Question about oil pressure control valves on 5.7L engine

My truck is a 2010 Toyota Tundra SR5 with a 5.7L engine (299,000 miles). I recently changed the timing chain on it after watching several YouTube videos. After bolting everything back together, it actually turned over and started! I then took it out for a test drive, and when I reached 70 mph, something jerked and it went into “limp” mode. OBD scan codes were as follows:

P0300 – Random misfire

P0018 – Crankshaft Position – Camshaft Position Correlation (Bank 2, sensor A)

P0021 - camshaft position A

I feared the worst, that the timing chain had “jumped”. Also suspecting the oil pressure control valves, I swapped the two on the passenger side with the two on the driver side, and got the same codes. I couldn’t think what else to do, so brought it to the Toyota dealer. They replaced the two oil pressure control valves on the passenger side, and now the truck runs like a dream! My question is, why did my diagnostic exercise to swap the two oil pressure control valves on the passenger side with the two on the driver side not change anything as far as OBD scan codes? How did Toyota’s replacement of the two oil pressure control valves on the passenger side fix the problem?

 

If I remember correctly, there is a vvt oil control valve filter on each side, might of been the problem and maybe dealer replaced or cleaned it same time as the control valves would be my guess?

 

Impressive work on the timing chain job. How many hours did it take, and can an average DIY guy do it himself?

 

Actually my question would be why did you replace it. Shouldn't it be a lifetime part? Why mess with it unless it had an issue?

 

I have heard of instances where timing chains and or guides fail on these things. I’ve heard of rattle issues, etc. Thankfully it’s not common, but can happen.

 

I mean sh*t can fall from the sky. A lot of things can happen but the reason for having a timing chain is to have it as a lifetime part. No reason to change it. This is a Toyota, the issue are mentioning is not a common issue at all. Else Toyota would have recalled these engines. Sure maybe 1 in 20000. And even those maybe attributed to engine maintenance.

That being said I have had mostly timing belt engines all my life so when you compare those engines to timing chains engines - the chain ones are a lot more rattley (if this is a word). This is especially true during startup. All kinds of things rattle but quiet down in a minute once the oil is fully circulated. I would have made sure the engine actually having some issues before trying to do such an extensive overhaul if it.

My truck had 281k on it right now. I would absolutely make sure that it has issues before I go into the time and effort of replacing the darn timing chain. Do it only when absolutely necessary. Just my 2 cents.