Blown Head Gasket??

[GoneCountry110]

Okay my 91' 2WD 4.0 5spd has 210K and still kickin, never had any engine problems, routine service and upkeep. Cold start up is nasty spits and sputters and revs to about 2grand for about 10-15 seconds then finally idles down w/o gas pedal persuasion. After running it runs real rich, just about clear out the garage instantly lol and does not idles smooth like before. I changed the plugs and the(im guessing) #6 plug the right rear plug was covered in black gunk, extracted all I could and replaced it. The truck ran perfect for about a month and I havent checked the suspicious plug again yet but all the bullcrap is back and is richer than before, not really noticeable power-wise, but is annoying as all get out.

HELP??

 

[rangerman84]

if it blows black smoke if you rev it it sounds like a oxygen sensor to me it happend to my buddys dakota he just got it almost looked like a diesel dakota ha ha but oxygen sensor fixed the problem and his rich runnin

 

[GoneCountry110]

HAHAHA I bet that was pretty funny. Nah no smoke at this point, but thanks for the help Im gonna check the oxygen sensor out.