C4 Making Tapping sound
Thread Starter
6th Gear
Joined: Oct 2007
Posts: 6
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C4 Making Tapping sound
I have a 1994 LT1 Corvette. I recently had the car in the shop for a tune-up, Brakes and all fluids changed. I also replace 2 sensors.The car currently has 86,000 miles on it. When I picked the car up from the shop I notice a new sound. It has a tapping sound coming from the compartment of the engine. I'm not sure what it is
Team Owner
Joined: Feb 2006
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From: sw Ohio
The knock sensor can make a tapping noise, but it shouldnt if your using the correct octane.
If its coming from inside the engine, it could be numerous things. On top means the valves are making noise, in front could be timing chain, or god forbid its coming from the bottom thats not good. Noises from the bottom could be a spun bearing
Sorry i'm not trying to freak you out, I highly doubt with your low miles that it would anything serious.
If its coming from inside the engine, it could be numerous things. On top means the valves are making noise, in front could be timing chain, or god forbid its coming from the bottom thats not good. Noises from the bottom could be a spun bearing
Sorry i'm not trying to freak you out, I highly doubt with your low miles that it would anything serious.
Drifting
Joined: Feb 2003
Posts: 1,614
Likes: 163
From: Davis CA
Have you lifted the hood and tried to locate the sound?
I recommend that you buy a mechanics' stethescope. It looks like the doctors' device with a tube leading to a diaphragm and metal rod. Pull off the diaphragm and metal rod and you have a plastic tube that you can move about the engine bay until you locate the sound more precisely. Once you have, ask your question again.
Your concern is that the mechanics screwed up something, right? Are you certain that you are hearing a new noise or just listening more closely because you just had repairs done?
Not matter what, you will want to know the source of the noise and the tool will help. I bought mine at Sears. Check to see if they have one before you make the trip.
I recommend that you buy a mechanics' stethescope. It looks like the doctors' device with a tube leading to a diaphragm and metal rod. Pull off the diaphragm and metal rod and you have a plastic tube that you can move about the engine bay until you locate the sound more precisely. Once you have, ask your question again.
Your concern is that the mechanics screwed up something, right? Are you certain that you are hearing a new noise or just listening more closely because you just had repairs done?
Not matter what, you will want to know the source of the noise and the tool will help. I bought mine at Sears. Check to see if they have one before you make the trip.
Thread Starter
6th Gear
Joined: Oct 2007
Posts: 6
Likes: 0
The knock sensor can make a tapping noise, but it shouldnt if your using the correct octane.
If its coming from inside the engine, it could be numerous things. On top means the valves are making noise, in front could be timing chain, or god forbid its coming from the bottom thats not good. Noises from the bottom could be a spun bearing
Sorry i'm not trying to freak you out, I highly doubt with your low miles that it would anything serious.
If its coming from inside the engine, it could be numerous things. On top means the valves are making noise, in front could be timing chain, or god forbid its coming from the bottom thats not good. Noises from the bottom could be a spun bearing
Sorry i'm not trying to freak you out, I highly doubt with your low miles that it would anything serious.
Team Owner
Joined: Sep 2002
Posts: 22,209
Likes: 12
From: OBAMA IS HITLER
check your spark plugs and make sure they're all tightened sufficiently. its possible one or more wasn't tight enough when they were changed out during the tune-up.
a loose spark plug will definitely cause a tapping sound, very similar to lifters. if the sound didn't occur before taking the car in, i'll bet a loose plug is the cause.
a loose spark plug will definitely cause a tapping sound, very similar to lifters. if the sound didn't occur before taking the car in, i'll bet a loose plug is the cause.
Thread Starter
6th Gear
Joined: Oct 2007
Posts: 6
Likes: 0
check your spark plugs and make sure they're all tightened sufficiently. its possible one or more wasn't tight enough when they were changed out during the tune-up.
a loose spark plug will definitely cause a tapping sound, very similar to lifters. if the sound didn't occur before taking the car in, i'll bet a loose plug is the cause.
a loose spark plug will definitely cause a tapping sound, very similar to lifters. if the sound didn't occur before taking the car in, i'll bet a loose plug is the cause.
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Team Owner
Joined: Feb 2006
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From: sw Ohio
A loose spark plug wouldnt tap unless the piston was hitting it. It could be the lifters but more than likely its the rocker arms. You can take your valve covers off and see if you can wiggle them. They should be on there pretty tight. They will make an obnoxious tapping noise if they're not tightened down just right.
