BB Lifter Problem - Rebuild or Just Fix
Thread Starter
Safety Car
Joined: Apr 2000
Posts: 3,802
Likes: 61
From: Wichita KS
BB Lifter Problem - Rebuild or Just Fix
Problem found. See my 02/23 post.
My engine started making a clattering noise and running poorly last week. Like one of the cylinders was not firing.
Then it clears up for a while but it always comes back. After listening to it carefully, I and my friends have determined that it is likely a hydraulic lifter that is not always pumping up and therefore not always opening the valve. Sounds like it is the number 2 cylinder.
The car has at least 95K miles on it so the question is, do I just replace the lifters or do I rebuild the engine completely?
I don't know for sure how many miles are on it because the odometer stopped at 95620 before I acquired it.
If I just fix it howlikely is it that something else inside will go belly up?
If I rebuild it, I would like to up the horsepower to 1970 specs if it doesn't cost much more than rebuilding it to original 1972 specs.
I don't want to have to switch to premium gas if I can avoid it.
Any suggestions/help appreciated.
cc
My engine started making a clattering noise and running poorly last week. Like one of the cylinders was not firing.
Then it clears up for a while but it always comes back. After listening to it carefully, I and my friends have determined that it is likely a hydraulic lifter that is not always pumping up and therefore not always opening the valve. Sounds like it is the number 2 cylinder.
The car has at least 95K miles on it so the question is, do I just replace the lifters or do I rebuild the engine completely?
I don't know for sure how many miles are on it because the odometer stopped at 95620 before I acquired it.
If I just fix it howlikely is it that something else inside will go belly up?
If I rebuild it, I would like to up the horsepower to 1970 specs if it doesn't cost much more than rebuilding it to original 1972 specs.
I don't want to have to switch to premium gas if I can avoid it.
Any suggestions/help appreciated.
cc
Last edited by CCrane65; Feb 23, 2007 at 10:03 PM.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
It's likely just a collapsing lifter as you suspect. It's an easy operation to change lifters. A full new set is a safe idea in case any more are close to failing.
Maybe pull the oil pan, inspect the bearings and cylinder bores.
If you feel there are other issue besides the lifters, then perhaps a rebuild is a good idea as well.
Maybe pull the oil pan, inspect the bearings and cylinder bores.
If you feel there are other issue besides the lifters, then perhaps a rebuild is a good idea as well.
Thread Starter
Safety Car
Joined: Apr 2000
Posts: 3,802
Likes: 61
From: Wichita KS
Thread Starter
Safety Car
Joined: Apr 2000
Posts: 3,802
Likes: 61
From: Wichita KS
I'll let you know how it goes.
cc
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
I'm gonna' step out on what some may consider a limb here.
If a lifter is bad, and you put a new lifter on a used cam, you may end with a cam that's flat. A new cam and lifter(s) establishes a wear pattern. A new lifter will have a new surface- no wear patten. As it wears in, it will usually eat the surface off an old cam. And now it's a flat cam.
I'd suggest a careful inspection of the valvetrain components. Spring, rocker, pushrod, and then pull that lifter and look at it.
If a lifter is bad, and you put a new lifter on a used cam, you may end with a cam that's flat. A new cam and lifter(s) establishes a wear pattern. A new lifter will have a new surface- no wear patten. As it wears in, it will usually eat the surface off an old cam. And now it's a flat cam.
I'd suggest a careful inspection of the valvetrain components. Spring, rocker, pushrod, and then pull that lifter and look at it.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Team Owner
Joined: Aug 2004
Posts: 22,437
Likes: 2
From: Hamburger Hill...MAY 69
St. Jude Donor '08
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Great point, and it makes me wonder just how complex that wear pattern would be. I mean, don't all non-roller lifters spin during operation?
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
I've heard of guys swapping lifters and running for years. But IMHO, the odds are against it. If I rebuild an engine and use the same cam/lifters, I have a 2x4 I drilled 1" holes in and numbered to be sure I put the same lifter back in the same place.
