i can not figure out this stupid noise and its making me quite angry, theres a knock some where and seems like a rod knock but something i havnt seen before is when i hold rms the noise goes away but if im gaining them or loosing rpm's the knock is still there its not a loud knock but i want to get to the bottom of it before it cause more damage

any ideas how to find where its coming from or what it is if i have to replace cam im just going to upgrade every thing that goes along with it

 

If you've got a rod knocking there is no getting to the bottom of it before it causes more damage, it already needs to be rebuilt.

 

yes i know i have to rebuild it but i dont know if its a rod, the cam, lifters, rockers or on the other side of the motor rod bearings i just need a way to tell

 

Valvetrain parts don't really knock, they tick. If it's knocking, that's something deeper inside. When you start taking it apart to rebuild it, you'll know what it is.

 

it seems like rockers because thats where the sound is bad pulled valve covers of and it seems to be there but i cant tell for sure would backlash do it?

 

Lash the valves and if the sound goes away, then it'd be a valvetrain problem. The next thing you'd want to know is why the lash changed.

 

do you know lash? on 91 it 5.0 umm and whats the max lift of the vales because i throw in a cam new rocks and rods and umm there 1.5 rockers

 

lash is .000 -.020-.030. when the intake valve on the cylinder you are adjusting has just closed or is about too adjust the exhaust valve, if the exhaust valve is just starting to open adjust the intake valve. or set the motor to tdc #1 compression stroke adjust (check) both #1 rockers the exhaust valves on 3,4,and 8, and intake valves of 2,5, and 7 then turn the motor over to tdc number one exhaust stroke and check/adjust exhaust valves 2,5,6 and 7, and the intake valves of 3,4,6, and 8. to set lash take all slack out then go one full turn on the rocker nut to preload the lifter .020-.030. Sorry to tell you this bub but if the valve train in a hydrolic cam motor is making noise there's bigger problems then just a valve adjustment. Take a heater hose or tube of some kind stick one end to your ear point the other end at the car walk towards the noise that piece of hose will take you right to the noise. Once you find the problem look for other signs of problems: bent pushrods, stud pulled up, stuck valve, worn rocker arm, if your real lucky a nut backed off a rocker.

~Couch

 

thanks thats really helpfull

 

is there any way to tell if its hydro with out pulling intake?

 

If it's stock it's hydro. If you have had it any amount of time you would have known by now surely if it was a solid but on the strange chance that it is you can run the car for a few minutes shut it off and quickly pull the valve cover. If it's hydro you will see all the lifters bleeding off in that the rockers will be "ticking" back down into the blocks direction settling the valves into a more closed possition with a solid cam they will just sit there. Thats the only way I can think to tell you to give you a sure answer. i could tell you if I was there if it was one or the other, but it's experiance that tells me. that would be the least technical way to give you a deffinate answer.

~Couch