Tap Tap Taparoooo... w/vid
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On The Tree
Joined: Feb 2004
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From: Fayetteville, NC
Tap Tap Taparoooo... w/vid Well, I've developed a pretty anoying tap/tick at idle. It goes away at anything higher than idle. I've determined that it's coming from the drivers side. I removed my valve cover over the weekend, & all seems well under there. No broken springs (PRC duals) etc... It runs great, & pulls harder now than it ever has, no hesitations, misfires, etc... I tune with HPTuners, & have a datalogging addiction so I'd see it if something looked out of wack, nothing does. Anyway, I'm thinking it might be a developing lifter problem, but can't check those without removing the head. Take a quick listen below, try to ignore the valvetrain noise & you'll hear it. Mods in sig...
http://www.youtube.com/watch?v=2XqZUtN2xN0
http://www.youtube.com/watch?v=2XqZUtN2xN0
Joined: Dec 2004
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From: Dallas (Richardson), TX, USA
My car is down for the exact same issue... also on driver's side. Take a look at my thread to see some pictures of what I found. Basically, the rockers, push rods, and springs all looked fine, but a couple valves on the driver's side had the top of their stems hammered down some (pics in thread). There were no signs of P-t-V contact. I'm replacing the lifters, the bad valves, and shimming the springs (which it seems should have been done in the first place). I'll post up what I find in that thread.
So, all I can suggest, based on my experience, is that you look very closely at the tops of the valve stems as it's fairly easy to miss with a cursory look. You may have the same problem I do (whatever that may be).
So, all I can suggest, based on my experience, is that you look very closely at the tops of the valve stems as it's fairly easy to miss with a cursory look. You may have the same problem I do (whatever that may be).
Happy Gilmore 
, love that movie...
So, all the springs looked fine including the inner spring?
Did you do anything while driving before this happened?
It could very well be a lifter not pumping up, it's only at idle right? Your valvetrain seems pretty noisy, that could just be the cammera though.
Dan
, love that movie...So, all the springs looked fine including the inner spring?
Did you do anything while driving before this happened?
It could very well be a lifter not pumping up, it's only at idle right? Your valvetrain seems pretty noisy, that could just be the cammera though.
Dan
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On The Tree
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From: Fayetteville, NC
Originally Posted by DanZ28
Happy Gilmore , love that movie...
So, all the springs looked fine including the inner spring?
Did you do anything while driving before this happened?
It could very well be a lifter not pumping up, it's only at idle right? Your valvetrain seems pretty noisy, that could just be the cammera though.
Dan
, love that movie...So, all the springs looked fine including the inner spring?
Did you do anything while driving before this happened?
It could very well be a lifter not pumping up, it's only at idle right? Your valvetrain seems pretty noisy, that could just be the cammera though.
Dan
That's right, it's only at idle. Goes away when I'm driving, & runs great. The valvetrain is pretty noisy, but sounds much worse in that vid, it was taken with my still camera.
I'm going to check the spark plugs after work, as I changed them around 500 miles ago. Matbe one is backing out a bit?
I don't know but I'm doing the exact same thing post head/cam install.. I've posted trying to get an answer too. The guy that did my car said that it was tapping like that right after the install. He claims that it's the dual springs and .600 lift cam at fault. I don't know.
Valve train noise is one thing, if it's tapping, theres something not right. Mine did this after over revving it at the track but it it came and went at all RPMs. The lifter went in mine.
What about lifter pre-load, that ok?
Dan
What about lifter pre-load, that ok?
Dan
My car sounds exactly the same. I've replaced the short block, 3 different lifters, 2 sets of headers, 6 different pushrods, 3 different rocker arms. No difference. I do not believe you have a broken part. At this point, I think it is the valves slapping the aluminum heads with high profile cam lobes and dual springs being magnified with long tube stainless headers.
My guess is if I put on LS6 heads with original springs and the original LS6 cam, the noise would go away. If anyone has a combo like mine and gets it to be quiet, please PM me.
My guess is if I put on LS6 heads with original springs and the original LS6 cam, the noise would go away. If anyone has a combo like mine and gets it to be quiet, please PM me.
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On The Tree
Joined: Feb 2004
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From: Fayetteville, NC
Originally Posted by Byter
My car sounds exactly the same. I've replaced the short block, 3 different lifters, 2 sets of headers, 6 different pushrods, 3 different rocker arms. No difference. I do not believe you have a broken part. At this point, I think it is the valves slapping the aluminum heads with high profile cam lobes and dual springs being magnified with long tube stainless headers.
