It's a '98 4.0 aw4. I'm pretty sure the medium carrying the black specs is coolant. Gonna be replacing the water pump pretty soon. But why would there be black specs all over? I have also suspected the power steering pump as I replaced that quite a couple years ago and I think it may have been a bad pump. Also the Durango box came with red fluid in it (guessing at but didn't check what steering fluid Durangos use) so that could have messed up the pump...?

The water pump is getting replaced because when I started it this morning it had the lovely sound of a bearing going out and when I popped the hood and revved it coolant went spraying out lol. Once it heated up it stopped leaking /spraying though. Even took it through DEQ haha

Edit: forgot to say I'm not sure if the black is rubber or plastic or what...

 

ok this sounds crazy but some people put pepper in the water to stop a small leak...or it could be alum flakes thatwhere put in...people do strange **** instead of fixing it the right way..

 

Lol I've flushed the radiator already. Wasn't too dirty. Only the heater core was dirty. It's pretty fine stuff.

 

Maybe use a magnet to see if the stuff is metal or not.
If it's rubber it could be a disintegrating hose. I'd plan on doing new hoses when you do the pump regardless.

 

All hoses are new too... I was having an overheating problem a while ago so it got a new fan clutch, hoses, and a couple flushes. Good call on the magnet, I'll check that out before work.

 

Maybe a picture of the stuff would help too. Is there anything in the coolant if you pop the radiator cap (and overflow cap) when the engine is cool?

You could get disintegrating rubber from the overflow hose, radiator cap or other often overlooked component.

Once you know for sure if it's metal or non-metal, at least that will narrow down the possible suspects.

 

It's nonferrous. New water pump is in. I'll be driving it a little more, so I'll see if new crap gets sprayed on the engine or not..