Metallic noise then vibrations

[Wauzbert]

Hi guys,

maybe you can help me on this one.

Some weeks ago after I started the car I heard some metallic noise, just as if a screw nut would have been knocked away. I'm pretty sure that since this incident my engine is vibrating in two RPM frames, 1.800-2.100 RPM and above 3.000RPM in neutral.

I'm really concerned that I have to spend tons of money for repairs again just after the car was running just fine for a year. Could you give me some ideas what could cause these symptoms?

engine is an internally balanced 440
Flexplate B&W 102301
TQ Converter around 3000 RPM stall (make unknown)
Damper, Fluidampr (internally balanced)
TF727 with manual valve body (cheetah) shifts really soft

If something is broken inside the engine, would the engine react like described? I found a statement that if something is wrong with the balance inside the enigine the vibrations wouldn't be limited to certain RPMs.

Do flexplates or a TQ converters for internally balanced engines have wheights, too, which they might loose?

A friend of mine considered the mains as a possibility. Valid point?

Thanks for your help and regards from Germany
Volker

[Chryco Psycho]

It could be anything , did the metallic noise sound muffled as if it was internal , if the oil pressure is the same I doubt it is internal , more likely something in the trans or converter , converters do have weights but it would vibrate with them on if the engine is internally balanced , maybe a converter bolt coming loose & hitting the rear of the engine & breaking the flex plate 

[Wauzbert]

Thanks Chyro Psycho, that gibes me some hope that I dont have to pull the engine.

No, the sound was not muffled but bright and clear. The oil pressure didn't change and is still around 60 psi. The flexplate is still intact. I checked it and it still has all of it's bolts in place.

But if it's something around the Converter I can check it, though I dont like the idea of pulling the tranny as I've never done that before. Well, it had to be done (and I had to learn it) at some point anyways... 

Thx

[Chryco Psycho]

Just trying to think where else it could be , if the converter was not fully seated in the trans it could be an issue with the trans oil pump but generally the trans would not work at all , removing the trans pan might reveal something . If it vibrates in Neutral the only thing moving is the crank , converter , input shaft in the trans & the pullys up front , if the crank was welded to add weight I suppose the weld could have let go & the weight came loose from the crank inside the pan but I would expect the sound to be more muffled but you could drop the oil pan & look inside .

[mopar jack]

Put a wrench on the converter bolts and make sure they are tight. Also if you still have an inspection cover there make sure it is not bent and touching the converter bolts.

[Rich G]

Check the flex plate and make sure it isn't cracked. They do crack and make strange noises