C5 piston slap?
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Haha I’m not a vette owner but I do have an ls1 and yes the car cold is the noisest thing ever. Sounds like rod bearing letting go. Plus cammed and longtubes sounds really echo good. I hate piston slap but that noise is only present for less than 5 minutes. If it’s not traceable to rpm speed and metal on metal tapping I wouldn’t be concerned. However lookup ls1 bent push rod clips and compare sound. That noise is 100% the same as a bum lifter from my experience however nice thick oil sometimes shuts a lifter up. If it’s an m6 ever miss a shift or run it hard? Push rod straightness is easy to check. But I think you’re stressing out some. When I put my 42lb injectors in I noticed the pulse of them is louder too and I searched for exhaust leak for an hour before I figured it out lol.
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The car is an m6, ive only had it for a month or so and never missed a shift personally. I did pull the valve covers and make sure no rockers were loose and nothing looked bent. I didn't actually pull the pushrods but they looked fine from what I could see.
Melting Slicks
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From: Virginia
can you post a video? I'm curious to see what yours sounds like
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use the old screwdriver handle in the ear trick and see if you can isolate the noise... on my old f-body trans am the evap solenoid was making a constant tapping that sounded similar, this may not be your issue but just an example
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also have you removed the belts and started car to verify it’s not a pulley or tensioner being weak?
Last edited by Lt1slowerbird; Aug 16, 2018 at 04:30 AM.
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Liftter noise is something most have to live wiht on LSx motors.
Mine started doing it about a month from taking delivery, with 180k sometimes it sounds like its coming apart, other days not so much
Using Dino oil made a huge difference in the noise, plain old 10/30 or 10/40 does the trick. Think all the syn I used was wasted money.
Mine started doing it about a month from taking delivery, with 180k sometimes it sounds like its coming apart, other days not so much
Using Dino oil made a huge difference in the noise, plain old 10/30 or 10/40 does the trick. Think all the syn I used was wasted money.
I can always hear some valve train clatter after starting, and it goes away to the point that I can't hear it in the cabin after a few minutes. But if I stick my head under the hood, it's definitely still there, and it's been that way for as long as I've owned it. *shrug* I do find it interesting that your symptoms were alleviated with heavier dino oil. I tried to same thing all the way to 20W-50 (**** it, I'm in Florida), and if anything that made it worse. Ultimately I decided that it was quietest with the good old synthetic M1 5W-30 that GM told me to use. (I also burn the least of that)
And just FYI FWIW OP (LOL) ... I can't hear what you're hearing, but piston slap is a much different noise and also a very difficult sound to capture. I think the best way to describe is it sounds like a very subtle diesel *clacking*. Like sort of a hollow knocking sound coming from lower in the engine. And this is also very common in engines that use forged pistons. It is not limited to the LS mills.
Last edited by wcsinx; Aug 17, 2018 at 01:13 PM.
Melting Slicks
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From: Virginia
As far as lifter noise in these motors I know alot of ppl say it is normal. What bothers me about mine and why I don't consider it normal is because I am pretty sure mine is just one lifter making noise. I have narrowed it down to coming from cylinder 3 by using a stethoscope. I dont know if the op's situation is the same but mine sounds to only be one lifter.
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Thanks for all the replies fellas. I finally got a chance to make a cold start video for you guys to see what you think. Definitely sounds 90% better once its fully up to temp.
Last edited by Millhousemx; Aug 17, 2018 at 08:03 PM.
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I will try and make a video of it warm tomorrow and post for comparison. Im running 0w40 castrol right now.
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Thanks for all the replies fellas. I finally got a chance to make a cold start video for you guys to see what you think. Definitely sounds 90% better once its fully up to temp.
https://youtu.be/c0Pb-Fnxek0
https://youtu.be/c0Pb-Fnxek0
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Or if you have been using the Castrol Edge 0w-40, try the Castrol Edge 5w-40 next time.
Last edited by JHrinsin; Aug 18, 2018 at 04:57 PM.
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Hood up video each side of engine bay with a little rev. I don’t think your noise is really bad. Should hear my car when cold haha. Sounds horrible but it’s pretty quiet when warm. Got a little bit of valvetrain noise but my lifters are a bit noisey. And imo Castrol and Mobil 1 are both good. Just use good filters. Lt1 I liked the k&n just because of the nut it was easy to remove lol. I may have a video of my car hot. I’ll have to look for you to compare
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Melting Slicks
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Is your motor any quieter with the dino oil compared to synthetic? I may put some dino in to see if it affects the tapping in my motor, just to help confirm it's lifter noise.