Whenever I gun the motor a bit, I get what sounds like a valvetrane flutter, on shifts at higher rpms. It never happened until about 5K miles ago and it's pretty noticeable. I'm open for ideas on this one. It's to the point where I'm wondering if I should take it in. It's not like it's slowly got to be this way; it just started, it seems.

 

My L has been doing the same thing. Only under boost, after going WOT. I took it in to a local dealer, they couldn't find the problem. They don't seem to bright! He said "we can't find the problem without a trouble code". I don't think it's internal. Seems like the boost valve or one of S/C control parts. It happens with or without a chip. Lloyd

------------------

2000 Black L #2189. Airaid & Superchip R9. Drag Results: Best ET: 13.07 Best MPH 103.09 Best R/T .501 (twice) Best 60' 1.631 on F1's 1973 Cutlass Supreme 455/450HP 4 speed. Too many Mods to list! 95 Olds Aurora 91 S10 305TPI/700r4 project 2000 freightliner FL60 Rollback tow truck My garage overuneth

 

Mine makes the same noise. I think it is the relief valve for the S/C dumping boost. It only does it if I get into the boost part way or when I let off of the throttle abruptly from WOT. WOT does not make the sound at all if I hold it open until I hit insane speeds .

------------------
Red '00 Lightning
#1388/4966
14.020 @ 97.97 mph B4 mods
A.R.E. LSII tonneau
K&N air filter
Mobil 1

 

Mine does the exact same thing but it has always done it and it seems to be getting louder. It is VERY noticable with the chip in and it is more difficult to notice with out the chip. I was figuring it was either the transmission or maybe detonation, I dont know. It definately has me worried.

Sam

 

I believe there is a TSB for the replacement of the two belts... something about vibration and/or chatter...

Any of you guys have the belts replaced?

Anybody know what kinds of sounds we would get if we had too much boost?

Piston slap?

 

Hello all..

Do not rule out detonation.. Light detonation can sound like valve noise..



------------------
Got Boost ?
1999 SVT Lightning

 

My L does it even when not under boost. For this reason, I'm thinking that it probably not detonation. It sounds to be around 50hz of frequency. One thing I did notice is that it comes on just before the trans shifts, then goes away and comes back just after the shift and goes away. This is within a time window of about 2 seconds.

 

Mine sounded like that also. one day it became a constant tick. I got a new engine. I was very unsettled by this (pulling engine in new truck). In reality I got a more powerful engine. That was Nov. 99. The dealer didn't even open it up.
Never found out what it was for sure.
Tom

 

There IS a tsb on this.I brought my truck in for this.I was having the exact same problem.I thought it was my valves or detonation.I had the exact SAME NOISE.wHEN YOU ARE ON THE GAS AND THEN LET OFF A BIT RIGHT BEFOR THE SHIFT POINTS IT WOULD DO THIS.It WAS the belts and I have not had it happen since!

 

Mine only does it after hitting WOT. sometimes it will take 2 or 3 times, then it will not go away until the truck has been parked for an extended time. I'm sure mine isn't detonation, belts, or the intercooler. Up till it hits boost it's normal, as soon as it gets past 0 into boost it flutters, until I let off. any sugestions? Lloyd

------------------

2000 Black L #2189. Airaid & Superchip R9. Drag Results: Best ET: 13.07 Best MPH 103.09 Best R/T .501 (twice) Best 60' 1.631 on F1's 1973 Cutlass Supreme 455/450HP 4 speed. Too many Mods to list! 95 Olds Aurora 91 S10 305TPI/700r4 project 2000 freightliner FL60 Rollback tow truck My garage overuneth

 

I've given my last post some thought and I'm beginning to think it is that S/C valve and not my belts because it does it right before an upshift under medium boost. Full boost, no, but then again maybe I'm not hearing it but I don't think it's doing it.

The computer is doing something right before a shift. I can't imagine that the little valve makes that kind of racket, but maybe it does. Mine sounds like a machine gun spitting BB's into a large, flat piece of tin. It's not only unnerving, it's embarrassing if people are around because it sounds like it's coming apart. Then, Lloyd, like you it goes away after 2 or 3 times.

Anyone got a mic they can hook up and try to pinpoint this thing? I wouldn't on a dare try to have the dealer find this. I bet clonetek wouldn't either.

------------------
Jim
Black '00
#1,757 built 3/30/00
Clear corners
J.L. Street program
J.L. Stage II ram-air
MagnaFlow Exhaust

 

no, i wouldnt think clonetek would want to go back to the dealer anytime soon, unless they wanted to drop his truck on the other side to make it match. its a shame when the person who has to work on your car/truck could care less about it cause they still get their same pay at the end of the week. dont get me wrong, there are a few mechanics who take pride in what they do and do very nice neat work, but there are way more who are just in it to drive the vehicles and get their pay. clonetek, im sorry about your truck too. dont give up and fight your a$$ off to get what makes you happy. : ) later all Mike

 

Sounds like to me it could be the timing chains flapping a little at the high rpm's if you think its getting worse maybe you can mention this...hope this help JL

------------------
93 cobra 10.90@127.00
99 lightning (black)
e.t. 12.41 @ 110.8
best mph 110.8
60 ft. 1.79
JL superchip
JL ram air
JL Powercooler
2# pulley
Level 10 shift kit
SuperChip Dist.!
(Man i love this truck!)
_ _ _________________ _ _
JohnnyLightning Performance
E-mail: jlightningracing@cs.com
WEB:webtechnik.com/johnnylightning

 

I dont have a tsb # but I can tell you at the time i knew of nothing about belt problems and the dealer was Well aware of it after calling svt and my dealership aint too bright.

I dont mean to sound like a know it all but i really am trying to help you.You NEED to get the belts done,This might not sound like the problem but i know exactly what noise your talking about and I had this problem.THIS IS MOST LIKELY the problem! Id bet $$ on it.I had this EXACT same noise and I only noticed it with a chip

 

Johnny,

No kidding, you're in Lancaster ,PA. I grew up in Gelnmoore (near Downingtown) and took the turnpike to school toward philly every day.

Heard those Amish have some "Super" buggy coming out that'll smoke your L. It does a whole 5mph and has 2 hp.

How's the weather up there?

Berto

------------------
00' Lightning/ Black
99' Lightning/ Red
94' Lightning/ Red
96' Cobra Convert/ Red