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

pushrod question

Thread Tools
 
Search this Thread
 
Old Jul 12, 2012 | 10:06 PM
  #1  
I Confederate I's Avatar
Thread Starter
Staging Lane
 
Joined: Jun 2012
Posts: 88
Likes: 0
From: Raleigh, NC
Default pushrod question

Alright I know I'm going on a crazy amount of posts about the same problem, but it seems to be baffling a lot of local mechanics. Everyone seems to have their own opinion of course, but no one can seem to agree.

Ok so far I've posted wondering why my 01 SS is making a valve tapping noise around 65 mph. It goes away when the car returns to idle. General consensus leads to a lifter problem. I still haven't torn into the motor to find out the state of my lifters, but I have stopped driving it. I just can't find the time right now to pull the heads. But here are a few things I have found out:
1. My #7 exhaust pushrod is *slightly* bent. So slightly you can barely see it. I dipped it in tranny fluid and rolled it on a blank piece of paper on a level surface and found gaps in the pattern it left.
2. My pushrod length is a good bit over the stock length (7.450) and that is .050 longer than TSP recommends for my cam.
3. The guy I bought the car from told me that he installed adjustable roller rockers, which was a load of crap. They are completely stock.
4. The guy at TSP (who was extremely nice) said that if my tapping is intermittent like it is, there most likely is not any damage to the cam.
5. I did find the time to go ahead and replace the spark plugs (it really needed it) and I noticed that my 2 4 6 and 8 spark plugs were really carbon fouled.

So, with this, does anyone have any suggestions that might point towards another reason I have this ridiculous tapping? Could it be caused by too much preload from the pushrods? I feel like the pushrods might be stopping a lifter from getting pumped up all the way, leading to my tapping. Once the car returns to idle, the lifter is getting the chance to get pumped up, and it stops. However, if my theory is correct, shouldn't all the lifters be tapping at some point? Or am I f*cked and I need to start ripping it apart?

Thanks so much guys, you are the best.
Reply
Old Jul 13, 2012 | 06:57 AM
  #2  
crainholio's Avatar
TECH Addict
iTrader: (2)
 
Joined: Aug 2003
Posts: 2,977
Likes: 3
Default

Right, let's measure your pushrod length for you over the Intarwebz...
Reply
Old Jul 13, 2012 | 07:21 AM
  #3  
vettenuts's Avatar
TECH Senior Member
iTrader: (4)
 
Joined: Jul 2004
Posts: 8,092
Likes: 13
From: Little Rhody
Default

Any codes or other indications on why one bank appears rich?

What mods does the car have? Sounds like at least a cam.

Is this tapping recent or has it been doing this all along?

A single pushrod is cheap, buy one and replace the one you believe to be bent and work from there. You need to evaluate problems one at a time or it will become very confusing.
Reply
Old Jul 13, 2012 | 07:24 AM
  #4  
JUSTINSWS6's Avatar
TECH Fanatic
 
Joined: Jan 2012
Posts: 1,076
Likes: 0
Default

Did you replace the bent pushrod yet? It is not your cam or it would do it all the time. I would upgrade your stock rockers to the retro fit ones comp makes. And it only makes the noise at 65 or is it the rpm you are at at 65? What rpm are you at ehen cruising 65?
Reply
Old Jul 13, 2012 | 10:32 AM
  #5  
I Confederate I's Avatar
Thread Starter
Staging Lane
 
Joined: Jun 2012
Posts: 88
Likes: 0
From: Raleigh, NC
Default

Originally Posted by JUSTINSWS6
Did you replace the bent pushrod yet? It is not your cam or it would do it all the time. I would upgrade your stock rockers to the retro fit ones comp makes. And it only makes the noise at 65 or is it the rpm you are at at 65? What rpm are you at ehen cruising 65?
It appears to happen at the rpm, not the speed. At 65 im running about 1600rpms. I can always recreate the sound at that speed, and its more difficult to do it at a different speed.

