engine knocking
engine knocking Ok heres the deal i have a 2001 camaro z28 auto, bought it 9 months ago used from a dealer (gm certified used vehicle)with46,500 miles on it....now at 51,200. well today after work one of my co workers happened to be around when i got in my car ... so he starts to llok at it and tells me that he wants to look at the engine bay so i opened the hood and turn the car on, next thing i know he tells me that he hears the engine knocking... i give it some gas and he still hears it , so i go close to the engine bay and heard it my self....so im freaked out now about it ...i came home let the car sit for about 30 min. went back outside to check it out again but i didnt hear it this time my engine is still a bit warm...but no knocking i took it out for a cruise windows down so i could listen for the knocking but none..any ideas???
how serious is it?? (piston slap) till today i had not really payed atte. to any sounds but now, i do recall hearing the noise once or twice before...when i first start the car. am i screwed??
last time i checked smoke kills you....the thing about this is that ...well from my experience it only happened when the engine was cold ...and the noise eventualy went away didnt hear it when cruising through town
TECH Senior Member
Joined: Jan 2004
Posts: 5,798
Likes: 16
From: St.Charles MO
Originally Posted by z28_n_tx
last time i checked smoke kills you....the thing about this is that ...well from my experience it only happened when the engine was cold ...and the noise eventualy went away didnt hear it when cruising through town
Does it kinda sound like a diesel in a way?
Launching!
Joined: Jul 2004
Posts: 235
Likes: 0
From: knoxville tn
yap, my car is doing the same thing too, when its cold ], it almost sound like rod noise, when it warm up, no more noise, it will sound worst if you put hooker or jet hot header. that is just from my experience
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It's normal. A majority of LS1's (if not all) have piston slap. A bunch of articles online if you want to google the subject. Nothing to worry about... nothing you can do about it really. Now my enigne... THIS one's knockin hard! Heheh... get it up to 4K+ and that's all u hear... jeeze... dam 91 octane... dam it to ]-[ell!
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Originally Posted by z28_n_tx
last time i checked smoke kills you....the thing about this is that ...well from my experience it only happened when the engine was cold ...and the noise eventualy went away didnt hear it when cruising through town
I was forsure that I had a busted rocker arm at first, then my mechanic told me I had a bad lifter somewhere.....Then came LS1tech.....a little research, BAM!! piston slap. When my ls1 is cold, click click click click. Once she warms up, voila problem solved
no i dont think it soundlike a diesel.... but today i didnt take it to work.. i got home car was cold turned it on and sure enough there it was that damn noise no too loud but noticeable when hood is open. well i warmed it up to drivining temp. and could still hear it a bit.. it seems that is coming from the drivers side.. so i truned it off again and started it once more..engine warm and still heard it a bit.. gave it some gas heard the noise or slap go faster till it finally went away ...i think ..im so confused now . checked oil everything looks good no warning lights either... what car s and yr models do yall have???
Launching!
Joined: Dec 2004
Posts: 240
Likes: 0
From: New Jersey
Piston slap! If it doesn't burn oil don't worry about it. Loose=Fast. I switched to Amsoil 5W40 from GC 0W30 and my cold piston slap is almost gone. Try a heavier weight oil. 5W30 oils are too thin for the LS1.
Originally Posted by z28_n_tx
no i dont think it soundlike a diesel.... but today i didnt take it to work.. i got home car was cold turned it on and sure enough there it was that damn noise no too loud but noticeable when hood is open. well i warmed it up to drivining temp. and could still hear it a bit.. it seems that is coming from the drivers side.. so i truned it off again and started it once more..engine warm and still heard it a bit.. gave it some gas heard the noise or slap go faster till it finally went away ...i think ..im so confused now . checked oil everything looks good no warning lights either... what car s and yr models do yall have???
Launching!
Joined: Dec 2004
Posts: 240
Likes: 0
From: New Jersey
All Mobile 1 30 weights are too thin. If you feel the need to use Mobile 1, use their 0W40 or the 5W40 T&SUV. The LS1 does better with 40wt oils. Also the 40wt's have a higher HTHS strength, which is better for the engine when you are beating her.
Teching In
Joined: Jul 2004
Posts: 49
Likes: 0
From: Westminster, Ca
It's not piston slap. There is a TSB for the replacement of an O-ring on the oil pump. My car was doing since new and at 32k miles the dealer tore dwon the engine and replaced the piston rings and an o-ring on the oil pump. It fixed the problem but now at 80k miles it's doing it again.
Launching!
Joined: Dec 2004
Posts: 240
Likes: 0
From: New Jersey
I don't think it was your o-ring if they replaced your rings. The rings are what fixed it for a while, but it will always come back. It is piston slap, just deal with it, it is inherent of a short skirt piston design.