Tapping noise in ls2 intake (Not a lifter)!!!
Thread Starter
Joined: Mar 2007
Posts: 845
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From: Eastern Ma/ PSL florida
Tapping noise in ls2 intake (Not a lifter)!!! All right guys I am stumped on this one. Need some really experience people to chime in on this one! Little background on the car. 06 LS2 M6, BTR Stg 3 cam package, 7.4 pushrods, c5r timing chain, new oil pump, BTR dual spring kit and new valve seals, Kooks long tube headers, Kooks catted mids, magnaflow catback.
So here is whats going on. I know most ls motors make some sewing machine noises, especially with headers and a cam. My issue is I am getting a tapping noise in the top of my intake at about 2k rpm. If I put my hand on the intake I can feel it right at the front of it. At idle the motor is fine. My first thought was a bad lifter. So I just got done swapping in a brand new set of lifters and the noise is still there. The heads seemed fine, no valve marks on the pistons, no bent valves from what I can tell. No metal in the oil pan and the oil pump o-ring is not pinched. I didn't really notice the sound before the cam swap, mainly afterwards. The car has been on the dyno and driven quite a bit and the noise has not gotten any worse. The noise does seem to go right along with the valvetrain movement. I have had a spun bearing before and this definitely does not sound like a spun bearing. My only other guess is a bad intake gasket or header gasket. At the this point I am about to just drive it and say screw it all! Any professional input would be great.
So here is whats going on. I know most ls motors make some sewing machine noises, especially with headers and a cam. My issue is I am getting a tapping noise in the top of my intake at about 2k rpm. If I put my hand on the intake I can feel it right at the front of it. At idle the motor is fine. My first thought was a bad lifter. So I just got done swapping in a brand new set of lifters and the noise is still there. The heads seemed fine, no valve marks on the pistons, no bent valves from what I can tell. No metal in the oil pan and the oil pump o-ring is not pinched. I didn't really notice the sound before the cam swap, mainly afterwards. The car has been on the dyno and driven quite a bit and the noise has not gotten any worse. The noise does seem to go right along with the valvetrain movement. I have had a spun bearing before and this definitely does not sound like a spun bearing. My only other guess is a bad intake gasket or header gasket. At the this point I am about to just drive it and say screw it all! Any professional input would be great.
What intake do you have? I remember when I ported the stock intake I noticed an increase in noise. It got even worse when I put on a FAST. You just hear more of the lifter noise that's all, doesn't mean something is wrong.
It's the reason you now see intake manifolds with sound deadening material from the factory. Look at the LS3 piece, it has foam both under the intake (by the valley cover) and on top of the plenum.
It's the reason you now see intake manifolds with sound deadening material from the factory. Look at the LS3 piece, it has foam both under the intake (by the valley cover) and on top of the plenum.
Thread Starter
Joined: Mar 2007
Posts: 845
Likes: 9
From: Eastern Ma/ PSL florida
What intake do you have? I remember when I ported the stock intake I noticed an increase in noise. It got even worse when I put on a FAST. You just hear more of the lifter noise that's all, doesn't mean something is wrong.
It's the reason you now see intake manifolds with sound deadening material from the factory. Look at the LS3 piece, it has foam both under the intake (by the valley cover) and on top of the plenum.
It's the reason you now see intake manifolds with sound deadening material from the factory. Look at the LS3 piece, it has foam both under the intake (by the valley cover) and on top of the plenum.
Def not a rocker arm. I checked to see if one puked it's needle bearings and all seem good.
Can be possible valley cover bolts are keeping intake from seating down low enough to seal some intake runner in case of a Fast intake, I had to cut off half the valley cover bolts heads.
May want to remove washers from bolts if any from ls1 intake.
A sure bet with double roller timing set use with out the chain damper will cause the chain to make noise in 100% of the cases in front of the engine area.
I once send out two lifters to have checked cause I was sure they were noisy it turn out to be noisy fuel injectors, this is easy verified with a stethoscope.
Possible rocker arm heating spring retainer may require rocker clearance.
Pls let us know the outcome good luck.
May want to remove washers from bolts if any from ls1 intake.
A sure bet with double roller timing set use with out the chain damper will cause the chain to make noise in 100% of the cases in front of the engine area.
I once send out two lifters to have checked cause I was sure they were noisy it turn out to be noisy fuel injectors, this is easy verified with a stethoscope.
Possible rocker arm heating spring retainer may require rocker clearance.
Pls let us know the outcome good luck.
Thread Starter
Joined: Mar 2007
Posts: 845
Likes: 9
From: Eastern Ma/ PSL florida
Well unfortunately I only have one ls2 intake and that's the one on the car. I am not running a double roller. Just a C5R timing chain on the stock gear set. The noisy injectors sounds like a possibility.