Thread Starter
Safety Car
Joined: Apr 2000
Posts: 3,802
Likes: 61
From: Wichita KS
Well, I poured the MM Oil in this morning and ran the engine for about 15 minutes. It seems to have taken care of the lifter noise but I won't know that for sure until I can drive it.
It is runnig a bit rough however but at 15 degrees aren't we all?
One thing's for sure, nothing much else is going to happen until we get some warm weather around here.
It is runnig a bit rough however but at 15 degrees aren't we all?
One thing's for sure, nothing much else is going to happen until we get some warm weather around here.
Last edited by CCrane65; Feb 15, 2007 at 11:19 AM. Reason: sp
Thread Starter
Safety Car
Joined: Apr 2000
Posts: 3,802
Likes: 61
From: Wichita KS
Problem found. Turns out it was not a bad lifter. It was a bad rocker arm but you gotta see this thing.
It looks like it was split nearly in half. I have no idea what could cause that and not cause any other problems. The valve is fine and there is no smoke coming from the tailpipe so I assume the piston doesn't have any holes in it.
This was on an exhaust valve so there was obviously a lot of pressure building up in the cylinder because the rocker wasn't even touching the valve.
Once I replaced the rocker the car started running great. By the way, the rocker retaining nut wasn't loose or anything so it wasn't caused by that.
So, any ideas what could have caused this and why nothing else got broken?
See it here:
Yeah I know, it's pretty fuzzy.
cc
It looks like it was split nearly in half. I have no idea what could cause that and not cause any other problems. The valve is fine and there is no smoke coming from the tailpipe so I assume the piston doesn't have any holes in it.
This was on an exhaust valve so there was obviously a lot of pressure building up in the cylinder because the rocker wasn't even touching the valve.
Once I replaced the rocker the car started running great. By the way, the rocker retaining nut wasn't loose or anything so it wasn't caused by that.
So, any ideas what could have caused this and why nothing else got broken?
See it here:
Yeah I know, it's pretty fuzzy.
cc
Drifting
Joined: May 2005
Posts: 1,909
Likes: 6
From: Lake Arrowhead - Georgia > 72 Base Coupe & 74 BB Roadster
I had "something" stuck in my old GMC pickup one time. Changed the oil and substituted a quart of Marvel. (My Dad loved that stuff) I drove it about 20 miles....you could feel it immediately when the lifter unstuck. I drove that oil for about 1000 miles, than went back with plain ole Castrol. Been fine ever since....12 years ago.
Good Luck !
Nevermind......I just saw your picture of the rocker....Marvel is good stuff, but it won't fix that!
Last edited by fotyfobravo; Feb 23, 2007 at 10:02 PM. Reason: spelling
Race Director
Joined: Feb 2005
Posts: 16,100
Likes: 17
Very possible..I had that problem with a stock 73 truck 454 once..had to go to aftermarket rockers...seems residual stress was the issue with some "stamped" GM rockers from their grinding process..Edit..
I might add that once a push rod poked thru the rocker..but some broke in half like an egg...just like the pic above...GM buried their heads in the sand...
Rich
Last edited by rihwoods; Feb 24, 2007 at 12:43 AM.
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
The rocker giving up is not uncommon at all. GM has rockers that have grooved ***** to hold oil better. Move a used rocker from an intake to this exhaust spot and put the new one on an intake. Intakes run cooler per GM.
Glad you found it and it's not a big deal.
Glad you found it and it's not a big deal.
Melting Slicks
Joined: May 2001
Posts: 2,131
Likes: 4
From: May help you? You can sure as hell try!
I'd check to make sure that the oil hole in the pushrod is not clogged or that the lifter is even supplying any oil to the pushrod. I had a Cutlass years ago that had a similar issue with the rocker arm wearing severely. The oil hole in the pushrod was completely blocked shut.
Thread Starter
Safety Car
Joined: Apr 2000
Posts: 3,802
Likes: 61
From: Wichita KS
cc
