My motor is making a funny rattling noise coming from the mid-lower front of the engine. It's erratic at idle and becomes more pronounced when I increase RPMs. I pulled the plug wires one at a time, disconnected belts, checked timing, plugs, etc. and everything seems in order. Compression check too. I have a 25 second video of the motor running where you can hear the noise. Is there anyway to post a video on this site so that the experts here can help diagnose?

What engine?

440 six pack

Put it on youtube and post a link to it here

Auto trans? wouldn`t hurt to check the check torque converter bolts. Use a piece of hose to try and isolate where the sound is coming from.

4-speed. I'll try posting on you-tube and link it.

I'm unable to post it on you-tube, or even e-mail it to myself. File must be to large. GRRRRRR

Total shot in the dark guess, but if its got a hydraulic cam there have been a LOT of hyd lifters going bad lately.

What is the history on the engine? Recent rebuild? Did the noise start out gradual and got worse? Did the noise start after running it hard or sitting for a long time? Just trying to help diagnose.....Scotts idea on the lifter is certainly a good possibility

What harmonic balancer is on the motor? A/C car?
Pulling the belts off would eliminate the alternator & water pump.
I'll assume you've already checked the fan & pulley for any wobble.
Does it sound like a bad bearing, or a rhythmic ticking, or contact between a rotating item and pan or tray?
Definitely from the front?
Does it change with clutch pushed in?
Might want to pull valve covers & poke around, though you said "middle front".

Scott, it does (509) and it's relatively new, about 2 years old. I've had a bad lifter here and there, and it produced a ticking noise under the valve cover. The noise I'm hearing with this problem sounds more like a pre-ignition rattle. Very erratic, mid-lower front of motor. I'm about ready to pull the timing cover and pan. Sucks.

Bummer but better to find out now than after further damage. Maybe a wrist pin. If you pull the plug wire to the offending cylinder while it's running the noise will likely stop if it's a bad pin.

No wobble with fan or pulley.
Not rhythmic, more like an inconsistant rattle, like pre-ignition when you hammer down with crappy gas.
90% sure its from front.
Didn't check it with clutch engaged, good idea...

Scott, pulled each plug wire one by one and noise remains. Although it got slightly louder when motor warmed up.

Not sure of history on rebuild except it got a cam about 2 years ago. Only owned the car for a few months and the noise hasn't changed, but only put about 50 miles on the car.

When it got the cam

Was the oil slinger installed backwards on the crank ?

Wonder if it's with the timing chain and/or oil slinger (assuming they put one on).

I had a video of what my Dakota sounded like when it's chain was hitting the cover, but, photobucket was kind enough to delete it for me.

If your video is only 15 seconds long and won't upload, it sounds like it's formatted wrong.

What do the plugs look like?
If black, maybe carbon build-up on the piston giving a knock when warm...

Joe

Go underneath and check the pulley to harmonic balancer bolts. You may have one or a couple bolts too long making them scrape against the timing case cover.
Had this happen on a 68 Roadrunner with 383. We did a new rebuild. On start up we get this noise we could not find.
With the engine off, went underneath , noticed that the pulley to harmonic balancer bolts were too long and scraping the cover. We put shorter bolts on and no more noise.

After a new rebuild and learning it was just a bolt... wow that stinks. I'll check the bolts tonight.