I also just remember that most of the brass inserts for the intake bolts were missing when I pull the intake bolts out of the manifold. Any chance that could be it?
I also just remember that most of the brass inserts for the intake bolts were missing when I pull the intake bolts out of the manifold. Any chance that could be it?
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Verdad Gallardo Well unfortunately I only have one ls2 intake and that's the one on the car. I am not running a double roller. Just a C5R timing chain on the stock gear set. The noisy injectors sounds like a possibility.
I also just remember that most of the brass inserts for the intake bolts were missing when I pull the intake bolts out of the manifold. Any chance that could be it?
I also just remember that most of the brass inserts for the intake bolts were missing when I pull the intake bolts out of the manifold. Any chance that could be it?
Check the rockers clearance at point when valve is full open, split a straw open it and if it fits between rocker and spring retainer you are good, if real close check all of them.
A straw is about 0.004 thick but that's all you need.
Thread Starter
Joined: Mar 2007
Posts: 845
Likes: 9
From: Eastern Ma/ PSL florida
It may have split area around a bolt without the insert cause a possible leak, just a possibility wont hurt to replace the missing inserts, some one on here may have them.
Check the rockers clearance at point when valve is full open, split a straw open it and if it fits between rocker and spring retainer you are good, if real close check all of them.
A straw is about 0.004 thick but that's all you need.
Check the rockers clearance at point when valve is full open, split a straw open it and if it fits between rocker and spring retainer you are good, if real close check all of them.
A straw is about 0.004 thick but that's all you need.
I thought the stock length was 7.4?? Id be double checking that. Also you said you changed the lifters? Did you inspect the rollers for pitting or any unual scarring? If by chance you had a lifter go bad...it usually takes a lobe with it. Just my $.02
Thread Starter
Joined: Mar 2007
Posts: 845
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From: Eastern Ma/ PSL florida
Stock length is 7.4. But most aftermarket cams are .050 smaller base circle. I inspected all the lifters and the all were fine as far as roller damage. Had a rolled and lobe go out before on another car and it was noisy at idle. This sounds fine at idle. Really thinking its a pushrod length issue.
Stock length is 7.4. But most aftermarket cams are .050 smaller base circle. I inspected all the lifters and the all were fine as far as roller damage. Had a rolled and lobe go out before on another car and it was noisy at idle. This sounds fine at idle. Really thinking its a pushrod length issue.
Just a thought, I have a noise coming from mine that you would swear is coming from the intake area but when you get under the car is sounds like its coming from there. We have honed in on it coming from the transmission but sounds like the intake from the top. Have you used a stethoscope to help pin point?
Thread Starter
Joined: Mar 2007
Posts: 845
Likes: 9
From: Eastern Ma/ PSL florida
Just a thought, I have a noise coming from mine that you would swear is coming from the intake area but when you get under the car is sounds like its coming from there. We have honed in on it coming from the transmission but sounds like the intake from the top. Have you used a stethoscope to help pin point?
I had a loud tapping noise that I couldn't figure out in my 408 when I put it together. It was hard to pin point with a stethescope even. It turns out I was actually running too much preload for the Morel lifters. I got some shorter pushrods and the noise quieted down to typical LS valvetrain noise. I would double check how much lifter preload you are running and see if it is within the recommended range for the lifters you have.
Thread Starter
Joined: Mar 2007
Posts: 845
Likes: 9
From: Eastern Ma/ PSL florida
I had a loud tapping noise that I couldn't figure out in my 408 when I put it together. It was hard to pin point with a stethescope even. It turns out I was actually running too much preload for the Morel lifters. I got some shorter pushrods and the noise quieted down to typical LS valvetrain noise. I would double check how much lifter preload you are running and see if it is within the recommended range for the lifters you have.
Thread Starter
Joined: Mar 2007
Posts: 845
Likes: 9
From: Eastern Ma/ PSL florida
So just a little update. I have tried a set of 7.450 and those were too long. Installed a set of 7.425 and no real change.
Also used a stethoscope and pinpointed it to right on top of the front of my ls2 manifold near the MAP sensor area. Thinking its just airflow I am hearing. At a loss here!!!! Car runs fine too.
Also used a stethoscope and pinpointed it to right on top of the front of my ls2 manifold near the MAP sensor area. Thinking its just airflow I am hearing. At a loss here!!!! Car runs fine too.
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solved?! So just a little update. I have tried a set of 7.450 and those were too long. Installed a set of 7.425 and no real change.
Also used a stethoscope and pinpointed it to right on top of the front of my ls2 manifold near the MAP sensor area. Thinking its just airflow I am hearing. At a loss here!!!! Car runs fine too.
Also used a stethoscope and pinpointed it to right on top of the front of my ls2 manifold near the MAP sensor area. Thinking its just airflow I am hearing. At a loss here!!!! Car runs fine too.