Xterra 3.3 lifter noise after warm

[OpossumCop]

Hi all,

Posted on another site, but no real useful information there. Hopefully someone can assist here.

I recently replaced the engine in my 2004 Xterra. It's a VG33E, 3.3 non-S/C. I've been working on cars since I was a teen, and I did work at a shop for some time. I'll admit, I'm used to wrenching on hot rods and custom cars...Anyhow the previous engine was on its last legs (bad rings, bad valve stem seals, timing belt etc), and it was better financially to purchase a long block and do a swap, instead of rebuilding my existing engine which we normally do.

So, the swap went relatively smooth, albeit several days longer than expected, except for a few minor hiccups (one new fuel injector needed + new o-rings/gaskets for injectors, few trouble codes needing addressed, etc). She's running pretty well currently, except: The lifters are noisy after the engine is warmed up.

I admit I did re-use the oil pickup gasket since the one in the gasket kit that came with the long block wasn't OEM style. I installed a good oil pressure gauge to see what I was at, and at idle was up around (in park, in idle) 65-70psi when cold, then would drop to about 3-5psi when warmed. I did just replace the pickup gasket with an OEM Nissan, and O-ring. I'm now at 65 cold, and about 15 warm, which I read should be in spec.

However, i'm STILL getting lifter noise at operating temp. Appears to be more on the right side but both are making noise. I have another OEM gasket for between the oil filter bracket and block that I may replace as a last ditch effort, but I'm not sure why the lifters are so noisy even within spec oil pressure.

Any thoughts or opinions on this would be great. Otherwise, since I have pressure I'm driving it. Thanks for your time

[OpossumCop]

Update, but still looking for some input if possible.

Replaced gasket between oil pickup tube/pump with a new OEM gasket direct from Nissan as well as an o-ring. Did not install new gasket between pump/filter bracket yet.

New items seemed to help, but lifters still noisy at operating temp. Initially gauge was reading around 9psi @ idle. Now, pressure gauge is reading around 2 psi @ idle, around 750-800 rpm (while in drive). Goes up to around 5-6 while idling in park/neutral.

Next step is contacting the rebuilder of the engine...

Anyone heard of one of these 3.3 oil pumps being bad "out of the box"?

[jbracy7]

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