Knocking sound with VID.

**casperss** · 09-04-2008, 02:49 PM

Ok listen to this vid and tell me what could this rattling, knocking noise be.
the engine is at operating temp so piston slap should not be the issue or should it? The oil psi is fine and oh BTW sorry for the quality of the vid I used my sony camera.

**Wesman** · 09-04-2008, 03:54 PM

Almost sounds like a valvetrain noise, but its hard to tell with the static sound in the background.

First thing I would do is pull the valve covers and check all the rockers for looseness or damage, as well as the pushrods to make sure none are bent. Check the valvetrings too, and ensure that none are broken.

I think you will find the problem in the top end of the motor. Usually a rod knock is a much deeper knocking sound that what your video shows, and it doesn't sound like piston slap to me either.

**casperss** · 09-04-2008, 04:10 PM

Originally Posted by Wesman

Almost sounds like a valvetrain noise, but its hard to tell with the static sound in the background.

First thing I would do is pull the valve covers and check all the rockers for looseness or damage, as well as the pushrods to make sure none are bent. Check the valvetrings too, and ensure that none are broken.

I think you will find the problem in the top end of the motor. Usually a rod knock is a much deeper knocking sound that what your video shows, and it doesn't sound like piston slap to me either.

Well thats what I was hoping. Ok i have never had an LS1 apart so is there anything I need to know before I get started? Like will i need any new gaskets. Also are there any good links around to show me the valve lash #s and such things of that manor I will need to know. Thanks

**0rion** · 09-04-2008, 04:57 PM

I agree that it sounds like a valvetrain issue to me...pushrod or lifter. Go to ls1howto.com and look at their cam/heads install guide and you should be able to piece together enough out of that to do the job. You won't need valve cover gaskets and you won't have to set valve lash. Banged the limiter recently?

**Wesman** · 09-04-2008, 05:41 PM

Originally Posted by casperss

Well thats what I was hoping. Ok i have never had an LS1 apart so is there anything I need to know before I get started? Like will i need any new gaskets. Also are there any good links around to show me the valve lash #s and such things of that manor I will need to know. Thanks

Not really. The valvetrain design on the LS motors is pretty simple and straightforward.

As Orion was saying, valve cover gaskets are reuseable as long as you don't damage them during removal, and the valves are self adjusting, so there is no lash adjustment. Just torque them down and you're set.

**ggino85** · 09-04-2008, 07:03 PM

my car makes the same noise but its louder from under the car, i didnt notice it was louder from under the car till the other day when i had it on a lift, u should find a way to get yours up and see. oh and i have pulled my valve covers and checked the springs, rockers and pushrods and everything was ok. still cant figure out what the hell the noise is

**casperss** · 09-04-2008, 08:04 PM

Originally Posted by 0rion

I agree that it sounds like a valvetrain issue to me...pushrod or lifter. Go to ls1howto.com and look at their cam/heads install guide and you should be able to piece together enough out of that to do the job. You won't need valve cover gaskets and you won't have to set valve lash. Banged the limiter recently?

Maybe... and thanks for the info. Ok I'll admit it i shoved it back in first and not third one time but it was already making the noise prior to that oops. so I'm sure that that didn't help any.

**CARHAULIN** · 09-09-2008, 05:37 PM

Mine is making same noise,if i fugure it out i will
let you know , going to dig into tommorrow

**david_viny** · 09-09-2008, 06:03 PM

Mine too

. I almost wonder if mines somehow the clutch though, I Know mines on its last leg and the noise does seem louder from underneath car.

Mine sounds EXACTLY like the vid, I'm just going to run it till winter and maybe look into it then after I replace the clutch. Hopefully it’s just the clutch…

**wultdat** · 09-09-2008, 08:07 PM

Mine makes a noise like that too :<

**ggino85** · 09-10-2008, 03:24 PM

ok the tick/knock in my car doesnt change with the clutch in or out. so i bought a stethascope and i think i narrowed the sound down to the passenger side cylinder head. could a lifter or sticky/bent valve make that much noise?? any suggestions guys, im CLUELESS!!!!!

**CARHAULIN** · 09-10-2008, 04:26 PM

Talked to a couple gm techs today at a couple
dealers when at work today.they said its
a common problem for lifters to stick on theses
motors,and for bearings to go out on rocker arms.

There sugestions 1 to take off valve covers and
check for bad rollers on arms or broken springs
check lifters by pushing on rod end of rocker with
something like hammer handle and listen for noise
to go away then you found the bad one.
2 was to drain your oil,put in 5 qts atf trans fluid
run car for 5 to 10 min drain out and refill with a good
oil and change the filter. This may loosen stuck lifter
old school trick i quess.

If this doesnt work then they said tear down is possible