I'm looking for input on some engine noise. I'm convinced it's a new noise, but a couple friends think I'm being paranoid and that it's just the loud LS valvetrain due to my cam. I can't hear anything abnormal at idle or find anything with a stethoscope at idle, but any engine speed above idle and this noise is distinct. Hot or cold doesn't matter. The car has a BTR stage 2 cam, BTR springs and pushrods, LS7 lifters, and long tube headers. Any input?

 

I hear nothing abnormal, at least from this video. Our valve trains are relatively noisy, I would not call them at all quiet, especially if you have headers. You need to give us more video however, because diagnosing over a video is near impossible especially with the video being shot in the cabin, noise travels in non-intuitive patterns and you really need to have someone else throttle the car while you move your recording device around different parts of the motor you think might be emitting questionable vibrations. Even given you do that, it is of questionable efficacy due to microphones and speakers being no where close to what the human ear can pick up and interpret. Is this in your garage? You have all kinds of messy vibrations interfering with the clarity needed to even make a mild assumption.

 

 

Try changing the engine oil to 10w40. Thicker oil helps with lifter clatter.

 

Thanks for posting the video. Without a significantly better microphone, significantly better placed ... with no evidence to the contrary, I'd call this "standard valvetrain clatter."

You've taken an engine that has a fair bit of valvetrain clatter, changed up the valvetrain a bunch, and then installed long tube headers which are known to magnify the noise. I'm not saying that means you're only hearing standard valvetrain clatter, but that's my best guess. If you're concerned, bring it to your local speed shop for them to diagnose it.

 

I recorded from the cabin for a few reasons. Mainly because I was on my own, but you can also see what I'm revving to, can see good oil pressure, what temp the engine is at, etc. This is in the garage with the door open, and honestly it's a pretty good representation of what the car sounds like in person.



I've been running 10w40 since the mods were installed.

This is where I'm stuck. The build isn't new, it was done over 5 years ago by a top notch shop that I no longer live near. What I hear and what I think the video captures is a distinct tick or knock that stands out above the typical sewing machine clatter that I'm used to. Like I said, I'm convinced it's new in the past few months, but I can't figure out what it is. I've pulled the valve covers and checked the rockers for tightness and torque, then I pulled the rockers to inspect the pushrods and found normal/consistent wear. I've also replaced the header gaskets and checked the exhaust for leak tightness using a shop vac blower and soapy water. I even cleaned the air injection check valves to rule them out.

I think a shop would want to pull the heads and throw new lifters in, which I would be ok with if I had some confidence that there would be improvement. I would actually do that job myself. So I guess what I'm looking for here is input on if there is noise from the early stages of a lifter failing, or speculation on a different root cause.

 

I can hear the distinct clatter separate from normal engine sound; however, I noted the temperature was not up to normal operating temps...looks like only about 130+/- degrees...like to hear the engine at 200+ degrees? You mentioned engine temperature has no effect. With your mods, perhaps this is normal?