bpalma

iTrader: (1)

Hey everyone. Worried as heck about my 02 Camaro LS1 a4. Shes got 69000 KMs on her right about now. Tonight I took it out for a spin for some fun, and got on it a bunch of times. What really worries me is that in the higher RPMs, the motor seems to make a crackling sound, almost like heavy valvetrain clatter. I went WOT a bunch of times and it did it almost every time, maybe once or twice it didnt do it. I also noticed even going at lower speeds, if I kinda give the throttle a quick stab, I got some crackling to happen as well! During these sounds though the motor pulls super hard, no misfires or hesitations of any sort at all.

The car is BONE stock, and ALL maintenance is up to date on it, including new plugs and wires recently. I use only Mobil 1 Full Syn 5w30. The car has never done this before, although I have not owned it in the cooler weather, and I did go to a gas station out of my area ive never been to before, hoping I didnt get a bad batch of gas or something. I only use 91 octane gas, all the time.

Thoughts on what this possibly could be? Appreciate any help!

dhowdy

iTrader: (2)

I personally can't help you.

But after reading this, I'm pretty sure no one can...

tmdz28

iTrader: (2)

whats wrong with going WOT a few times or all the time , i am sure we are all guilty of that sin

dhowdy

iTrader: (2)

Probably the part where he said the car was making a "crackling" noise...

BayArea ws6

Usually when you hear a cracking sound its time 2 slow down silly.I also like 2 go WOT once in a while,so far i have broken 1 factory rocker arm.Made a loud ticking sound that got faster and louder as i accelerated.15 dollar part, hour of work=$115 .simple/ inexpensive mods like roller rockers and new lifters.(comp or ls7 are fair priced and very reliable )would be a good idea,regardless if you like 2 get a lil crazy here and there.Most likely its something smaller than you think but do not ignore the issue.happy travels....PS I also maintain my car and have less miles roughly 40000 so don't be 2 surprised if something gave out by now.

zachrywd_01TA

Valve Float?

dschmittie1

iTrader: (64)

do it do it at lower rpms and a heavy load or WOT at lower rpms also. Could you be hearing spark knock maybe from some bad gas?

bpalma

iTrader: (1)

Thanks guys, I do deserve the bashing. In my defense, the car is driven to a daycare everyday through the mud. I thought it was dirt and dust flying off the tires and hitting the undercarriage. I really hope its a bad batch of gas I got, the car has NEVER done this before. I plan on babying the car until the tank runs almost dry, and going to my regular gas station.

And yes it does it going low speeds as well, just giving it a quick stab of the throttle, nothing to harsh though. Any other suggestions what this problem could be? I really cant afford to replace an LS1, im a student at the moment.

jimbo98z

iTrader: (3)

Works 60 percent of the time, every time

To the OP: Check to see if it's throwing any codes. Go to a local parts store and they should scan the car for you. Inspection stations can read your codes too. If you're getting knock or anything like that, it will throw a soft code at least.

Mr Incredible

When funny noises occur, slow down, work your way up to them, listen carefully, and think your way to a conclusion. Then apply money as requried.

bpalma

iTrader: (1)

I do have a scanner, I have no codes in the PCM stored or active at all.

Like I said yes I deserve the bashing, im not new to auto mechanics and work in the industry. Its a sound Ive never heard before with this car, or any car for that matter. My previous turbo 3800 valve train would be audibly louder in the cooler weather, but had no issues whatsoever, and did not sound like the way my ls1 did last night. The only reason I attempted to reproduce the sound was I thought the first couple runs was simply lots of dirt/dust shooting off the tires, unfortunately it definitely wasn't that.

I'm hoping its a bad batch of gas, as I honestly don't know what other simple thing it could be. The exhaust does not leak, no heat shields loose or anything like that. Has anyone else had a similar problem to this that was not mechanically related? Really dont feel like replacing springs or lifters at the moment...

$750 L98

iTrader: (7)

Have you checked the belt tensioner? They like to make funny noises when you through WOT or quick throttle blips at them. When they start to go they will bounce around when under stress and make that noise you are mentioning.

bpalma

iTrader: (1)

Hmmm thanks for the suggestion. I did replace the belt tensioner pulley cause the bearing was going out, but not the tensioner itself. It seems to hold tension on the belt good at idle, no unusual sounds or anything, but I guess there is no way to know if its holding good enough at WOT?

RPM WS6

iTrader: (3)

New lifters should not be necessary on a stock cam 40k mile LS1. And it's true that some stock LS1 rockers have come apart, but I wouldn't spend the money to randomly replace those either unless it was needed. The vast majority of stock LS1s will go well past 100k without needing any internal parts like that.

To the OP, you can do an oil change and see if any needle bearings come out, this would point you towards the rocker arms.

Also, can you watch knock retard on your scanner? I'd scan that live/real-time and see what it shows.

Bird

iTrader: (25)

Sounds like detonation is rearing it's ugly head - either a bad batch of gas or, given that you're driving under extremely dirty conditions, the MAF may be fouled - try cleaning it with some MAF cleaner - spray very gently on the elements.

Also might want to check fuel pressure to make sure you're getting enough fuel - clogged filter or weak pump will also cause a lean condition creating pinging.

No matter what, STOP going WOT until you fix this problem - you're hurting your engine every time it happens.

Bird

FST SS

[QUOTE=dschmittie1;13905672]do it do it

BayArea ws6

very true RPM ws6 .factory lifters and rockers shouldn't have 2 be replaced on a 40000 mile stock cam ls1.just a suggestion.By the way I had my lifters upgraded/replaced when i had new cam,heads,ls6 intake etc installed at 28000 miles.couldn't stay stock 4 that long!

bpalma

iTrader: (1)

Thanks for the replies. Unfortunately for some reason my Scanguage2 wont scan KR in realtime on this car, it did on my previous 3800s though. All the filters, including the fuel filter were replaced about one month ago.

I spent time talking to my tuner who took care of my 3800. He told me LS1s have a lot of timing advance from the factory, and any bad batch of gas will allow some pre-ignition to go on. He assured my that N/A motors wont suffer big damage from a couple WOT runs while pre-ignition occurs. First time it ever happend and I didnt hold WOT for long.

Anyway, im hoping this is the problem, gonna wait till this crappy batch of gas is done, and go back to my trusty station. I'll let you know all how it goes, my LS1 is still going strong.

RPM WS6

iTrader: (3)

Another good suggestion. Especially if the car ever had a K&N type filter.

You can either use the cleaner spray mentioned by Bird, or you can use Q-tips and some rubbing alcohol (that's my method).

I've been amazed at some of the problems that have been solved by cleaning an MAF.

bpalma

iTrader: (1)

Thank you for the suggestion. I cleaned the TB and MAF about 1 month ago. They are both spotless. I think I'll write a letter of complaint of something to the sunoco I went to, just pisses me off when they advertise something thats watered down crap. Never had any probs with this car using Shell 91 Vpower. Sunoco FTL.