Originally Posted by vettenuts
Any codes or other indications on why one bank appears rich?

What mods does the car have? Sounds like at least a cam.

Is this tapping recent or has it been doing this all along?

A single pushrod is cheap, buy one and replace the one you believe to be bent and work from there. You need to evaluate problems one at a time or it will become very confusing.
I haven't replaced the PR yet, but like I said, im not driving it. Just as a test I moved the bent one to a different cylinder to see if the noise moved with it, but so far I can't tell.
As far as mods, I've got a cam as well as a few minor ones, such as the SLP intake box, LT headers, MSD wires, and a exhaust setup. Im not throwing any codes, but my best guess as to why I'm running rich is my illuminated o2 sensors messing with my tune. Either that or a bad connection leading to that banks coil packs. It was brought up to me that my 2 problems could possibly be related.
Reply
Old Jul 13, 2012 | 10:59 AM
  #6  
JUSTINSWS6's Avatar
TECH Fanatic
 
Joined: Jan 2012
Posts: 1,076
Likes: 0
Default

Try to turn on the car and make a video of you holding it at 1600 rpm so we can hear the noise much easier to say what it is that way.
Reply
Old Jul 13, 2012 | 07:01 PM
  #7  
crainholio's Avatar
TECH Addict
iTrader: (2)
 
Joined: Aug 2003
Posts: 2,977
Likes: 3
Default

Thinking about this a bit more, the bent pushrod is not stock length and therefore likely an aftermarket hardened piece. If something happened to bend it, there is a root cause of the problem that needs to be identified and fixed.

Next step is a $20 Comp pushrod tool to get an accurate length measurement and see how far off the current pushrods might be.

If they're long enough that the lifters are going solid and causing piston-valve contact, you'll want to get the right ones...and do a compression test on the cylinder w/ the bent one to see if the valve got bent as well.
Reply
Old Jul 13, 2012 | 10:43 PM
  #8  
I Confederate I's Avatar
Thread Starter
Staging Lane
 
Joined: Jun 2012
Posts: 88
Likes: 0
From: Raleigh, NC
Default

Decided to take the car to RPM motorsports today and have them run a compression test. All 8 are running at 175psi, so no damage has been done. She did decide to cooperate on start up after the test however, and she started tapping. After a few tests, the guys at RPM came to the conclusion that I have a "lazy lifter" that isn't staying pumped up. So, lifter job it is. Thanks for the help guys, I really appreciate it. You helped point me in the right direction.
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-1

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-2

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-3

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-4

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-5

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-6

10 Camaros You Should Never Buy

 
story-7

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
story-8

Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0

 Brett Foote
story-9

10 Reasons the LS7 Is GM's Most Extreme Naturally Aspirated V8 Engine Ever

 Verdad Gallardo
Old Jul 14, 2012 | 01:38 AM
  #9  
mark21742's Avatar
TECH Addict
 
Joined: Sep 2009
Posts: 2,481
Likes: 5
From: PA/MD
Default

Check this and report back... Lightly tighten your rockers to "0" lash, then count the turns from "0" lash to torque. Most setups "like" about 3/4-1 1/4 turns from 0 to torque...personally I found my setup works best at just a hair over 1/4 turn to torque but I don't have your "average" setup.

If your more than 1 1/4 turns to torque you need shorter pushrods and if you let us know how many turns you have we can pretty much tell you exactly what length you need since we have your pushrod length now...no need to go buy an adjustable pushrod checker.
Reply




All times are GMT -5. The time now is 11:56 AM.

story-0
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-1
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-2
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-3
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-4
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-5
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-6
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-7
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE
story-8
Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0

The world was a better place when it was still around.

By Brett Foote | 2026-01-23 09:20:37


VIEW MORE
story-9
10 Reasons the LS7 Is GM's Most Extreme Naturally Aspirated V8 Engine Ever

Slideshow: The 7.0-liter LS7 was designed for absolute cutting-edge performance.

By Verdad Gallardo | 2026-01-07 18:36:00


VIEW MORE