Well, that makes me feel a little better I guess. Maybe it's a pewter FRC thing?
Originally Posted by Byter
My car sounds exactly the same. I've replaced the short block, 3 different lifters, 2 sets of headers, 6 different pushrods, 3 different rocker arms. No difference. I do not believe you have a broken part. At this point, I think it is the valves slapping the aluminum heads with high profile cam lobes and dual springs being magnified with long tube stainless headers.
My guess is if I put on LS6 heads with original springs and the original LS6 cam, the noise would go away. If anyone has a combo like mine and gets it to be quiet, please PM me.
My guess is if I put on LS6 heads with original springs and the original LS6 cam, the noise would go away. If anyone has a combo like mine and gets it to be quiet, please PM me.
Also he said it developed, it wasn't always there.
another possibility is the valve train noise is magnifying the natural ticking the injectors tend to make.....which is normal.
if it was a bad lifter, i would think the engine would run weak, not strong.
if it was a bad lifter, i would think the engine would run weak, not strong.
May not be a lifter, but the more you rev the motor, the more oil gets passed through the lifer causing it to pump up harder till it's basically solid were you wouldn't see it run weak. At idle, there could be an issue with one not getting enough oil maybe or its defective. I'm in no way saying it's this, just don't rule it out. I'm sure you can tell the difference between valvetrain noise or ticking injectors compared to a loud taping sound that you can here quite well from even under the car.
Dan
Dan
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On The Tree
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From: Fayetteville, NC
What about my pushrod length?
My setup is: heads = 66cc, 217 intake runner, 80 exhaust runner, 2.02 intake valve, 1.57 exhaust valve; cam = LGM G5X-3 114 lsa; Pushrods = Trick Flow hardened 7.400".
Are my pushrods too short? Could this be causing the noise?
My setup is: heads = 66cc, 217 intake runner, 80 exhaust runner, 2.02 intake valve, 1.57 exhaust valve; cam = LGM G5X-3 114 lsa; Pushrods = Trick Flow hardened 7.400".
Are my pushrods too short? Could this be causing the noise?
Did you install them yourself and if so did you check lifter pre-load? Off hand, i would say if the trick flows have the same specs as a stock LS1 head (as far as deck to rocker pedestal) then 7.4's should be plenty long. best thing to do is pull off the valve cover and check your pre-load to make sure.
Dan
Dan
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On The Tree
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From: Fayetteville, NC
Originally Posted by DanZ28
Did you install them yourself and if so did you check lifter pre-load? Off hand, i would say if the trick flows have the same specs as a stock LS1 head (as far as deck to rocker pedestal) then 7.4's should be plenty long. best thing to do is pull off the valve cover and check your pre-load to make sure.
Dan
Dan
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https://ls1tech.com/forums/generation-iii-internal-engine/586025-slight-knock-18k-miles.html
thats what i hear kind of.. but not as loud.
thats what i hear kind of.. but not as loud.
Originally Posted by TSDuke
I did install them, & did not check lifter preload. I did my heads & cam swap per ls1howto.com. Torqued rockers to 23ftlbs, rotated the motor a few times, retorqued to 23ftlbs.
. There is all kinds of info around here on how to do it as well. 
i will throw in my two cents...
ever since I added LT's to the mods, it seemed to amplify the valvetrain/sewing machine tapping.
My car PULLS like a beast...so I never worry about it...
Also, I have a bit of a hiss sound when i give ita bit of gas and let off in neutral...like reeeevvvvvvvvvv HISSSSSSSSSSSSSSSSSSSSS
if you get how that sounds ha
If you car runs hard, and you checked all springs..I wouldn't be concerned...
I am NOT a mechanic BTW, so, do not live by what I say, I've just heard it a lot on MANY ls1's....
Erik
ever since I added LT's to the mods, it seemed to amplify the valvetrain/sewing machine tapping.
My car PULLS like a beast...so I never worry about it...
Also, I have a bit of a hiss sound when i give ita bit of gas and let off in neutral...like reeeevvvvvvvvvv HISSSSSSSSSSSSSSSSSSSSS
if you get how that sounds ha
If you car runs hard, and you checked all springs..I wouldn't be concerned...
I am NOT a mechanic BTW, so, do not live by what I say, I've just heard it a lot on MANY ls1's....
Erik
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On The Tree
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From: Fayetteville, NC
Originally Posted by blubird
When you rev the motor and the sound goes away does it come back immediately after releasing the throttle or does the engine have to return to idle for the noise to return?