what does this sound like?
12-04-2006, 11:07 AM
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what does this sound like? basically it's sounding like a light tapping noise. it's loudest at warmup and still present, though slightly quieter, while running. the type of noise i am hearing, should this have been a gen 1. small block and not an LS1, is similar to what i would think would be a backed off rocker arm on a solid lifter setup.
i used a mechanic's stethoscope to probe around, seems loudest near the injector rail, not quite so down by the headers or the valve cover.
i'm thinking it could be piston slap, slack in the valvetrain, probably not exhaust leak. i'm a noob since this is my first LS1, though. i won't have time to look at it until saturday, but i'm just trying to get some ideas and how to tell the difference between the symptoms.
oh yeah, 01 z28, 25k miles, hardly driven, prev. owner used dino oil till i got it a couple weeks back. drove home 850 miles fine.
i used a mechanic's stethoscope to probe around, seems loudest near the injector rail, not quite so down by the headers or the valve cover.
i'm thinking it could be piston slap, slack in the valvetrain, probably not exhaust leak. i'm a noob since this is my first LS1, though. i won't have time to look at it until saturday, but i'm just trying to get some ideas and how to tell the difference between the symptoms.
oh yeah, 01 z28, 25k miles, hardly driven, prev. owner used dino oil till i got it a couple weeks back. drove home 850 miles fine.
12-04-2006, 12:00 PM
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yea, i looked up a few things already, just trying something i guess.
i saw that some low mileage cars that rarely get driven develop a tick... most people drive it out, use seafoam, etc... the owner claimed that the gm warranty techs said it was the injectors, but i've never heard them that loud before. i ran two tanks of gas on the way home with seafoam, nothing changed though in terms of injector noise. i took out the owner's cheep dino oil and went mobil 1 + seafoam for a couple hundred miles, then mobil 1 again, drove a while and still no improvement. that's about it so far. i think i'll get under the car and get 100% sure it's not an exhaust leak at the manifolds, and also pull the driver side valve cover and check the pushrods and rocker arms. :shrug:
i saw that some low mileage cars that rarely get driven develop a tick... most people drive it out, use seafoam, etc... the owner claimed that the gm warranty techs said it was the injectors, but i've never heard them that loud before. i ran two tanks of gas on the way home with seafoam, nothing changed though in terms of injector noise. i took out the owner's cheep dino oil and went mobil 1 + seafoam for a couple hundred miles, then mobil 1 again, drove a while and still no improvement. that's about it so far. i think i'll get under the car and get 100% sure it's not an exhaust leak at the manifolds, and also pull the driver side valve cover and check the pushrods and rocker arms. :shrug:
Last edited by burningsquirrels; 12-04-2006 at 12:06 PM.
12-04-2006, 12:28 PM
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i gues the reason it bugs me so much is that the 10-12 fbodies i test drove before all this year sounded fine, and this is the only one that didn't... and pulling up to a drive-thru it's all like, "taptaptaptaptap", and everyone who get sin my car eventually notices and goes "wtf?" lol...
12-04-2006, 12:34 PM
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The ones you test drove probably had thick trash mineral oil in them instead of smooth flowing deliciously refreshing synthetic. The thick oil probably helped to mask the noises.
