I have a 2008 12 passenger Ford E-350 with a 5.4l gas engine, about 80000 miles. It recently started knocking pretty hard, it sounds as if from the bottom of the engine, to the rear. I'm in the process of raising the engine so I can remove the oil pan to inspect the rod bearings. I have removed the valve covers, and I'm about to remove the radiator/fan cover so I can then remove the timing chain cover. I want to see what the timing chain guides look like, since I have so much apart anyway.

Do you guys think I'm on the right track as far as what I think the problem is (one or more rod bearings)?

Does anyone have experience with a similar issue, how did you resolve it? What was the cost?

I have been encouraged to post this here, from the full size van forum. https://www.ford-trucks.com/forums/1...-350-5-4l.html

 

Unless you have a cracked or loose flywheel, it sounds like a rod bearing have have failed.

 

Well, I finally had time to tear it apart. No problem with the timing chains/tensioners at all, it is the connecting rod bearing for what I think is #4 cylinder (or #8). Either way, it was the second bearing from the back of the engine, quite a bit of play, all the other bearings are perfectly tight.

Is it completely wrong to just replace the failed bearing, if the crankshaft looks good? Run it for a few days and change oil? Am I just delaying an inevitable crankshaft replacement? In the worst case I'll just be back where I am right now, right?