Lexus4321

Here's what the lake of oil looks like in the intake. I believe the PCV system is allowing too much oil to be sucked up out of valve cover, and it ends up in the intake causing sludge in the runners all the way down into head ports !!! I installed a catch-can between PCV and intake to help stop this.

The sludge will impact performance.

Lexus4321

Just an update. Today I checked the dipstick on the catch-can, it was quite full. The can is 300ml volume, and I dumped out about 200ml of oil.
Using my handy-dandy mini notebook where I record my service and/or fix items, I installed the catch-can in Oct 2020. So just about 1yr and the can was about 2/3 full.

Not sure if blow-by gases on pistons is causing this extra oil out of the PCV or not, but at least the catch-can is keeping most/all of the oil out of the intake.

chiph9

Another possibility is leaking valve guide seals. I will occasionally get a puff of blue smoke on startup.

Drips into the cylinder when the vehicle is shut off, and seeps around the rings into the crankcase.

Chip H.

Lexus4321

I don't have any smoke at startup. When I scoped the pistons they all looked very very clean, and plugs run clean. My next to-do is leak-down test on each cylinder.

Maybe at these miles there's more blowby gases pushing oil into PCV. I'll Blackstone the next oil drop and ask them to evaluate fuel in the oil.

RC300

Pictures of your catch can installed?

Lexus4321

Yes, here
https://www.clublexus.com/forums/gx-...catch-can.html

NTH

I’m not sure if 200ml in a year is normal for this engine but your set up looks very tidy. Source/vendor for catch can?

Lexus4321

I got a "oil catch can" from Amzon. There's a few of same item via different names.
Any oil in the intake is not normal. I suspect rings are worn (250kmi) and blow-by gas is pushing more oil into the PCV. My next UOA I will ask Blackstone to focus in on fuel in the oil.