can of seafoam while empty. then fill up.

take another can of seafoam. divide it in half.

take the first half and suck about 2/3 of that SLOWLY into the brake booster. don't let the car stall out (make sure your car is warmed up first, don't do this on an immediate cold start). when i did this, i put a small funnel into the brake booster hose and slowly poured it in around an ounce at a time. once that is gone, quickly pour the other 1/3 into the brake booster so the car stalls. if it doesn't stall out, it's fine, just quickly turn off the engine. let it sit for at LEAST 15 mins. start the car up. let it idle for 10 minutes. if it doesn't smoke a lot, GENTLY tap the gas pedal for less than a second. one quick pump up to say, 1300rpms. no need to mash it. a very very gentle bump. that should jumpstart the smoking.

after it has idled for 10 minutes, take her out for hard drive i.e. you better mash this thing a few times. bummer drive for a couple miles like this.

with the last half a can of seafoam, dump it into your ADD OIL tube (directly into the crank case where you add your oil when you change your oil). preferrably dump it in your oil AFTER the engine has sat for a while and cooled off. it's not great to dump room temp seafoam into 200 degree engine oil. it's not the best thing for your valve springs. i'd wait til the next morning to do this part. run the seafoam in your oil for roughly 250 miles, then change the oil. do NOT run it for more than 500 miles with that seafoam in it. your oil will start to gunk up because it frees a LOT of sludge. hell, you may even wanna change it after 100 miles if your oil is black when you change it.

there's my detailed writeup on seafoam. if you have any more questions, PM me or let me know in this thread.