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LS1 newbie here!
My 2001 Corvette with 53,000 Miles has developed a knocking and unsure what im hearing. Starts great but after a minute or 2 of idling the knocking becomes more noticable as the car warms up, Oil pressure reads good as 30-32PSI at 700 Idle and 40-46psi driving at 1500-2000. I did an oil change and noticed some sparkles in the plastic oil catch pan, but when i cut open the filter it looked super clean, i drained a bit of oil couple days after the oil change and noticed smaller ammount of sparkles yet still there. Im sending in a sample to blackStone Oil but would still like to see if anyone can help! No check engine lights are on and when i took off the valve covers there was no sign of any sparkles or damage to my understanding. Videos and pictures will attached! The noise is very noticable when coming down in rpms and is very loud around 1000-1500 RPMS or idle.
Not a rod knock, I would pull your valve covers and check your rocker arms. Might have lost some needle bearings. Could have a failed lifter too. It's definitely a valvetrain issue, the sound is too high pitched to be in the bottom end.
I agree with the above post, definitely doesn't sound like a rod. Like stated above pull the valve covers and and check rockers if that's not it then keep coming until you find the problem. If it weren't that then I'd check the valve springs, I had a valve spring making a similar noise. The guy I bought the heads from used the wrong retainer clips and a few of my inner springs were broken and causing the noise. I couldn't see it from common eye but when I sent the heads to a machine shop they found the issue and I went ahead and put ls7 lifters in it while I had it apart and all is good now.
I agree with the above post, definitely doesn't sound like a rod. Like stated above pull the valve covers and and check rockers if that's not it then keep coming until you find the problem. If it weren't that then I'd check the valve springs, I had a valve spring making a similar noise. The guy I bought the heads from used the wrong retainer clips and a few of my inner springs were broken and causing the noise. I couldn't see it from common eye but when I sent the heads to a machine shop they found the issue and I went ahead and put ls7 lifters in it while I had it apart and all is good now.
Funny you say that, I had a valve spring break at idle in my Formula and it did sound a lot like that, but there's no way mine would have even driven - the valve was being held up by the flat wound damper. I'm just glad it happened at idle or I'd have been buying an engine. That's why I hesitated to say a broken valve spring, because of the single beehives LS1s have stock. If one breaks, it's likely to drop a valve. Definitely possible, however.
Funny you say that, I had a valve spring break at idle in my Formula and it did sound a lot like that, but there's no way mine would have even driven - the valve was being held up by the flat wound damper. I'm just glad it happened at idle or I'd have been buying an engine. That's why I hesitated to say a broken valve spring, because of the single beehives LS1s have stock. If one breaks, it's likely to drop a valve. Definitely possible, however.
so I was actually in Tampa Florida working when it happened to me and I live in Louisiana so I was 11 hours from home when it happened. i drove it all the way home like that and pulled it apart once i got home. I guess I got lucky because the valves were still functioning OK, I pulled the valve covers when I got home and from the outside it looked fine because the outer springs were still moving like Normal but when I put a scope on it I could tell the sound was coming from by the valves so I went ahead and pulled the heads considering the guy I use for my head work gives me really good prices so it was easier to just send him the heads then for me to mess with it and that's when he figured out that the guy that I bought those heads from used the wrong clips with the dual springs
That's a good idea for the OP. Get a mechanic's stethoscope and listen around the engine at different points to determine where the sound is coming from. You can get one for like $10 at Harbor Freight.
02-27-2024, 12:22 AM
LS1 Engine knock? Lifters? Rod? 
