HELP, installed heads and new cam, knocking like hell!!
When I put new lifters in, they made alot of noise for a while, sounded like loud banging as well. It took several minutes for it to go away but it finally went quite. You think this could be your issue, lifters just not pumped up yet?
Dan
Dan
Originally Posted by vettenuts
Do you have access to a boroscope? That would be helpful in examining the valves, cylinders, etc. without disassembly as a starting point.
i doubt most people on this board even know what that is
Originally Posted by DanZ28
When I put new lifters in, they made alot of noise for a while, sounded like loud banging as well. It took several minutes for it to go away but it finally went quite. You think this could be your issue, lifters just not pumped up yet?
Dan
Dan
Originally Posted by oange ss
i doubt most people on this board even know what that is
Originally Posted by 97383LT4
If you decide to start the car again youi ight want to pick up a stethscope at autoparts store to see were the knocking nosie is coming from.
It's noisey
Originally Posted by 97383LT4
If you decide to start the car again youi ight want to pick up a stethscope at autoparts store to see were the knocking nosie is coming from.
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No bent valves, pumped air into the cylinders, sealed shut, just a faint sound of air that is normal. I tapped on the valves and they made a pop, and shut like they are supposed to be.
Ed said to reset the rockers and run it longer, maybe air in the lifters or something.
Good news I must have installed the heads and cam right, so we can eliminate PTV issues Yipee! 
If it still knocks after a few mins, I will drain the oil and look for metal, if it's there, rod bearing went and at a VERY bad time!
Ed said to reset the rockers and run it longer, maybe air in the lifters or something.
Good news I must have installed the heads and cam right, so we can eliminate PTV issues
Yipee! If it still knocks after a few mins, I will drain the oil and look for metal, if it's there, rod bearing went and at a VERY bad time!
How long did the motor sit after pulling the heads? The reason I ask is that I've seen cam lobes become pitted after being soaked by coolent from the head removal when the motor sat for a long period of time. Possible the coolent galled the main/rod bearings?
Did you change the oil before the initial start up?
How long did you run the motor after the installs before you shut it down?
FWIW.... I've had motors after a H/C swap w/new lifters sit there and make all kinds of racket for several minutes even after oil pressure came up.
When you said it runs smooth and revs fast.... no irratic behavier.... I'm leaning toward it just didn't run long enough to pump up the lifters completely/bleed all the air out of the system.
Good luck-
Did you change the oil before the initial start up?
How long did you run the motor after the installs before you shut it down?
FWIW.... I've had motors after a H/C swap w/new lifters sit there and make all kinds of racket for several minutes even after oil pressure came up.
When you said it runs smooth and revs fast.... no irratic behavier.... I'm leaning toward it just didn't run long enough to pump up the lifters completely/bleed all the air out of the system.
Good luck-
Last edited by LowETz; Nov 18, 2005 at 09:41 PM.
Originally Posted by GuitsBoy
That'd be rough if he's pinging at idle!
I had it happen to me though. Some nasty knocking. Seems it was bad gas mixed with the stock tune.
Well I readjusted the rockers, set the preload with the 7.35 pushrods, started it up, let it idle for some time, and had a couple local car guy friends here, and it's not knock anymore, it's VERY excessive valvetrain noise, like a MILLION sewing machines. I left Ed a message to see what he thinks, the preload I thought was about right, but not sure if the comp 850 lifters are THAT noisey or what. I took the car for a little spin around the block, kept the rpms under 2500, and the noise gets louder with RPM, definitely valvetrain, you can hear it if you put your ear next to the valve cover. But the car runs FLAWLESSLY, no bucking, no stumbling, better than it did with my X4 and stock heads, just butter and this is without a retune yet.
So, now it's time to track down the valvetrain noise, not sure if the pushrod length is wrong or what. I will see what Ed says.
It didn't get up to full operating temps, maybe coolant temps of 130 or so, didn't want to run it too long if something is up. The pistons definitely didn't hit the valves as none where bent.
Good news so far, I just can't live with that much valvetrain noise. I will get a video of it tomorrow and post so you can hear what I got
But for now, I am much relieved that it's not a spun rod bearing. I will change the oil tomorrow and see what's in there. I didn't change it before start up as I was planning to afterwards once the crap got out of the top end.
I wonder if my lifters are bad? They are brand new but who knows...
So, now it's time to track down the valvetrain noise, not sure if the pushrod length is wrong or what. I will see what Ed says.
It didn't get up to full operating temps, maybe coolant temps of 130 or so, didn't want to run it too long if something is up. The pistons definitely didn't hit the valves as none where bent.
Good news so far, I just can't live with that much valvetrain noise. I will get a video of it tomorrow and post so you can hear what I got
But for now, I am much relieved that it's not a spun rod bearing. I will change the oil tomorrow and see what's in there. I didn't change it before start up as I was planning to afterwards once the crap got out of the top end.
I wonder if my lifters are bad? They are brand new but who knows...
You said KNOCK, but the sound you hear when you first start the engine after top end work is more like the sewing machine that needs oil sound. You even see TV commercials these days showing people making funny noises with their mouths while trying to mimic the sound their car makes when it malfunctions. We wouldn't laugh if it weren't true. KNOCK is more like one moveable object hitting another non-movable object. KNOCK is much worse than tick. If you actually had KNOCK which resulted in 8 bent intake valve stems you wouldn't continue to idle properly and rev quickly. I know it hurts to stand there and listen to your motor make all those horrible sounds when you first start it after having spend a lot of time and money to fix it up, but you have to learn to bite your lip or grit you theeth for those few minutes that seem to last an eternity until she quiets down.
I am glad the knock is gone, with that much lift it is going to sound like a large sewing machine. I would never thought that cam on those heads would clear stock pistons, but we can all be wrong sometimes. G/L
Originally Posted by dudas35
I am glad the knock is gone, with that much lift it is going to sound like a large sewing machine. I would never thought that cam on those heads would clear stock pistons, but we can all be wrong sometimes. G/L
And as for the cam, it's a lot to do with the valve events, etc. It's not an off the shelf cam, I had Ed make it to my exact mods and car, so far it's perfect! JMO.... but I ALWAYS change the oil before initial start up w/some cheap dyno oil. Too much garbage in the oil pan after a head swap. You'll be suprised how bad the oil looks when you pull the plug....I'll let it run until it reaches operating temps and make sure everything is propper, then change it again w/the good stuff..... but that's just me.
My oil was clean as a whistly 
I'd definatly check those p-rods, I don't see why you would need the 7.35's anyhow. The heads aren't milled. You should do a whipe test to find the length you need.
I'd definatly check those p-rods, I don't see why you would need the 7.35's anyhow. The heads aren't milled. You should do a whipe test to find the length you need. I plan to change the oil before I redo the pushrods today. The heads aren't milled but I'm using a thinner gasket. The heads were deck cleaned, probably not that much taken off. Just figured I would have both sets in case one wasn't right.