We bought a 2004 Accord 3.0 V6 recently. J30A4 engine, BAYA transmission. 250,000 miles. It needed several things replaced. I put a new fuel pump, AC compressor clutch, rad hoses, timing kit/water pump, thermostat, rear upstream O2 sensor (air fuel mix), brake master cylinder, right side CV axel, cv axel seals at the transmission, Input shaft seal,, knock sensor, front passenger side hub bearing and ball joints and tie rod, 1 new ignition coil, fuel injectors orings and caps and cleaned, engine mounts, cleaned engine on the outside and cleaned the EGR passage and cleaned the intakes and intake passages of the heass of a considerable amount of sand, yes sand. And I have the engine out and I'm putting new seals and gaskets all the way around.

So, my question is, while I have the engine out, should I re-ring and replace the rod bearings, mains, and thrust washers? Cam bearings too? It doesn't seem to have any issues with knocking or smoking. We didn't drive it long enough to see if it was consuming oil. I dont know if I should just replace them while the engine is already out due to the milage or if it's better off with the factory rings and bearings if they arnt showing any issues.
and if I should replace them, should I use new standard size?? Or should I go 0.002 oversize? And if oversize, do I need to bore it and turn the crank? Or would it have lost that much from 250k miles of wear?
I havnt taken off the con rod caps yet, but the pistons rings to cylinder wall clearance at BDC is between 0.006 abd 0.007.
Also, there was a considerable amount of sand and oil mix stuck to the valves. So much so that it was causing a leak down of 35% on 3 of the 6 cylinders. Cleaning helped alot and brought the leaking to under 20%, and I will be lapping the valves. I didn't buy new valves or have a valve cutting done.
I don't know why there was so much sand in it. There was alot of it in the air filter housing intake tube. I imagine the front end ran into a pile of sand around the beach? The car came from Jacksonville Georgia. I dont know.

 

I would absolutely re ring the engine and put in new bearings if you already have it out, especially if you know you're experiencing leak down issues and the engine has had poor fluids.

I would make a decision once the walls are visible whether to bore the cylinders out, or to simply re hone them and re-ring. Unless there's big damage I'd just rehone the walls and gap new rings.

I'd get the crank polished but that's it.

If you're finding sand in the oil I would make damn sure to clean out all the galleys, possibly get a new oil strainer, new pump (I don't know if you already listed that), etc.