#5 spark plug caked with oil
Just bought a V6 4.0 '97 Ford Ranger with 50,000 miles. Engine ran fine. No noises. Exhaust appeared normal.
After less than two weeks began misfiring. Pulled plugs and found that the #5 cylinder plug was caked with oil causing it to misfire. Checked compression on all cylinders. Compression was similar on all cylinders including # 5 around 160. In the two weeks it used at least a quart of oil, but again showed no signs of burning it.
Found this post on the internet:
"Check your spark plugs for oil fouling in the center cylinders. ( 2 and 5)
Your intakes may need to be retorqued as the are often so loose the vacuum
will draw oil from the lifter valley, particularly in the central cylinders.
They burn so slowly that the exhaust is not even blue, but often the engine
pings due to carbon build up."
All of the intake bolts were loose, the worst was over the #5 cylinder. Re-torqued bolts. I've run it for probably 50, no more than 100 miles and it's used at least half a quart of oil and the #5 plug is again building up oil and carbon residue.
Any ideas on what might be causing this?