Notices
GM Engine & Exhaust Performance EFI | GEN I/GEN II/GEN III/GEN IV Engines |Small Block | Big Block |

Help me with valvetrain noise before i go insane...please

Thread Tools
 
Search this Thread
 
Old 10-23-2004, 04:44 AM
  #1  
TECH Enthusiast
Thread Starter
iTrader: (1)
 
Stroker 1500's Avatar
 
Join Date: Mar 2003
Location: fresno, ca
Posts: 613
Likes: 0
Received 0 Likes on 0 Posts
Default Help me with valvetrain noise before i go insane...please

This is on a 98 silverado 383 but i figured maybe someone would have some advice, the way the valve train works is still pretty similar. Ok here is what happened, the engine is brand new and i just got it running last week. Amongst start up there was a lot of valve train noise which got worse as i drove which turned out to be one of my roll rockers coming loose. I pulled the rocker off and it gouged the side of the rocker and part of the self aligning washer lookin things, the roller seemed fine however. I put it all back together and started it up and it seemd to have a knock/tick comming from the passenger side of the bay (which is the side the rocker fell of on) so i drove it for a few more days and the noise continued, I then reset the preset on all the rockers and the noise was still there. After that i decided to switch the bad rocker with a good one from the other side. After that the noise seemed a little better and it sounded like the deeper noise was comming from the drivers side and there was still a tick from the passenger side. I decided to proceed with the engine break in and hope it would go away after break in when i got on. Well i finished with break in and got on it and the noise is still there and it seems more consistant then before (before it would kind of fade in and out). Im wondering if the rocker on the one side needs to be replaced and maybe the pushrod on the other side is damaged. What do you guys think and what kind of noise would a bad roller rocker make? Would a pushrod cause a ticking noise? both noises seem to increase in speed but don't get louder with increase in engine rpm
Old 10-23-2004, 05:05 AM
  #2  
TECH Regular
 
Join Date: Sep 2004
Location: Sacramento California
Posts: 498
Likes: 0
Received 0 Likes on 0 Posts
Default

It could be a lifter too.
Old 10-23-2004, 10:41 AM
  #3  
TECH Veteran
iTrader: (8)
 
gonzo 6.2's Avatar
 
Join Date: Oct 2002
Location: oregon
Posts: 4,516
Received 15 Likes on 15 Posts
Default

Brand new? its a GM crate? which heads?
Old 10-23-2004, 11:02 AM
  #4  
TECH Fanatic
iTrader: (3)
 
Kano's Avatar
 
Join Date: Oct 2003
Location: Winston Salem NC
Posts: 1,612
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by slamed 04 silverado
It could be a lifter too.

sure could
be a pecker lifting
I mean a lifter pecking
Old 10-23-2004, 07:29 PM
  #5  
TECH Enthusiast
Thread Starter
iTrader: (1)
 
Stroker 1500's Avatar
 
Join Date: Mar 2003
Location: fresno, ca
Posts: 613
Likes: 0
Received 0 Likes on 0 Posts
Default

I bought it off of a freind. It was a used block that was fluxed and then vortec heads that where rebuilt with guides, valves, seals, new springs, screw in studs etc etc. Everything else inside the motor is brand new except the rockers (new stuff is cam, lifters, pushrods etc) Its the lt4 hotcam and then crane cam 918 springs i think with lt4 lightweight retainers. The engine had been sitting for about a year since it was built i would say but was covered in a garage and the uper end was completly dissassembled before it was ran
Old 10-23-2004, 08:49 PM
  #6  
TECH Addict
 
Keith's Avatar
 
Join Date: Oct 2002
Location: Mefis
Posts: 2,544
Likes: 0
Received 0 Likes on 0 Posts
Default

Are the heads modified to run the lift of that lt4 cam? I am pretty sure those heads(when stock) can only accomodate .450" of lift.
Old 10-23-2004, 09:01 PM
  #7  
TECH Enthusiast
Thread Starter
iTrader: (1)
 
Stroker 1500's Avatar
 
Join Date: Mar 2003
Location: fresno, ca
Posts: 613
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Fandango
Are the heads modified to run the lift of that lt4 cam? I am pretty sure those heads(when stock) can only accomodate .450" of lift.
yes they have been modified and checked to make sure the accomodate the .525 lift of the lt4 hot cam with my ratio rockers... the max lift with my heads is like .560 with my setup

the noise only sounds like it is from one lifter/rocker/pushrod/ just don't know what is causing the noise and it kinda makes it sound like a diesel and im sick of hearing the noise... it is definately valvetrain somewhere to
Old 10-23-2004, 11:00 PM
  #8  
TECH Resident
iTrader: (19)
 
chevymec's Avatar
 
Join Date: Jul 2004
Location: Richlands N.C.
Posts: 976
Received 15 Likes on 13 Posts
Default

When you broke in the motor did you prime the oil pump and made sure that oil came up to all the rocker arms? Also I'd say recheck the pushrod from the bad rocker arm came from.
Old 10-24-2004, 12:31 AM
  #9  
TECH Enthusiast
Thread Starter
iTrader: (1)
 
Stroker 1500's Avatar
 
Join Date: Mar 2003
Location: fresno, ca
Posts: 613
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by chevymec
When you broke in the motor did you prime the oil pump and made sure that oil came up to all the rocker arms? Also I'd say recheck the pushrod from the bad rocker arm came from.
before i started it i primed the oil system and held the pressure at 60psi for about 30 seconds and checked to make sure there was sufficient flow to the rockers and there was.. i pulled the push rod out and it seemed fine but i didn't examin it closely or roll it on a glass table or anything like that. Also if the aligning part of the rocker is messed up what kind of noise could that cause if any, i really don't see it as being a cause of noise on the rocker because the rocker still holds its center fine
Old 10-24-2004, 01:32 AM
  #10  
TECH Veteran
iTrader: (8)
 
gonzo 6.2's Avatar
 
Join Date: Oct 2002
Location: oregon
Posts: 4,516
Received 15 Likes on 15 Posts
Default

bolt on some stock 1.5 self align OE rockers,they should be cheap and good used one near free.Anything other than OE rockers the valve covers have to be modded for clearence,hopefully you dont have a ton of metal that went thru the motor because the rockers rubbing inside the valve covers.I am guessing you have 1.6 golds,I seem to hear storys about 1.6s from time to time, check to see if rockers are hitting the tops of the retainer or keepers,or if the self-align guides of the rockers are hitting the tops of the retainers.checked for correct push rod length?


Quick Reply: Help me with valvetrain noise before i go insane...please



All times are GMT -5. The time now is 03:25 AM.