piston slap?
#1
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i wasnt sure where to put this so, i put it here lol. Well as some of you know my D1SC will b here tomorrow, and will be going in the car within the month. Maybe.... I noticed here lately that when my car is cold (first start) i can here a knocking sound coming from the engine. I get down on teh ground and can hear it pretty good. Its making me nervous. But after the car warms up, it quiets up quite a bit, to where you cant really hear it anymore. Now im getting ready to boost my car...111k miles, stock bottom, mods in sig. Gonna run 7-8psi with a 4.50 blower pulley. You think im just worrying about nothing? O and btw, Im due for an oil change and im about a quart low. I use 10w30 Mobile 1 Full synthetic.
#2
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i wasnt sure where to put this so, i put it here lol. Well as some of you know my D1SC will b here tomorrow, and will be going in the car within the month. Maybe.... I noticed here lately that when my car is cold (first start) i can here a knocking sound coming from the engine. I get down on teh ground and can hear it pretty good. Its making me nervous. But after the car warms up, it quiets up quite a bit, to where you cant really hear it anymore. Now im getting ready to boost my car...111k miles, stock bottom, mods in sig. Gonna run 7-8psi with a 4.50 blower pulley. You think im just worrying about nothing? O and btw, Im due for an oil change and im about a quart low. I use 10w30 Mobile 1 Full synthetic.
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Without actually hearing it it's hard to say what it is exactly. But from my experience it's probably the lifters. I had the same issue as you it would tick pretty good when cold but once I put my cam in it go t really bad! Like so bad I stopped driving it until i had enough money to put new heads and lifters on it now we are all good! I would just put the d1sc on and just hope for the best but if it gets worse just plan on either swapping out parts in the ls1 or build a new forged motor.
#4
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its not valvetrain. Its a solid knock that i hear for a few minutes when the car is completely cold and when it searches for idle for few cuz of the cam. Bob at brutespeed said my mileage shouldnt be a problem under low boost. just wanna make sure this knock isnt major.
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if its piston slap then i cant see that motor lasting too long adding a d1sc and the current mileage i would hold off unless u have the money to fix it its not just slapping on a supercharger that u have to think about it is everything else that comes into play rear end ,clutch etc....
#10
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My 35K miles LS1 sounds like a diesel for the first minute it is fired. Piston slap. There was even a website for people who organized to complain to GM. I wrote them a letter and they gave me a 5 year/100k mile warranty on the motor. That was a number of years back and I have had no problems except being embarrassed by the noise.
#11
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little update guys. I dont think its a rod bearing or piston slap. I got my hands on a mechanics stethoscope today, and me and another guy started listening to it. I put the probe on the passenger side valve cover towards the rear and could hear a definite loud ticking noise. Then i moved the probe to the front of the same valve cover and i could still here it, but it wasnt as loud or pronounced like it was in the rear of the cover. then i layed on the ground and put the probe on the back of the oil pan and the front and had the guy rev the car up for me. I didnt hear any ticking noise down there in either position. I would assume if it was a rod knocking, or piston slap, id def hear it through the stethoscope touching the oil pan...Am i wrong? so apparently its valve train noise, now i just gotta figure out what the hell is ticking..... any ideas?