Help LS1 SOUND???
06-13-2005, 08:43 PM
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Help LS1 SOUND??? I just test drove a 01 Z28 70k, I'm buying(considering) and it has a light knocking sound @ around 2-2500rpm. The original owner said he really never heard it or paid attention to it and he changed the oil every 3K and his wife drove it. Anyway it goes away after 2500 and it's quiet all the way upto red line! I revved it up with no load and there was no noise! Is this maybe a normal thing for a LS1? I once rode in a friends Z28 and heard the same growling sound and he said it was normal? Is it possible a trans(M6) noise throw-out bearing, clutch? I like this car alot and although I can perform any required repairs myself, I'm curious about this sound! Sounds like a knock could be pinging or maybe bearing related? Any tips would be greatly appreciated! 
06-14-2005, 01:47 AM
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weird exhaust leak maybe. Also on my car under load while accelerating I can hear a bunch of noise being transfered through my shifter at around the same RPM.
06-14-2005, 02:10 AM
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Could be a spun bearing. I doubt its pinging if its only at that rpms. Sure doesn't sound like valve train noise. My LT1 had that knocking sound and I ended having 4 spun crank bearings. Start the car and put a stick up against the block and put an ear to it. Hard to tell over the internet. If your really interested in the car, I'd take a mechanic to check it out.
06-14-2005, 09:31 AM
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Does it still have the stock shifter? T56 trannys make a lot of noise at certain rpms, so GM addressed that by putting a rubber issolator at the base of the shift lever. A lot of people take that out to get a more sold shifter feel, but you do hear more noises that way.
06-14-2005, 03:32 PM
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I am a MECHANIC! A pretty good one I'd say! Anyway, it sounds like a pinging/knocking sound no doubt, but what throws me off is that it's only @ 2-2500rpm? I revved the engine with no load, and got no noise, if a bearing where spun I'd think on the test drive, 6K shifts, I would have noticed that! The shifter thing is interesting, because as I was driving the car I noticed a H on the shifter looked like the Hurst emblem, and I asked the owner if he ever changed the shifter he said no that's original! Do these cars come with this shifter? Although I tune and build engines, the reason I posted the question on here is because most of you guys have more late model F-body/Y-body experiences than I do, and I'm sure can be of some help. From what I understand these engines also have a oil pump problem? Which I hope to address soon? Thanks for the replies guys!
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06-15-2005, 01:00 PM
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carbon knock sounds like you have carbon on your pistons causing a carbon knock sound. best thing to do is to get some gm top engine cleaner and run i through your intake. should clear it up seen a few here at the dealership with that problem.
06-15-2005, 08:24 PM
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It's very possible this lady lugged around and built up carbon! I'll most likely purchase the car and look into it doesn't sound like a massive problem! Thanks for the reply guys!
