mr08353

LS3 in my 2013 Camaro developed a random backfire and at the passenger front of engine a dead knock can be heard about every 5 or 6 seconds. Similar to what an A/C clutch sounds like when it's engaging. Someone with more experience than me heard it and suggested s broken spring. I took valve covers off and nothing readily noticeable. Is it possible that a broken spring would generate a random backfire and if so, wouldn't the break be noticeable? I guess the next step is to physically remove all springs for closer inspection. Any thoughts or ideas???

farmington

iTrader: (14)

is it still under warranty?

mr08353

Lol. Nope. Too many HP mods. I'm on my own on this one.

farmington

iTrader: (14)

maybe have someone crank it while you have covers off and you look and listen

racecar

Pull the valve covers, get a small mirror and flashlight. Look at the springs very carefully.. One could be broken close to the bottom, on the back side where it is hard to see. Just like a broken brake rotor. You always expect to see it front and center. If it is on the back side and down low, very hard to see. OR: Bent pushrod???

mr08353

Ouch. Lol. You would have to mention a pushrod wouldn't you? Haven't done anything to bend one of those. Easier to check those than pull all those springs off. Still tempted to let it idle w/o the valve covers on them and see if I can get a better look. Just hate to make a mess.

racecar

OK, Take the covers off, take the spark plugs out, crank it with the starter and listen for the noise. Use a jumper on the starter. Don't turn the key on and crank it. You would have fuel and spark coming at you.

BMR Sales2

iTrader: (40)

The first thing I would do if you think it is a broken spring is get the valve cover off and visually inspect the valve springs. If you have a broken spring/s you can generally see it pretty easily.

MuhThugga

Broken valve springs are pretty easily seen. This wouldn't be the first time a lifter took a **** in a LS engine, though. If you still have a warranty on the car, I wouldn't even bother with anything other than taking it to the dealer to get fixed.

Working on cars is fun and you get to beat on your chest and all that jazz, but only a fool wouldn't use a warranty.

mr08353

Warranty is no good. Too many HP mods. Dealership would only laugh at me.

mr08353

Sure. I've done that. All the springs look good. That's why I'm confused.

mr08353

Good idea. Thanks. I will definitely try that.

MuhThugga

What kind of mods?

mr08353

Headers, cam, new heads & valve-train