Bmeade05

this noise is driving me crazy it sounds like it’s coming right out of the exhaust pipe more towards the y pipe i was curious if anyone else has ran into this it doesn’t have cats and has recently been cammed any input helps thanks

youcar

exhaust issues can be tricky. hope you find a solution soon!

HappySalesman

iTrader: (3)

I would inspect the exhaust for any loose bolts or places it may be making contact with something. Do you only hear it out of the exhaust tip or can it be heard elsewhere?

Metalchipper

Just taking some shots in the dark....
What type of exhaust manifolds do you have?
With a stethascope see if you trace the noise up to the heads. Check both intake and exhaust sides of the heads and the manifolds. A long screw drive with the handle on your ear works too.
It sounds like valve train noise to me.
Hope that helps

Bmeade05

i was told it is exhuast pinging it really doesn’t affect anything i just put new manifold gaskets on it what’s wierd is it has no ticks from the engine bay i can only hear it down from the exhaust pipe closer to the y pipe i just don’t understand how it could be valve train or which part of the valve train i’ve never heard lifters make that sound but it could be i did re use all the valve train parts when i cammed it
when i put a stethoscope up to the valve cover bolts it would have the sewing machine noise but this noise seems too out of rythm to be with that it

Metalchipper

Before I put Morral lifters in my 5.3.....and replaced the loose valve guides.
I would here a higher pitch noise from what you have. But I could only hear it from the front wheel wells or if I was under the truck by the Y pipe. So I would agree that it could be "exhuast pinging" but I would call it more of tuned sound effect from something up stream that hits the pipes just right to produce the noise downstream.
Sounds kind of dumb, I know.
Next time you have the valve covers off, check the valve guides for looseness.
Hope that helps!

Bmeade05

are you referring to the rockers or the valve seals i had some side to side play in my rockers but no up and down play so i didn’t stress it but i never tourqued them down i was in a rush so i picked up a torque wrench this eveneing and am going to go over all the bolts for the rockers and check all the pushrods if all looks good i’ll just let it ride may look into putting some resonators where the cats where

Metalchipper

Nope, the valve guides, the seals will dampen the valve stem movement some what. Use a screwdriver to push on the spring retainer sideways and see if the tip of the valve wiggles. Then it is a judgement call if there is too much. If they are loose, join the club, we are and are been many. Should not hurt much if they are alittle lose, maybe use some oil and be alittle noisy.

I wish some expert valve guide experienced people would chime in, I am still looking for answers.

the_merv

iTrader: (88)

I couldn't hear it in the vid unless it's that metal screetch at the end of it vid?

My C5Z06 has this spring loaded bracket that holds the X-pipe up and it squeaks if I hit a bump just right, but that's because metal on metal on the bracket. Maybe it's flashing rubbing the exhaust on yours.

Bmeade05

i will get a video of this tomorrow when i take the valve coveres off

Bmeade05

pulled the valve cover off and this noise is basically what i was hearing when i used a stethoscope i’m not sure if it’s normal but i really ain’t stressing it it sounds like regular valve train to me doesn’t match the rythym of the exhaust note i’m hearing so idk man

Metalchipper

Thanks for the updated video.
That is not the sound that I was talking about--that you could only heard down stream in the exhaust.
Someting is wrong with your valve train in my opinion. Did you check the push rod length with the new cam install?
What valve springs and cam specs?
Let us know how the guide wear test comes out.
You should be able to pin point was cylinder-valve is making the noise that distinct and go from there.
Hang in there!

Bmeade05

i re torqued the rockers after that video and the noise went away it got a lot quieter i didn’t check pushrods wouldn’t even begin to know how to do that i’m very new to engine performance definitely will look into this

Metalchipper

That is good news. Sounds like you had a loose rocker.
If your new cam has the same size base as stock your length should be ok. If you have higher lift now you might need a better springs. Then you will need stronger push rods.
Do a search for a threads on checking push rod length to understand how. Allso a method how to rotate the cam to set each valve when it is closed. Which would of prevented your loose rocker.

grinder11

iTrader: (1)

IDK if this helps anyone out, but here goes. I have a method that works well for me. When I'm tightening the trunnion bolt, I place my index finger on one end of the axle, and my thumb on the other end. Then I eyeball the tip, placing it on the center of the valve stem. As I begin tightening the mounting bolt, I wiggle the axle slightly to help it "nest" in the mount. Never had one come loose.....YET!!!! LOL

Bmeade05

the cam is lsxelerations stage 2 212/218 .522 .529 my trucks got 243 heads and was told the springs can handle up to .550 but the pushrods i didn’t think anyone changed them with a low lift truck can it says it’s nsr on thier website

Bmeade05

i will say it has made that noise before i cammed it i think the cam has made the exhuast note change i did notice i’ve got a broken bolt on the passenger rear manifold i wonder if an exhaust leak sounds like this that’s what i’m down too i had no play hardly in the valve guides from the best of my ability to tell so i’m convinced it’s an exhaust leak at this point

Metalchipper

Should be good to go!