Rod Knock? Bad Lifter? - LS1LT1 Forum : LT1, LS1, Camaro, Firebird, Trans Am, Engine Tech Forums

Welcome to LS1LT1.com/LS3forums.com - please click here to register...

Reply
 
LinkBack Thread Tools
post #1 of 22 (permalink) Old 09-17-2011, 09:10 PM Thread Starter
Regular Member
 
Join Date: Jul 2008
Posts: 124
 
Rod Knock? Bad Lifter?

I can't seem to tell the difference between the two.

Sounds like someone is taking a screw driver and tapping my canton oil pan, but it's not from the oil pan. Noise is more toward the top then bottom, and closer to the trans then the water pump.

Here is the background. 350 Lt1 motor, rebuilt with all new bearings, stock pistons rods and lifters. Everything else is different. During all of my test startups with open headers my oil psi was 60 or more.

heres the layout from cam out: cc306 to oem lifters to hardened trickflow pushrods to 1.6 RR. 918 beehives to ferrera valves.

I've been around knocking cars... its more of a clunking noise to me.
I have not been around a lifter sound tho.

Pulled the upper valvetrain, inspected everything under the valve covers all seems ok.

Pulled the intake and removed the lifters. Lifters dont show signs of physical damage to the surface, including the rollers. ONE (from cyl 4 driver side) Lifter had a little problem. The roller wasn't rolling... still no damage to the lifter, but could this be the noise problem...

I'm just trying to put my mind at ease... I would hate to dump more cash into it for another rebuild...

Driving a bird... a bird with no wings...still wrenchin'
joonejune is offline  
Sponsored Links
Advertisement
 
post #2 of 22 (permalink) Old 09-17-2011, 09:34 PM Thread Starter
Regular Member
 
Join Date: Jul 2008
Posts: 124
 
O. I had my valve covers off for one night... the same night it rained... got a little milkshake. Drained the old oil and replaced.

also when I pulled the pan I did not see any metal chunks/particals...

I'm really hoping it was that lifter...

Driving a bird... a bird with no wings...still wrenchin'
joonejune is offline  
post #3 of 22 (permalink) Old 09-17-2011, 11:37 PM
95Z
Admin
 
Join Date: Mar 2008
Location: MD
Posts: 8,047
 
A4 or M6? Almost sounds like a bent/cracked flexplate that you are describing.

A lifter can sound like knock as can a bad exhaust leak in the right spot.

60 pounds of oil pressure is a lot, but when the oil is cold its thick enough that it won't tell the true story unless its fully warmed up ~200*F.



Yep its slow.

Making the world a warmer place one gallon at a time.
95Z is offline  
post #4 of 22 (permalink) Old 09-17-2011, 11:51 PM Thread Starter
Regular Member
 
Join Date: Jul 2008
Posts: 124
 
A4, flexplate is good spins on the starter without any movement front to back.

Just looked at the #7 exhaust lifter again... the roller doesn't roll at all.

I have a new set of lifters soaking as we speak.

I'm going to assume a bad rocker ajustment mixed with an oil/water oil (from that rainy day) destroyed this lifter... Car wasn't idling, it would start then die as if the rockers were too tight.

Driving a bird... a bird with no wings...still wrenchin'
joonejune is offline  
post #5 of 22 (permalink) Old 09-18-2011, 07:52 PM Thread Starter
Regular Member
 
Join Date: Jul 2008
Posts: 124
 
welp, got a new set of lifters and installed them today. Great news... well... here you listen...


(still knocking lol) Barf.

Driving a bird... a bird with no wings...still wrenchin'
joonejune is offline  
post #6 of 22 (permalink) Old 09-18-2011, 10:05 PM
95Z
Admin
 
Join Date: Mar 2008
Location: MD
Posts: 8,047
 
If you aren't getting any metal in the oil then I'd still go for the flexplate. You can't see it well enough when its bolted to the trans and if its cracked around the bolts or even bent from installing the trans it will knock.



Yep its slow.

