Lifters bleeding down
Thread Starter
TECH Apprentice
Joined: Feb 2005
Posts: 319
Likes: 0
From: Glen Allen, VA
Lifters bleeding down Finishing up my DD rebuild of a 6.0L and the valvetrain is killing me. I have a ticking noise, but the bigger issue is the lifters are bleeding down within 10 seconds. We have measured for the correct pushrods - no change. We put various length rods in it to get preload from .030 to .080 - no change.
6.0L iron block
317 heads
mild Comp Cams cam (210/216 114/112 intake-.555; exh-.561)
new LS7 lifters
new LS6 springs
oil pressure is fine at 60#. Oil is making its way through the pushrods.
Tried the following rods. 7.400, 7.350, 7.330. Zero lash with a comp cams length checker is 7.275.
Anyone seen this before? ideas?
6.0L iron block
317 heads
mild Comp Cams cam (210/216 114/112 intake-.555; exh-.561)
new LS7 lifters
new LS6 springs
oil pressure is fine at 60#. Oil is making its way through the pushrods.
Tried the following rods. 7.400, 7.350, 7.330. Zero lash with a comp cams length checker is 7.275.
Anyone seen this before? ideas?
Thread Starter
TECH Apprentice
Joined: Feb 2005
Posts: 319
Likes: 0
From: Glen Allen, VA
thanks for the thought. We used 20/50 to break it in, plus it had some assembly lube in it. It was pretty thick. Now has 5/30 in it. No difference.
Description of what we are seeing:
manually crank motor until the springs are compressed.
within 10 seconds or so, the springs open up - pushing the lifters down. Or, the lifters are falling down allowing the springs to open.
what we are trying to figure out:
are the lifters giving out? or,
are the springs too heavy and pushing the lifters down?
Our best guess right now is that the new lifters are bad.
Would bad plastic lifter trays have anything to do with it?
Anyone else using yellow LS6 springs with LS7 lifters? I assume that combination is ok.....
Description of what we are seeing:
manually crank motor until the springs are compressed.
within 10 seconds or so, the springs open up - pushing the lifters down. Or, the lifters are falling down allowing the springs to open.
what we are trying to figure out:
are the lifters giving out? or,
are the springs too heavy and pushing the lifters down?
Our best guess right now is that the new lifters are bad.
Would bad plastic lifter trays have anything to do with it?
Anyone else using yellow LS6 springs with LS7 lifters? I assume that combination is ok.....
Thread Starter
TECH Apprentice
Joined: Feb 2005
Posts: 319
Likes: 0
From: Glen Allen, VA
Yes, 300-400 miles. It runs great. Just the sewing machine tapping noise. The only time it went away was when we did 2 WOT passes for tuning. The ticking completely went away until the motor cooled.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Thread Starter
TECH Apprentice
Joined: Feb 2005
Posts: 319
Likes: 0
From: Glen Allen, VA
Changing the oil and oil filters did not change the ticking noise (while running) or the lifters collapsing as we watched them with the motor off.
We tried 3 different pushrods from .030-.080 preload. No change with any of them as far as the lifters collapsing. We did not swap all of them out to see if the ticking would go away. Trying to solve the lifter issue first.
We tried 3 different pushrods from .030-.080 preload. No change with any of them as far as the lifters collapsing. We did not swap all of them out to see if the ticking would go away. Trying to solve the lifter issue first.
Last edited by clemsondave; Feb 13, 2009 at 10:15 PM.
I don't know... maybe an internal passage/leakage problem? The front oil passage plug (underneath the timing cover), rear plastic 'barbell' plug (installed backwards?), or maybe an issue with the front or rear cam/galley plates?
Thread Starter
TECH Apprentice
Joined: Feb 2005
Posts: 319
Likes: 0
From: Glen Allen, VA
Interesting thoughts. I replaced those with new parts. I'll ask the guy helping me to see if he specifically remembers anything special about those.
Question: if one of them falls, would that cause the pressure to go away and the others would fall? Maybe just one is bad.
Question: if one of them falls, would that cause the pressure to go away and the others would fall? Maybe just one is bad.
Yeah, not sure if it is a longshot, since you seem to have good oil pressure. I just wonder... if the front plug was missing/pushed out... but the timing cover/gasket would hold enough pressure, yet be constantly bleeding off oil, you might still get 'full' lifters at higher RPM/pump speeds... ?
...same possible scenario if that rear 'barbell' plug was backwards???
...same possible scenario if that rear 'barbell' plug was backwards???
