scottie350

Ive been looking at that kit, how loud was it w the SE mufflers? Mostly at cold start? 530am starts wondering how POd neighbors gonna be lol. As for the valvetrain i likely hear it so much bc im focusing so much on it when driving, but yeah def at drive throughs ill deal w that later haha

Btw just realized ur using SE LTs, is ur exhaust thier true dual kit also?

I normally dont keep my vehicles long. My intention was to get some more fun out of it while i had it and then swap it back to stock before i traded it. So looking at dynos done settled to save cash as i knew id get that. Im not worried about longevity, theyll last just fine aslong as im gonna have the truck. I had the headers stripped and coated myself, the extra 300 for the ceramic they send it in isnt worth it from the countless hours searching i did, it tends to chip off as ANY bump can damage the coating in transit, got em coated locally for half the price. Given the gauge of metal used i was curious if others hear this or if i was missings something. Oddly i could only find searches leading me to the vette forums but they said the same thing over there about the ls motors and headers/catless... valvetrain noise. The video a forumer there and his explanation of the conditions confirmed thats what im hearing. Ive modified most of my vehicles, some quite heavily, never heard this before without finding a problem, first time on an ls engine so its been bugging the hell out of me. Not finding a culprit i needed to know if it was a normal noise or if i was overlooking something. Seems its normal though, and either ill have to learn to live with it or try the rocker bushing upgrade that Marcus posted

Welll crap, it drives me nuts, i may have to do the upgrade. Im super ocd about some things.

Yeah this has been my consensus recently. Most info i find on the vette forums but guys have mentioned this noise from ls engines. One guy posted a vid and its exactly what mine sounds like. Normal at idle and even in park revving, notice it at higher gear/low rpm under load. Havent found a confirmation if a true dual with x pipe will lessen it, 300blackout says doesnt have this noise w his setup. Ill check out the kit you posted. Thanks for the confirmation Marcus, at the very least, perhaps i just need a louder exhaust baha

Clipped mine to keep the plug in so it doesnt ruin the plugs in the harness, then tuned them out. If ever need to i can splice the o2s back on.

Thanks for the reply. Mines custom tuned with v4 shut off. Sound doesnt come from engine, dominantly radiates from the y pipe. Something ive been considering is where it ys into single pipe causing the increased noise. Because it seems to be radiating from the y pipe this seems logical. Ive been wondering myself if going to duals with an x pipe would drop this off. By your setup i could be on the right track. Im going to take the truck to the custom exhaust shop and have him take a look and then see what he thinks.

Hey guys, so this is on a 16 Sierra 5.3. After going to LTs and catless y pipe i seem to have whats best described as a loud sewing machine sound. I know stock manifolds are thicker which equals more valvetrain noise but is everyone just dealing with this obnoxious noise? I cheaped out a bit and went with pace-setters but i did have cause. Ive seen several dynos of huge gains on pacesetters on these trucks and reviews from guys saying theyve lasted them several years and still going, which by then id be into a new truck anyway. Ive checked for a leak leak, loose plugs, caps, nothing i can find. Thinking pacesetter headers and y pipe gauge size likely thinner ive been searching. Oddly enough PS are the same or thicker gauge than most recommended brands. Which is where im now stumped with this sound. It doesnt come from the headers, it primarily seems to reverb through the y pipe area. Can hear it at cold start, or at higher gear low rpm cruising from beneath the front seats, like a loud ass sewing machine. Ive seen posts on the vette forums that this tends to be a tad normal over there with catless LTs, not much on these trucks tho. So what, is this common and u guys deal or? PS uses 16 gauge on the lts and 16 gauge on the y pipe, kooks are 18 gauge LT and 16 gauge y pipe. Honestly super annoyed with the sound, ready to put the stocks back on thats how annoying it is to me.

Hmm thats quite a bit off, ill stop tomorrow and see about getting some samples. I was looking at trading my truck so i hadnt done nething lately but i think im keeping it so ill take a look and let u know if i get a chance Sent from my SM-G900W8 using Tapatalk

**** thats a good price man Sent from my SM-G900W8 using Tapatalk

It's been apparantly proven that they can definitely be seen even after returning to stock Sent from my SM-G900W8 using Tapatalk

4800kms on mine, wish I had gotten a catch can put on right away when I bought it at zero, It'll be there by the time.i get home from work in a couple weeks, and then intake cleaning will ensue moments after install. Sent from my SM-G900W8 using Tapatalk

And as stated, there is some things you can do, injector flush being one, I'd do it immediately after installing a catch can( these DI engines basically require them, or they should, oil going back through the system and bungling up lifters is common place with DI). and run at least 89 octane. All assuming any check of engine codes and stuff uve had done ect turns out fine. Once you've done the flush and changed fuel, go from there Sent from my SM-G900W8 using Tapatalk

Also I'll tell u right now, my 15 has the loudest aftermarket exhaust and it doesn't shake a damn thing lol take it to a different dealer Sent from my SM-G900W8 using Tapatalk

Throw high octane in it, and see if it smooths out. It's been found that these engines are pulling knock on 87 octane, at 11:1 compression, it's understood why, a lot of ppl have been finding running 89-91 octane made the truck run significantly better. That doesn't help, bringer to the dealer that's what u r warranty is for man Sent from my SM-G900W8 using Tapatalk