Raben

iTrader: (5)

Ok so we installed a 408 on a 98 Vette and checked everything and anything I keep hearing this damn sound ( sounds like a flute)that sounds like its coming from the throttle body I thought it was a leak in the intake gaskets so I bought new ones and also bought new TB gaskets installed them and the damn flute tone noise is at it again. It almost felt like it was coming out of my TB solenoid so I ordered a 90mm Ls2 TB still waiting on it. My tech is out of town and I cant seem to figure it out. I did go with the wiend Lingenfelter intake but its nicely sealed. My question is since im not experienced in this department..Those two black plugs under the intake(Block Plugs I guess) if they are not secure all the way down will it make this noise? And would a bad solenoid or TB all together make this noise? Out of answers or clues please help!

GuitsBoy

iTrader: (4)

The two black plugs under the intake sound like knock sensor harness boots. The knock sensors shoud be torqued in snugly and should be sealsed, I dont think thats your noise. If the motor idles well enough you could spray carb cleaner around the intake and see if the rpms jump slightly. Or take a cigarette (or incense stick) and see if the smoke is pulled in through a leak.

DaddySS

Carb cleaner or lighter fluid are excellent tools for finding vaccuum leaks. spray or squirt around suspected areas and the RPMs will usually change when you find the leak. Take your time to locate it, parts swapping is generally the least effective method.

PREDATOR-Z

Is it one of those cardboard gaskets for the TB?
if so you need to cut out the part where the Idle sensor outlet is to the form of the TB outlet. If that gasket covers that area it will whistle. I had that issue with a BBK TB/gasket when I had it on my stock LS6 with a spacer.

JoeyGC5

iTrader: (24)

Its not from air being sucked through the airfilter at the front is it? As my vette sounds like a damn Hoover vacuum sometimes, if theres a deflector or wall close by.

Raben

iTrader: (5)

Yes it is a paper gasket though it already came with the two top holes cut out on it??? I guess I can go ahead and look at it again and make sure this works out ok. Atleast I know its not the lock plugs. Though last night I noticed something new. The little bit of a gap there is under the middle of the intake and the block where the knock sensors sit I covered it with plastic wrap just for the hell of it to see what happened and the noise went away. As soon as I started to removes the wrap the noise started coming back. Well I guess since Im having to take it off again im going to go ahead and sell the Weind and get an LS@ intake to match my LS2 Throttle body Ive waited long enough might as well keep waiting.

PREDATOR-Z

You can buy a 90mm mouth LS6 intake from TPIS. Much better than a LS2 intake, nearly matching a FAST performance.

Raben

iTrader: (5)

How much are these I am in the process of buying one right now I just sold my lingenfelter.

PREDATOR-Z

Check TPIS site >>>> sponsor

Raben

iTrader: (5)

I checked it out too pricey for me I can get an LS2 for 200. I dont mind it at all but thanks.

Raben

iTrader: (5)

Haha you have a kick *** turbo though

Sigforty

The only real vaccum leak location I know of with the Vettes is the hoses that run under the battery. If the battery leaks or ever gets damaged it will drip acid on those hoses and eat them up.

Raben

iTrader: (5)

TY I will check These?

JoeyGC5

iTrader: (24)

Nah just a nitrous motor with a big cam. Have you used the carb cleaner trick from the air filter all the way to the MAP sensor? Just to verify no leaks at all.

Raben

iTrader: (5)

Nope I will tomorrow I went to the LS2 setup completely withthe intake and if it persists then we will see.