So I was driving yesterday evening for about an hour solid, back roads, highway and hills. When I arrived at my destination I could hear a slight rattle/tapping/knocking noise from the engine bay. If I accelerated it would get a little louder, then go away. Noise gets softer/goes away after 2,000 rpm. Vehicle drives normal, no sputtering, no check engine light pulled hills with power at 3,000 rpms. I started it this morning after sitting overnight and the noise wasn't really present till it warmed up.

 

that sounds like it could be a crack in the exhaust manifold. I would pull the air box out and look for crack were the collector is near the flange. That is one of the main spots these tend to crack.

 

I'll have to double check, BUT it is a Brand NEW Manifold and gasket. installed last tuesday. I actually have brand new exhaust from manifold to tail pipe. All walker/atd parts

 

That's good to know. if you only put the manifold on on Tuesday, i would re torque the bolts. With a few heat and cool cycles the flange could have warped a little giving an exhaust leak. It sounded like it was louder towards the front by #1 cylinder.

 

I'll re-torque the bolts. I'm going to use a stethoscope later today to try and listen to everything. My one friend said it was loud injectors?? I do hear a little deep rattle as well I'll try to get another video at lunch if I can

 

Long rubber hose one end on ear other end in area of noise . Old school.

 

i look where the last mod/work was done,always!

 

I've been seeing a lot of post about flex plates cracking and sounding like a rod knock, would a cracked flex plate be more present once the engine was at operating temp??

 

exhaust manifold cracked?

doesn't sound like a rod knock. maybe lifter(s) ticking too, which isn't a big deal.

 

Nope, always cracked, not just sometimes!

The hose or stethoscope is certainly your next step.