Hiyo.
Background; Putting together a 3.4 into a 95 4runner. The 3.4 is from a 1999 4runner (manual/4wd).
Finally got assembled and pretty much put into engine bay (after machine work etc way back during coronachan days).
Believe it was this last spring of 23 when I got to point to put coolant in. Managed to start it briefly, thought starter was stuck (turns out Clutch Start Cancel switch is hanging!. But NOT pulling dash back apart to fix that).
However after maybe 30 seconds discovered quite the puddle of oil (probly a good cup). I guess the looser that assembled it either 1)Forgot 2) oil o-ring on pump fell off/twisted. Probably safe to go with 3) Spazzed out.

In chasing that down, discovered traces of coolant which come from up above on rear. Rented a pressure kit, found first my top Outlet for radiator hose wasn't sealing. Oddly, it was 'warped'. flattened it, discovered leak still there. Maybe worse. The outlet had a casting flaw. cracked above bolt flange. Go figure. Replaced. So now can pump about 10 -12 psi into system, but will loose several pounds in maybe few hours. Remember other than the pump, motor has not run for longer than minute or two, so no natural pressure. Can't see any other bubbles at any connection (soapy water method).

Nigling doubts, so yesterday I pulled intake plenums. Found the coolant (about a quart actually) had ponded in the valley (flood better word). (Hope it didn't ruin new knock harness). The forward most bolt on even side closest to Number 2 was already rusting a bit. The intake manifold gasket is new (to my untrained eye does not appear damaged). Maybe its the bypass pipe. The heads were machined (albeit in 2020) so pretty sure they're flat. Guess I will procure a straight edge and check the lower plenum? Did see traces of dried red on top of manifold before removal.

Those bolts do not pass into a coolant cavity do they? Any thoughts?

Many thanks in advance.

 

Reckon I will update since post been seen by a few readers. Maybe sell some vitamin supplements as well?

I took the plenum gasket over to the dealer this week. Parts Mgr said it looked okay. I am 99.9% certain it is true 'yota brand.
She was going to get 2 in, and said they'd call when came in (they haven't yet) and I could compare.

I also ordered a new #2 or whatever bypass tube. (Thinking about drilling a hole in rear plate so I could snake a video jobber in to view).
Ordered a machinist edge - which is apparantly sitting on a USPS dock on break now for several days.
Plan is to check the heads (should be fine), check the intake plenum per se, and replace that tube.

Question for home gamers: My water jacket holes on the intake manifold gaskets have a very thin raised 'rubber' outline gasket. The intake runners also have a small raised part.
But I was wondering if I took a small amount of FIPG on either side and put around the one closest to #2 piston - where I think there was some coolant staining - if that would work or would it just help to create a vacuum leak?
Of course, then I'd probably have to do all six water passages, or at least the 3 on driver side. Which is side I suspect. With no hard evidence.

Thoughts?
As always, TIA

 

Update for future generations.
I went to local toy dealer, and eventually got ONE new intake gasket. Put that on, and system pumped up okay, but still leaked down.
Took manifold off again, and noted some wetness matching the gasket out line (this time on pass side). Much consternation, then decided "Don't over think this."

Back to dealer, got the other gasket they had ordered. Note the dealer suppllied gaskets had a sort of cardboard/paper looking material on either side of the middle metal part. And the rubber outlines of the water passages were a slight bit thicker than the gasket (to be expected, but could feel with my fingers). the other "OEM" was metal on either side.
Cleaned surfaces with acetone, reinstalled. Now pumped up to 14 lbs, and stayed there for over 1/2 hour. Calling it good.
Or maybe it just quit leaking because I finally made enough of a coolant mess on floor. Will deal with air pockets later I suppose.

My originally purchased OEM intakes (entire gasket set IIRC, but can not find any evidence of purchase - now a diff computer) were definitely diff than the ones dealer sold. Got a dealer 'discount', 70 some bux EACH, but failed to get from McGeorge or whomever which with shipping might have saved me 30$.