Thread Starter
6th Gear
Joined: Oct 2007
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A loose spark plug wouldnt tap unless the piston was hitting it. It could be the lifters but more than likely its the rocker arms. You can take your valve covers off and see if you can wiggle them. They should be on there pretty tight. They will make an obnoxious tapping noise if they're not tightened down just right.
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
not only could it be a lose spark plug, but I'd want to make sure they hadn't cross threaded one...which is easy to do on our aluminum heads. You really don't have to get a stethascope, a short piece of old garden hose works well also.
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
not only could it be a lose spark plug, but I'd want to make sure they hadn't cross threaded one...which is easy to do on our aluminum heads. You really don't have to get a stethascope, a short piece of old garden hose works well also.
Team Owner
Joined: Oct 2004
Posts: 81,241
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From: altered state
St. Jude Donor '05
I was thinkin what Steve posted also, but-
A loose plug can make that sound, beleive it or not. It will still fire Ok too. Best bet is a stethescope to narrow it down.
A loose plug can make that sound, beleive it or not. It will still fire Ok too. Best bet is a stethescope to narrow it down.
Drifting
Joined: Oct 2005
Posts: 1,918
Likes: 51
From: Angier nc
probably a remote possibility but it happened to me recently.i bought mine with 89k miles on it.always had a slight tick.adjusted the valves several times and no changes.it never got any louder so i left it alone until at 103k it goud louder.then really loud like it was coming apart.
we thought it was a lifter about to come apart internally(i wish).
come to find out the thrust bearing on the crankshaft was shot and when it got really loose i was hearing the counterweights touching the block.not good.rebuild time.
if yours is'nt a six speed then all of that was useless babble.
we thought it was a lifter about to come apart internally(i wish).
come to find out the thrust bearing on the crankshaft was shot and when it got really loose i was hearing the counterweights touching the block.not good.rebuild time.
if yours is'nt a six speed then all of that was useless babble.
Thread Starter
6th Gear
Joined: Oct 2007
Posts: 6
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probably a remote possibility but it happened to me recently.i bought mine with 89k miles on it.always had a slight tick.adjusted the valves several times and no changes.it never got any louder so i left it alone until at 103k it goud louder.then really loud like it was coming apart.
we thought it was a lifter about to come apart internally(i wish).
come to find out the thrust bearing on the crankshaft was shot and when it got really loose i was hearing the counterweights touching the block.not good.rebuild time.
if yours is'nt a six speed then all of that was useless babble.
we thought it was a lifter about to come apart internally(i wish).
come to find out the thrust bearing on the crankshaft was shot and when it got really loose i was hearing the counterweights touching the block.not good.rebuild time.
if yours is'nt a six speed then all of that was useless babble.
It just started happening after being in the Shop for a tune-up and brakes, fluids etc.
Le Mans Master
Joined: Aug 2004
Posts: 5,141
Likes: 7
From: Metairie Louisiana
No, but it will make a tapping sound.
I had a loose plug a few months back. It made a tapping sound similar to a lifter. There was no noticeable miss. My mpg did go down quite a bit. I tightened the plug. The sound went away and mpg went back up.
I had a loose plug a few months back. It made a tapping sound similar to a lifter. There was no noticeable miss. My mpg did go down quite a bit. I tightened the plug. The sound went away and mpg went back up.
Last edited by rickneworleansla; Oct 16, 2007 at 01:06 PM.
Team Owner
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From: OBAMA IS HITLER
Team Owner
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St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16-'17
NCM Member '09
My car did this at 120k, right after I changed oil when I got it....I ran Red-Line 10w30, as I do in all
my cars. It knocked like mad....I figured it was lifter, rocker or bad filter bypass valve....who would
have thunk I was running an oil too thin for teh motor?
Anyway, I ran some 20w50 Valvoline Racing and a quart of Lucas oil stabilizer...sound is now gone.
I stepped back to 10w40 synthetic without teh stabilizer, and teh sound is gone....
I'm not sure what it was, but the problem is gone...
my cars. It knocked like mad....I figured it was lifter, rocker or bad filter bypass valve....who would
have thunk I was running an oil too thin for teh motor?
Anyway, I ran some 20w50 Valvoline Racing and a quart of Lucas oil stabilizer...sound is now gone.
I stepped back to 10w40 synthetic without teh stabilizer, and teh sound is gone....
I'm not sure what it was, but the problem is gone...
Drifting
Joined: Oct 2005
Posts: 1,918
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From: Angier nc