Most Relevant details:
'08 Touring, 140k, new to me

• It was given fresh oil and filter before I purchased, so I don't know what it looked like and it has full, clean oil and what looks like a Fram filter.
• Oil light comes on after it warms up or even after driving it, like, just out of the driveway. But it is not on at startup, only after a minute or so.
• Does sound like it's running rough when this is going on, and power drops significantly. On start up sounds clacky, smooths out after a moment, but when revved does not sound great.
• After clearing the codes that were on it initially, no new codes have popped up (but haven't run or driven it much because of how it runs).

Need to know what oil pressure should be so I can double-check what I was measuring earlier, and need to know what other diagnostics to try for the symptoms described.

Full story below.

So I bought an '08 Touring from someone who sounded like they were experiencing VCM-related issues. It's got about 140k on it, and the previous owner had told me that the oil light came on while his wife was driving, that he had it towed, that after it sat around a long while with nobody working on it he had them change the oil. He drove it home about 5 miles from that location and said it ran fine right up until he got home, when the oil light came on again. I don't know anything about the level or condition of the oil that was changed out of it, but this was with brand new oil and filter.

I bought it for a low price and he was very honest about everything he knew about the car and its condition, so for what it's worth if I've gotten myself into a situation it's all on me.

Anyway, when I checked out the van it started awful and drove awful for a minute, sounded so rough I didn't want to take it much further than the driveway. The oil light came on then, too. I pulled a misfire code on #4 and decided I'd get it towed home in the next couple days. The next day he had to move the van and said it ran fine, and when I came to pick it up there was no misfiring as I pulled it up onto the trailer - but there was a serious lack of power and the oil light was back on.

I checked and cleared the codes (the stored codes when I bought the van were P3400, P0455, P0456, and the pending codes were P3400, P0304, P0455, and P0456 - it's possible that I've mixed up which set of those was stored and which was pending), and I replaced the spark plugs. None of the codes have returned, but when I took it up and down the street I very quickly got that oil light again (and flashing, I think?), and the van was knocky and gross sounding. I stopped it and tried to coast back to my driveway for the most part.

My Foxwell NT530 arrived in the meantime, but frankly I don't know how to use all of this information yet. No MIL codes in the system, nothing stored in the engine/drivetrain/transmission codes (all systems clear). I started it up a few minutes ago to see what live data I could pull and the engine sounded a little clicky on startup but quieted down to a normal-sounding idle.

I tried pulling all the info from anything labeled an oil sensor. I know the oil pressure sensor is down near the oil filter, and that it has two rocker arm oil switches that contribute to the VCM system. Here's what Foxwell tells me:

Rear Rocker Arm Oil Pressure Switch - OFF
Front Rocker Arm Oil Pressure Switch - OFF
Rocker Arm Oil Pressure Sensor - 0.8036 V
Rocker Arm Oil Pressure Sensor - 13 kPa (I think this should actually be PSI, but the display said kPa).

This was all taken as the engine was idling and was...maybe just under mid-temp. For several minutes it idled without the oil light coming on, but as it started to reach temperature the oil light popped on again. No flashing and no MIL. As before, the dipstick shows full, clean oil.
Compression test returned about 200-205 on all cylinders (done while cold). I got an oil pressure gauge hooked up today and I'm not liking what I see. Starting from cold, it was idling around 10 psi - I stopped it after a couple minutes because I had to hop on a call, but when I came back to it later and started it up again, let it run for 6-7 minutes, it was lower than 10, and then when I was able to get my wife outside to help rev the engine slightly while I checked the gauge, it only got up to 10 at about 2k.

I took a short video with my phone, so you can take a look at the gauge reading and listen to the ticky tacky engine . (If it's not working I can provide a different link.)

Because the oil and filter are new and clean, I can only think that this means the bearings are the problem, right? My basic research pretty much says that if the oil is full, the pump is mostly creating the volume and the proper movement/alignment of the bearings creates the pressure. I've got a Honda filter I could throw on there for grins, and I could take apart the front VVT solenoid assembly to check its screen, but it's not leaking right now and I feel like both of those are probably wishful thinking--unless anyone thinks the solenoid itself might be stuck, and has ideas about what I could do.

I would love someone to tell me I'm wrong or to suggest a different test for me to try. If you tell me I'm right, I'd love to know what my options are - as far as I understand them, it looks like rebuild or replace, neither of which would likely be worth it, so it would probably be resell to someone who's willing to fix it themselves.

Many thanks!

P.S. - Before you ask, it is not muzzled yet, but if I can figure out what's going on with it and decide it's worth keeping and fixing, it's the first thing I'll get.

 

Oh geez, those rod bearings are toast! You can hear them hammering away.

They drove it for a bit with no oil.