Making the world a warmer place one gallon at a time.
95Z is offline  
post #7 of 22 (permalink) Old 09-19-2011, 12:52 AM
Regular Member
 
lt1beaster's Avatar
 
Join Date: Sep 2010
Location: cut bank, mt
Posts: 493
 
that sounds like rod knock to me

95 Camaro Z28 257k on body motor replaced: Manual fan switches; TB Bypass............motor go boom


[B]95 camaro z28
04 hummer h2
94 buick roadmaster 5.7l Lt1
76 twin turbo 355 c10
Shbox.com
lt1beaster is offline  
post #8 of 22 (permalink) Old 09-19-2011, 06:57 AM
Regular Member
 
lLarry N's Avatar
 
Join Date: May 2008
Posts: 265
 
seems like if its on start up and not even out on the street unless there was a huge mistake replacing bearings,I would lean more to the cracked or loose flexplate.
lLarry N is offline  
post #9 of 22 (permalink) Old 09-19-2011, 07:36 PM Thread Starter
Regular Member
 
Join Date: Jul 2008
Posts: 124
 
Car hasn't been put into drive yet... Thats how new. Rotating assemb was done by a professional builder. Car sat a while but I primed the oil prior to starting it. Couldn't hear the knock at first but I just got the exhaust on and wammo knock was clear as day.

Flex plate was installed a month ago, before install it looked fine. I will re inspect it.

The more and more I watch the vid it seems that I have accepted that it's a rod.

No loss of power from the sound of it, and it's not that loud... Yet. Maybe thicker oil will quiet it down... If it does I know it's the bearing. Anyone know the weight of oil I should run to quiet a knock? It's got 10-30 conventional now...

Driving a bird... a bird with no wings...still wrenchin'
joonejune is offline  
post #10 of 22 (permalink) Old 09-19-2011, 09:17 PM
Regular Member
 
lLarry N's Avatar
 
Join Date: May 2008
Posts: 265
 
I listened to the video over and over, to me it sounds louder on the drivers rear valve cover. Have you tried starting the car with the driver side valve cover off of it. Are all the rockers oiling? It kinda sounds like more than one lifter. At this point whats to lose? Also you could ground out the spark one cyl. at a time which should quieten down a rod knock if it comes to that.
Good luck, maybe someone else will chime in.
lLarry N is offline  
post #11 of 22 (permalink) Old 09-19-2011, 09:29 PM Thread Starter
Regular Member
 
Join Date: Jul 2008
Posts: 124
 
I just replaced all the lifters... 16 total exhaust lifter on 7cyl was all jammed up. Roller didn't roll. (driverside last lifter)

readjusted my rockers after installing the new lifters and still had the noise.

Driving a bird... a bird with no wings...still wrenchin'
joonejune is offline  
post #12 of 22 (permalink) Old 09-19-2011, 09:55 PM
Yo!
 
R3DLT1's Avatar
 
Join Date: Aug 2008
Location: Oklahoma Bartlesville
Posts: 8,172
 
Sounds like a flexplate. I had a similar sound. Ill look for the videp n post so u can compare.

Do u have stock flexplate?

Ur gonna have to remove the bolts off the TC to really examine ur flexplate. Look around where it bolts to the engine. It usually cracks around there. Use a flash light to really looks

R3DLT1 is offline  
post #13 of 22 (permalink) Old 09-19-2011, 10:00 PM
Yo!
 
R3DLT1's Avatar
 
Join Date: Aug 2008
Location: Oklahoma Bartlesville
Posts: 8,172
 
R3DLT1 is offline  
post #14 of 22 (permalink) Old 09-20-2011, 07:27 PM
Regular Member
 
jethrobodean's Avatar
 
Join Date: May 2010
Posts: 178
 
sounds like a rocker hitting the valve cover.....

1996 M6, 383, CC502, 10:1comp, 30#injectors, 1.6RR, Comp R's, CAI, TB bypass, SLP shorties and 3" full exhaust,LT4KS,
jethrobodean is offline  
post #15 of 22 (permalink) Old 09-21-2011, 01:21 AM Thread Starter
Regular Member
 
Join Date: Jul 2008
Posts: 124
 
I plan to fiddle with the car tomorrow.

yes it is a stock flex plate, as for the rockers they are 1.6rr under canton valve covers. With the covers off the noise is still present.

I am starting to think piston slap maybe... its not a deep knock like a rod, least i don't think so. (trying to compair it to a rod knock i had on my pooper buick v6 years ago)

all new rings on the piston, and again the work on the block was done by a machine shop so I would assume that he didn't bore one cyl too much. Do the rings need time to seat?

Driving a bird... a bird with no wings...still wrenchin'
joonejune is offline  
Sponsored Links
Advertisement
 
Reply

Bookmarks

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the LS1LT1 Forum : LT1, LS1, Camaro, Firebird, Trans Am, Engine Tech Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome