Spark plugs filthy after around 1000 miles

[801FJ62]

Pulled my plugs today on a whim after around 1000 miles being put on them. The electrode is tan, but the threads are full of soot and oil. They are Bosch platinum plus pugs, they seem to be doing their job just fine other than this. Is this likely a problem resulting from me not using the OEM plugs, or something worse? Thanks

 

[Wile E Coyote]

Dirt air filter, bad O2 sensor, bad tps (but you'd notice other symptoms on that one) would be my first few checks. If it was caked on crud I'd blame pcv or bad rings but viewing the pics on my phone it looks like soot from a too-rich condition.

 

[801FJ62]

Thanks for the reply. I had the head rebuilt on the engine around 1000 miles ago at the same time, along with a new air filter, PCV valve/grommet, dizzy cap and rotor, wires and plugs. Is there a way to tell for sure what is wrong? Is this something that should even be corrected? The truck has plenty of power and is getting around 13 MPG so it seems to be operating alright...

 

[TS888]

Sometimes with platinum plugs you need to play with heat range to get the same results as standard plugs. I'm running NGK platinums that are a couple ranges colder than stock, they've been fine in the summer. I may need to bump up a range or two when the weather gets colder.