Loud knocking sound after head install
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From: Coffeyville, Ks
Loud knocking sound after head install I already had a torquer 2 cam and 918 springs and i just put on stage 2.5 5.3 heads. When i was putting the heads on i took out the lifters and they all looked good. I got them seated in good and when i got everything done i fired it up and theres a knocking sound on the passenger side. almost sounds like a rocker hitting the valve cover. I took the valve covers back off and checked everything and it all looked good. torqued good and no blemishes of something hitting. I tried it again and felt around on the valve cover to see if i could feel a rocker hitting on the cover but i got nothing. Does it sound like a lifter is possibly sticking because they were fine when i put them in and i cant see a good lifter falling apart instantly on the first start up. Should i try some cleaner like rislone through it or what does it sound like and what should i do. I really dont want to have to take the intake and head back off. 
Could be a lifter, I have seen weirder stuff happen. There aren't too many modded f-bodies in that area, which one is yours?? I was just out in b-ville doin my H/C swap a few weeks ago. My buddy is the badass Silver 02' T/A runnin around there. He is down right now due to head issues but should be back out soon. If you see him he will probably be on slicks.
Have you tried turning it over with a breaker bar to make sure everything is smooth before you start it up?? Or does the noise only happen when it's actually firing??
Have you tried turning it over with a breaker bar to make sure everything is smooth before you start it up?? Or does the noise only happen when it's actually firing??
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12 Second Club
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Joined: Mar 2007
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From: Coffeyville, Ks
I've checked everything twice. Checked the pre-load and everything is right on. Took the car out last night and drove around a little bit and it ran strong. A little hesitaion here and there but it's not tuned so thats to be expected. Im missing a header bolt from getting broke in the previous head and my buddy swears it's an exhaust leak right there. Which i know there is one but its just really loud. I dunno though. Have new bolts on the way. Hopefully he's right. I'll feel kinda stupid but releived at the same time.
This is a long shot but if you can't pinpoint the sound and it may be coming from deeper w/in the engine bay, check your K-member to see if maybe your LTs aren't bumpin' up next to it.... just brainstorming.
well nothing like that has happened to my vette but I recently did a exhaust manifold gasket change on my suburban but before I did it sounded like a valve was hitting the piston but it was actually sort of a backfire noise that was happening due to the leak hopefull thats it good luck
Exhaust leaks can do really weird things and make weird noises. I would get that fixed now, fix the things that you know are wrong first. I would also do the screwdriver/broomhandle trick. Get a long screwdriver or a broom handle and put one end on your ear and the other end at various places on the motor, you'd be amazed at the things that you hear. This will help you pinpoint where the noise is coming from.
I have the same sound!! after changing 2 sets of lifters and different cam this weekend I still have it.. i finally found the sound.. it sounded like it was coming from #7 cyl which had me worried.. turns out i have a warped set of crapsetter longtubes.. i am ording a good set of american racing LT's to replace these. if you have crapsetters check that out before you do all the work i just did.
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From: Texas
hope that fixes it ... just last week i was chasing a noise in a friend of mines car after a intake swap... turned out that his fuel rail was bowed and put alot of pressure on the injector for number 8 cylinder and it cracked the plastic ring on the injector causing a really loud knocking noise when the injector fired....
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it could be your exhaust if you have a leak it will sound just like a bad lifter sometimes also if you put one of the lifter in backward it will not fill up with oil there is a small pin hole on them that has to face the oil port there is a hole on the opiste side that doesn't go all the way thew and if you put that side to the oil port it wont pump up
