Hey guys.

After some searching around I've found alot of things that could be a knock noise. I'm hoping that mine isn't anything major.

I noticed the knock this past Sunday. I had taken my Brother in Law out for a ride earlier and got on it pretty good. I didn't get to redline. Maybe into the yellow but that's it. Stupid me didn't change the craptastic oil that was in it after I drove the car home from picking up.

Since then the car has had an oil change with M1 5w-30, coolant flush, and tranny fluid changed. I have also added a can of Seafoam to the gas tank.

I noticed the noise up top first but after taking the video just now, you can hear it from the bottom as well. Both sides. The noise starts about 30 seconds after starting the car and warming up. It stays pretty constant after that. The frequency of the knock changes with engine speed.

I really hope I didn't hurt it. I don't have the money for major repair work and I'm honestly not confident in doing this myself. I don't have the tools for one thing. Could this also be related to my weird smoking problem? Heres a link to that thread

https://ls1tech.com/forums/general-maintenance-repairs/897605-help-s-smoking.html

and a link to the noise.

http://s255.photobucket.com/albums/h...t=100_1502.flv

The idle is also very rough (to me at least). No check engine light and seems to have a bit of a "dead" spot when I'm accelerating a little harder. Probably something a general tune up would fix. Thoughts?

 

i cant really make out the frequency and tone of the knock. how fast does it happen in respect to the engine speed?

 

It seem to pretty much match the engine speed. Definetly a knock or a tap. To low to be a tick.

 

TTT

2002 CETA Knocks at IDLE
Sounds exactly like this....

Anyone have the same problem?

Also, no its not the piston slap...

 

Sounds like the lifter tap that my truck has.

 

spun rod or main bearing..

 

Pull out the pushrods and make sure they're straight as an arrow.

 

-Lifter Tap
-Spun bearing/Rod
-Bent Push rod


I hope and believe its just a push rod...

Any other LS1's ahve thisproblem?

Thanks

 

Still got the factory cats?

Is it louder on the bottom or top? If up top it's probably valvetrain.

 

Top....Really loud...almost drowns out the motor. Completly stock car 30k miles

 

I have a similar noise that you are describing with my Trans Am, I had taken the valve covers off, inspected the pushrods and rocker arms did a compression test on all cylinders, and every one of those things checked out ok. From the inside of the car it actually sounded like a heatshield rattling around.

I'm going to pull the heads off sometime this weekend (if I have time; work owns me) and see if it is a collapsed lifter or a bent valve. If that checks out then its time for an upgrade! Also from what I have read, alot of the 6-Speed cars have similar noises due to over-revving and miss shifts, resulting in valvetrain issues. (bent pushrods, bent valves etc.)

Is this sound similar to what you are describing? This is the noise from my car... *disclaimer you need quicktime to view the video*

http://media.putfile.com/0718081435

-Rick