Possible rod knock...

[GIGrunge]

So, just got a 1996 Ranger with the 3.0 litre engine, manual transmission, 4x4. I had out on some trails on Guam (I'm stationed there, Air Force) and I found a nice open area so I decided to really open it up and do some donuts and have some general fun with my friends just to see what it was all about. Needless to say, my gauges read as having no oil pressure, so I turned it off, and turned it back on, and everything was alright, no big deal I thought. We kept on having fun, and the oil pressure went again, then we heard a slight thumping/rattling noise. So I kicked the vehicle off, and then it wouldn't start again. It gave the symptoms of a dead battery, however when my other friend came out with his Jeep, we couldn't start it. We tried push starting it down a hill with 4 wheel drive engaged with hubs locked, we tried a few different methods, and then cranking finally while I was rolling finally did the trick and we got it to turn on. Drove to the gas station, where the thumping noise persisted. It wasn't loud and didn't seem like anything more than a minor problem. Drove it around the rest of the night, thumping slowly turned into a knocking noise, which at first went away in forth and fifth gear. At times, the knocking noise would be consistent with the engine, other times it seemed random. Finally on the last leg of my driving it got louder and louder, and bottom line is my friend and I believe it's rod knocking. Anybody had this trouble and could give me some advice?

 

[rcpilot24]

it sounds like a rod knocking. Did you check the oil? possibly damage the oil pan? lots of variables here.

 

[GIGrunge]

Yeah I did. And it actually smells a little bit like fuel/oil. The oil pan seems to be fine, no damage done. Just another info note, I tried to see if I could pin point the area of the problem, so I removed the spark plugs one at a time, and the knocking still persisted. Also, unless there was some damage done already and the cylinder wasn't operating anyways, I had noticed that despite the knocking worsening, engine performance hadn't worsened at all. I don't know if that helps give a clue to anything.

 

[Jason_J]

Do you have any squealing, like squeaky fan belt squeal?

 

[GIGrunge]

That's a negative. Just the knocking. Another thing to note, the engine is running rich, upon noticing this when I purchased the vehicle I assumed it was the O2 sensor or possibly it's age. Once again, not sure if it's at all connected to the knocking issue, or if it can help pin point anything.

 

[rcpilot24]

You removed all of the spark plugs? even if one cylinder was not firing you would definantly see a difference in performance when you removed a good plug. I am assuming all of the testing was done with each cylinder on a refire basis. You were not removing plugs with the engine running. everything still points to a bad rod bearing or spun crankshaft bearing.

 

[GIGrunge]

I had removed each spark plug one at a time with the engine running, and there was a slight difference in how the engine had been idling, however, the knocking noise was still present.