Nice, yeah give us the setup

 

long tubes and a lt1 with ath350 trans
with a lil suspension not much here guys

 

i sounds like its fromt he back but i dont have egr
thanks for the tip tho

 

Did you check the plugs? You need to pull the plugs out completely and check them for being crossthreaded. I stake my bet on it being an exhaust or compression leak.

 

I currently have pretty much the exact same sound in the exact same place. It wasnt always there. It just kinda popped up one day. Ive had the same gaskets and stock hardware that came with my hookers on for the last 4 years. I figured it was only a matter of time before I blew an exaust gasket. So i gotta say, Im under the impression that my sound is a bad gasket, so im gonna go ahead and say that I think that its your problem too... im telling you it is the exact same sound.

oh and besides the sound, my performance is right where it should be (besides the failing opti)... good luck figuring it out.

 

Agreed. Sounds like exhaust or compression. Do you smell excess exhaust in the engine compartment?

 

I doubt that it's a crossthreaded plug because those holes are nearly 3/4" deep and if it's crossthreaded, it isn't going in very far. The plugs ought to spin almost all the way in without a wrench. He ought to know if it's a screwed up plug cause it would be sticking out like a sore thumb - but that was more common with the older style 3/8" or 1/2" reach plugs.

Now, a really loose plug can make a racket, but, again, thats easy to check for.

One other thing is that a leaky plug wire can make a snapping sound as the spark finds ground to the engine or header. Check for that in the dark.

 

Sounds to me like an exhaust problem. I had one just as loud on my 6. Inspect your manifolds for cracks in the welds, small holes, and recheck your EGR (block offs) are on tight. Another thing you can looks for is excessive black residue, from the leak. Keep poking around your car didn't come with a tick... it just takes time to find it i guess lol.

 

Everyones advice is really good. Heres another trick. Try using aquarium tubing or something similar to listen for exhaust leaks. I had a couple exhaust leaks that I was plagued with for 6+ months. I used a tube to listen around with finally, and found them in 2 minutes. If it seems like the noise is coming from under the valve cover, pull the cover and use the end of a screwdriver against you ear and the tip on the rocker studs to listen for valvetrain noise while the car is running. If the noise increases when you accelerate, its probably exhaust related. If the noise stays at the same level, its probably valvetrain.

 

install some LS7 lifters. Quietest HR lifters I've used yet

I've also found leaks, like a pinhole in a longtube and gaskets that dont adequately seal to the head. Also found that sometimes non gasketed plugs that are loose (dont overtighten!!!) can leak if loose.

 

hang on u can put ls7 lifters in a LT1, where do purchase? Got a P/N

 

did you use new or the original pushrods? to me it sounds like my car when it had a bent pushrod.

 

You can just do a search, lots of GM dealers on the boards with contacts that will sell GM parts to your door. I always used Jason Chromer without a problem. Costs about $100 a set new and are quieter than even my OEM replacement comps and cranes...and the GM ones.

Lots of people are quick to spout off that nothing on an LS1 crosses over. Most things dont... but the LS1 style engine uses the same type of lifters. The C5 Corvette auto's can even use an LT1 torque converter!

Next time I build a 700 Im going to try one and see how I like it on a near stock engine

I dont have a part number but you should be able to just call and they should already know it.

 

there is two types of ls7 lifter, the stock ls7 #12499225 and the race #88958689. The racing ones are $219 from gmpartsdirect.com.

 

Your egr block off on you header is leaking bad.
Mine made the same exact noise. When you take the plate back off check for black soot.
If your plate is covered in soot, then you can do 2 things.
1. take your header off and cut the egr tube off and weld it shut.
or
2. Buy an exhaust tube gasket spray it with permetex copper seal and bolt the block off back on. See if this works.
If not, then go to option 1