C5 Tech Corvette Tech/Performance: LS1 Corvette Technical Info, Internal Engine, External Engine, Tech Topics, Basic Tech, Maintenance, How to Remove & Replace
Sponsored by:
Sponsored by:

Tapping noise

Old Mar 6, 2011 | 03:22 PM
  #1  
PF597's Avatar
PF597
Thread Starter
8th Gear
 
Joined: Feb 2007
Posts: 8
Likes: 0
Default Tapping noise

I have a loud tapping noise on cold startup. When oil temp gets to 160 it can only be heard from outside car with hood open. I have removed all rockers and pushrods. They look good and I don't see any broken springs. I used a stethescope and the tapping is loudest at the waterpump and front cover. All belts were removed and no change. I don't think it is piston slap because it lasts too long and never stops. Thanks for any advice.
Reply
Old Mar 6, 2011 | 04:30 PM
  #2  
David426's Avatar
David426
Safety Car
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Oct 2004
Posts: 4,816
Likes: 132
From: Plano TX
Default

piston slap... very common on LS1 http://pistonslap.com/
Reply
Old Mar 6, 2011 | 05:20 PM
  #3  
sfc rick's Avatar
sfc rick
Le Mans Master
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Nov 2009
Posts: 6,119
Likes: 156
From: Huntington tx
Default

I encountered a tapping noise last month and swore it was a lifter. But I found a loose spark plug. Go figure?
Reply
Old Mar 6, 2011 | 06:20 PM
  #4  
dgrant3830's Avatar
dgrant3830
Tech Contributor
10 Year Member
 
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
Default

How many miles on the clock? I had a lifter(s) go bad on me but it wasn't till way up there in miles...270k range, replaced lifters at 274k. Mine started by tapping briefly when cold then go away quickly. The tapping time progressed as time went by till it wouldn't go away till the engine started heating up. Then all of a sudden, it became loud. Tore down the top end and replaced lifters, springs, rockers, pushrods, guides, seals and all needed gaskets of course. No more problems.
Reply
Old Mar 6, 2011 | 06:30 PM
  #5  
PF597's Avatar
PF597
Thread Starter
8th Gear
 
Joined: Feb 2007
Posts: 8
Likes: 0
Default

30,000 Miles. I do have some piston slap but it only lasts for a minute.,this is much louder and never stops.
Reply
Old Mar 6, 2011 | 06:52 PM
  #6  
dgrant3830's Avatar
dgrant3830
Tech Contributor
10 Year Member
 
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
Default

Might want to pull your codes in case of a misfire taking place but sort of sounds like a bad lifter...really bad. Might try doing a compression test to verify and expecially on the #1 or 2 cylinders since you are hearing it up front.
Reply
Old Mar 7, 2011 | 06:25 PM
  #7  
PF597's Avatar
PF597
Thread Starter
8th Gear
 
Joined: Feb 2007
Posts: 8
Likes: 0
Default

No codes. On cold startup when the noise is loudest at water pump. When I put the stethescope at a point where the head meets the block near the lifter area the sound is much quieter. When I first heard the noise I thought lifters. After using the stethescope I am not sure.
Reply
Old Mar 8, 2011 | 05:00 PM
  #8  
a/c man's Avatar
a/c man
Le Mans Master
10 Year Member
 
Joined: Jan 2009
Posts: 7,767
Likes: 19
From: East Texas
Default

Originally Posted by PF597
No codes. On cold startup when the noise is loudest at water pump. When I put the stethescope at a point where the head meets the block near the lifter area the sound is much quieter. When I first heard the noise I thought lifters. After using the stethescope I am not sure.
try running it with the drive belt off,but ony long enough to hear if it goes away could be the water pump
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-1

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-2

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-3

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
story-4

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

 Joe Kucinski
story-5

How Much Horsepower Every Corvette Engine "LOST" in 1972

 Joe Kucinski
story-6

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-7

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-8

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-9

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
Old Mar 9, 2011 | 02:05 PM
  #9  
PF597's Avatar
PF597
Thread Starter
8th Gear
 
Joined: Feb 2007
Posts: 8
Likes: 0
Default

I had all the belts off. No difference.
Reply
Old Mar 9, 2011 | 08:17 PM
  #10  
a/c man's Avatar
a/c man
Le Mans Master
10 Year Member
 
Joined: Jan 2009
Posts: 7,767
Likes: 19
From: East Texas
Default

do a compression check i had a collapsed piston do that! ran great but had low compression on that piston and tapped all the time
Reply
Old Mar 9, 2011 | 08:33 PM
  #11  
Bill Dearborn's Avatar
Bill Dearborn
Tech Contributor
25 Year Member
Liked
Top Answer: 1
Top Answer: 3
 
Joined: Oct 1999
Posts: 41,055
Likes: 9,817
From: Charlotte, NC (formerly Endicott, NY)
Default

When I first started reading your post I thought piston slap but once I finished I think it isn't. Piston slap goes away once the engine is warm. Piston slap noise usually disappears once the oil temp is in the low 100s. It will be loud for quite some time if the engine is idling and warming up but as the oil temp comes up it will all of a sudden diminish in volume until it can't be heard over the space of 40 to 50 seconds.

Bill
Reply

Get notified of new replies

To Tapping noise



Thread Tools
Search this Thread

All times are GMT -4. The time now is 07:30 PM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-9
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE