Generation III Internal Engine 1997-2006 LS1 | LS6
Sponsored by:
Sponsored by:

Tapping and rough Idle

Thread Tools
 
Search this Thread
 
Old Nov 27, 2010 | 01:31 PM
  #1  
ChuckD's Avatar
Thread Starter
Teching In
 
Joined: Apr 2007
Posts: 46
Likes: 0
From: Sugar Land, Tx
Default Tapping and rough Idle

I had a slight tapping sound and a rough idle. I figured I had a bad lifter. I took the top of the motor apart getting to the lifters and when I got to the push rods I pulled all the push rods out, 1 was bent and another was bent and broke.

Any idels of what would cause this?

Thanks Guys!!!
Reply
Old Nov 27, 2010 | 02:28 PM
  #2  
Darkman's Avatar
TECH Addict
iTrader: (2)
 
Joined: Apr 2009
Posts: 2,167
Likes: 6
From: Spring, Texas
Default

If the pushrods are OEM any over-rev event (late upshift or premature downshift) can cause bent pushrods. It is not a bad idea to replace OEM with hardened pushrods even if you not doing any other modiciations.
Reply
Old Nov 27, 2010 | 02:38 PM
  #3  
nimrod.sixty9's Avatar
TECH Regular
iTrader: (5)
 
Joined: Feb 2008
Posts: 473
Likes: 1
From: Okeechobee, FL
Default

Originally Posted by Darkman
If the pushrods are OEM any over-rev event (late upshift or premature downshift) can cause bent pushrods. It is not a bad idea to replace OEM with hardened pushrods even if you not doing any other modiciations.
Sorry to threadjack,
But would bent pushrods cause a sewing machine type sound on the bottom end? I cant really tell it may be my exhaust as I only stuck my head under there for just a minute or so.
I may have to do my valve seals soon and was just wondering if I should go ahead and do this. Not to mention my car is a stick and has high mileage.
Links to a good product?
Reply
Old Nov 27, 2010 | 03:46 PM
  #4  
Darkman's Avatar
TECH Addict
iTrader: (2)
 
Joined: Apr 2009
Posts: 2,167
Likes: 6
From: Spring, Texas
Default

Noise from bent pushrods would be from the upper part of the engine, but the associated conditions could cause other sounds. A number sponsors here sell good push rods, e.g. Texas Speed, Thunder Racing, etc.
Reply
Old Nov 28, 2010 | 03:02 PM
  #5  
ChuckD's Avatar
Thread Starter
Teching In
 
Joined: Apr 2007
Posts: 46
Likes: 0
From: Sugar Land, Tx
Default

Thx for the info. It has 215,000 miles so dont quess new pushrods could hurt.
Reply
Old Nov 29, 2010 | 10:28 PM
  #6  
Whiteaw57's Avatar
TECH Resident
iTrader: (2)
 
Joined: Sep 2010
Posts: 909
Likes: 0
From: Salisbury, NC
Default

I think nimrod meant noisy in the lower rpms, the answer is yes to a degree. Slightly bent pushrods means that there is going to be a little more lash at the rocker arms which is where you get the tick. The reason you hear it at lower rpm however is probably just because the exhaust isnt as loud there and also with the engine at slower speed theres more time between ticks which makes them more defined. when in doubt grab some though. I think tsp has them for 109$
Reply
Old Nov 29, 2010 | 10:35 PM
  #7  
garygnu's Avatar
TECH Senior Member
 
Joined: Feb 2009
Posts: 5,445
Likes: 4
Default

remove your push rods out.roll your push rods on a flat surface,kitchen table or counter top.if you push rods are straight your lifters mite be bad at that high of mileage.look for broken valve springs or bad rocker arm trunnion bearing.ls1howto.com for instructions on removal of said pieces.
Reply




All times are GMT -5. The time now is 03:08 AM.