What is this?

[Quinton]

First of all I am no mechanic, but I just bought a 2003 ram A couple of days ago that I’m trying to fix up. That being said I’m sure this is a stupid question but I was going to change the oil and I noticed that the filter and this plug was covered in oil, not sure if I have a leak but I can’t seem to find out what this plug is, any help would be appreciated

 

[Quinton]

I also found this in the gas cap.... definitely not supposed to look like this, how bad is this?

 

[rwwells]

top picture looks like oil pressure sensor

 

[Dodge 1500 4X4]

Oil pressure sending unit and you have moisture in your gas tank, replace that cap and get some (isopropyl alcohol) dry gas, not the one with ethanol in it and put a couple of bottles in the tank.

 

[kevkev]

My cap looked like that when I got my truck. It had been sitting for a while. I just scrubbed the cap out and its been fine for well over a year.

 

[4xdad]

moisture in the gas use gas line anti freeze methyl hydrate

 

[Quinton]

Oil pressure sending unit and you have moisture in your gas tank, replace that cap and get some (isopropyl alcohol) dry gas, not the one with ethanol in it and put a couple of bottles in the tank.

I guess I should have said that this is my oil cap not my gas cap

 

[Quinton]

I guess I should have said that this is my oil cap not my gas cap

moisture in the gas use gas line anti freeze methyl hydrate

It’s my oil cap, and it’s also in the down fill tube

 

[LoneWolf3574]

It’s my oil cap, and it’s also in the down fill tube

I've got a similar thing going on with my oil cap. It's nothing major if your coolant levels are constant. It is usually worse during the winter.