Very loud knocking when rpms increase??

Ive got a very loud knocking sound that increases with engine rpms.
I cannot tell if its comming from the engine or the transmission.
I have inspected the tranny mount and engine mounts and I dont see anything obvious, I replaced the tranny mount and one of the engine mounts about a month ago.

I have also pulled the inspection plate off and checked the bolts and the flexplate and everything is tight and looks good.

As the rpms increase the knocking gets louder and louder, if I take my foot off the gas it goes away. I cant imagine it being a rod because its so loud i think it would have blown through the block by now, LOL.......
Someone told me it sounds like the Torque converter may be bad, What does a bad torque converter sound like?
And where should I start to diagnose this problem?

Thanks for any help.

:repair:

sounds like a cracked flexplate, still. It's pretty tough to inspect the ring where it bolts to the crankshaft and the symptoms are just as described.

I wouldn't rule out rod knock. I would tear off the oil pan, then pull the rod caps and main caps to inspect the bearings and journals. If you catch it quick enough, you might get by with a bearing swap, or at least an overhaul, instead of a whole different motor.

Flexplate knock tends to come and go depending on the rpms.

I just went out and started it up and it made what sounds like the same noise right at startup and then goes quickly goes away or if I give it gas. (while idling)

Would the rod knock be there all the time?

I could drop the pan but I wouldnt know what I am looking for. If it is a rod or worn bearings I would still have to pull the engine for an overhaul, right?

Thanks.

Either knock can come and go.

Stethoscope on the oil pan, flex plate cover area should narrow it down.

Take a look at your harmonic balancer as well. Start your engine and see if it is wobbling as it is spinning. Mine bit the dust 3 years ago and was making a similar noise to what you are describing.

The last time I looked for a knock I used a two foot piece of one inch diameter plastic tubing (Plastic wiring conduit). It took me awhile but I finally located the sound to within maybe eight inches. I was actually able to localize the sound to right around number five connecting rod.

Like I said it took multiple tries to get it right. I'd listen for awhile, then take a break and listen some more. The problem is sound travels and nailing the originating sound and not the harmonics or an echo can take some time.

Be careful not to get tunnel vision and stick that tubing into some rotating parts.