When is it rods and not injectors making that noise?

[ORCoaster]

Lately I have been driving slow through town with the windows down and have heard this nasty noise at low RPMs.  Like between 1200 and 1800 RPMs.
I don't hear it once I get passed 2000 for sure.  I have tried to source out a sticky injector in the drive but the real noise comes just as I put a load on it at the lights or stop signs.  I don't hear it coasting or decelerating downhill. 

I am beginning to think it is a rod to crank noise.  So what is the test for that?  Pull the oil pan and get on the bolts to be sure they are at spec?  Before doing that would you think it would be advisable to push, pull or tap lightly on them to see if they move? 

Looking for something to do the next weekend it stays dry.  Let me know what you may have found if you have done this sort of chase in the past.

 

[RabbitJockey]

its probably the effects of timing and load, probably normal, you could retard it and see if it goes away, where is your pump timed?

[Dakotakid]

If you truly think it is bottom-end related. Nothing beats pulling the pan,  pulling caps, and reading shells.
I don't think a séance is going to help.
Is this the engine you cobbled together a couple years ago when you lost one piston or whatever?

I would start with #1 cap and rod cap. The last to get oil.

[ORCoaster]

Rabbit-  I have it timed at just a little over the 88 mm spec.  I think I have it at 93.  So not thinking retard will change it much.  I don't think I am running over advanced on accel.

Dakotakid-  I think I am in for pan pulling and throwing the shells to the driveway and reading them like tea leaves.  A few years ago I did loose compression in the third cylinder and that was fixed with a new set of rings. 

I think it is on the front end that I hear the worst clang when cold.  But I am running 100 to 70 psi at the head on a mechanical gauge.  But that doesn't mean all passages are getting oil as they should and don't have excessive wear. 

Thanks. 

[fatmobile]

 If the injectors are banging it usually means they are pissing a stream.
 Sometimes clear lines between the injectors will show air coming from an injector that has micro-channeled.