Good idea. I guess it wouldn't hurt to ask about it. The vehicle has had regular oil changes. Not sure where the sludge would come from.

What are you guys thoughts on something like this...

TOYOTA 4RUNNER LEXUS GX470 4.7L ENGINE 74K MILES 2005 2006 2007 2008 2009 | eBay

If I went this route how many labor hours should I be looking at?

im parting out a complete running engine from a 05 gx470 here in california. you can come fire it up and drive it if you want to check it out.

Good info, bad situation. Blockage of an internal oil passage is a rare thing on properly-maintained engines. If the shop is seeing the engine clean enough to rule out sludge as the cause, then a foreign object (failed oil filter component theory) wouldn't likely be removed by flushing.

Two options to consider:

1) Have the shop replace that head. Rebuilt piece, or a good used one. Lower cost, but higher risk...the obstruction could be in the block's passage, and would still be there.

2) Install a used engine from LKQ that includes a bit of warranty time.

LKQOnline

Thanks waypoint. I'm really leaning toward the less risky path of replacing the engine. I see mixed opinions here concerning used vs rebuilt; I suppose there are good arguments for both. Any experiences out there with either one?

I bought my SR5 knowing it had an oiling problem. First owner leased it for 89,000 and never changed oil. Dealer sold it without changing the timing belt . The second owners changed the oil regularly until 154,000 then sold it when the oil light began flickering. Drop the lower pan and look for sludge. If it has it don't even think about keeping the engine. The front cam bearing oil passages are small and they will clog. No amount of cleaning will clear it out. If it's ok, just change the head.
First picture is the pan, the second is the cam bearing.

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I rebuilt mine after going to dealer and confirming that literally every year of 2uz-fe is different. If you get a new engine it has to be from the exact same year or you are screwed. I got one quote for 8900, one for 10000 and one shop who had done it before told me to turn around and walk out. The 2uz-fe is the most complicated engine to rebuild that most shops will ever see and the only reason that I was able to do it at all was because I have access to a Toyota dealer's computer system, a PC with my own hacked copy of techstream and the dealers master tech.

So, I have literally done what you are about to do, it took a long time, lots of tools and me buying engine parts from ebay for the exact same year to get everything to fit. Having the techstream PC was a lifesaver during the rebuild, it seems like the 2uz is a computer system with some arbitrary metal pieces attached for show.

Thx for the pics! My mechanic has been into the heads a couple of times now and always comments on how clean everything looks in there. I suppose I could ask him to check the oil pan as well, but with regular oil changes every 5-6K miles with Mobil 1 since it was purchased new, I don't expect him to find much sludge, but I could be wrong.

Just an FYI, I'm sure your mechanic will know this or he will figure it out, but there are 2 oil pans on the V8, the main big oil pan and a very small oil pan on the big oil pan, the small oil pan is the one Duffdog is referring too and it's very easy to remove and put back on, so an easy job for your mechanic to do for a look see, the main oil pan is not so easy to remove without a lot of work.

Got a 70k V8 from LKQ for $700 and it was spotless. I had a performance shop install for 1500.00 without issues.

Now that's a number I can live with! Did you get any sort of warranty with that?

Best I could find on LKQ was a 4.7L with 122K for $2000. Came out of a 2008 Lexus 470. Not a lot of 4.7L's to pick from out there so I jumped on it. Here we go...

Circling back to the original engine problem, would putting a higher pressure bypass spring in the oil pump do any good?

It won't correct an obstruction in an oil passage. There's nowhere for whatever's stuck to exit.

As mentioned, not if it's obstructed. The oil pump is not easy to get to also. Have you tried an oil pressure gauge to see what it's really putting out? I added one which is the only way I knew my pressure bypass was sticking open aside from a flickering light. That engine flush stuff I mentioned fixed that issue.