Ok,

The first pic is going to be the connection @ the front of the motor.
From there it goes under the plenum to the connection @ the firewall.
It turns into rubber again and goes to the right pic 2
Pic 3 is basically how it runs in Blue, nad the green is how you bypass, just remember to route the hose in such a way as to not get damaged either by heat or moving things.
When i had it apart me and my Pops could not figure out what Toyota had in mind here. It just turns into a hard line and goes under the plenum then turns back into rubber. It ran no different after we fixed it.

I saw no real benifit to the routing than just astetics.
Any old hands have a different take?

Like i said mine basically rotted thru a little pin hole at the elbow going up in back, solder seemed to work ok, not optomistic cause of the temp, it might be repaired another way but the hard line is only going to pop else where, so if a true repair is needed you should just pull plenum and bend up a new hard line to replace the exisiting one.

hope this helps

JMO

 

Thanks for the pics man but mines not leaking there..its leaking under the intake not planum I think anyways from what I can tell..sounds possible?

 

I do belive so. I would try a search or page thru the FSM and see what i can find on intake coolant paths.

Someone else here might know but i am relativaly new to the 3.0.

 

Mine is doing the same thing, sitting at a stop light on the way to work and I see smoke. I will be tearing into it today and see what I can find.

Chris

 

Hi there brand new here, no idea how old this post is but it seems most similar to what I'm experiencing. Upon start up I have no smoke, but for the first 10 or so minutes of driving, while stopped at a light it have smoke coming out near the right side of the firewall, basically off the header on the right side, nearest to the firewall that seemingly doesn't reach pavement, and disappears after driving 10 more minutes. Could this be that cross over pipe? I've replaced all of my heater core lines including the u shaped one, but as soon as I replaced the u line this smoke show appeared. Perhaps now that I have more pressure that cross over line pisses til the truck reaches operating temp? Also, my overflow line connected at the neck of the rad likes to drip as well, regardless of the clamp I have on there. Anyone replaced this with successful no leakage? Thanks! I'm sonny by the way, *shakes everyone's hand*

 

Mine was leaking at the plenum, front and back

 

This one had me stumped. I would park the vehicle and find a puddle of coolant on the ground directly under the firewall. What I found was a leaking heater hose. It is very hard to see. Crouch down on the passenger side and look between the firewall and intake manifold when hot. Have a good flashlight. This might be what you are looking for. I had to put coolant in every day.

 

I just finished repairing the coolant leak on my 1990 2 Door,4WD, 3.0 L , 5 SPD. I did not remove the intake to completed the repair luckily I have a pair of long needle nose pliers and a universal socket set. I purchased the hose at Advance Auto I found the one listed above ( A71359 ) was a little to big I ended up using part number ( 71348 ) which is also a Dayco hose For Carquest that Advance Auto carries. GO figure ??!!! I will try to attach pictures.

 

I wish mine would have been that easy, it was a major tear down to get the plenum off, but it's done.

 

Ok update on my coolant leak. The Leak has returned but it is not from the new hose. I have driving the 4Runner to work for a while now and about 2 days ago I noticed a puddle under her again. I pressure tested the cooling system and it is leaking but I can not tell from where now. I can only assume it is from the metal piping that the hose connects to. I will need to removed the intake for this one. I plan on removing the upper intake and blocking off the hoses going to the throttle body and pressure testing to confirm leak. I will post pictures again once I find it.

 

I replaced the ushaped hose and now I'm seeing 2 very small hoses coming from an area right beside it that have broken off. Do you know what this is?

 

Sigh ... if only your powers of description REALLY were much better than a photograph.

Is it the thermal Vacuum valve (TVV)?


Some on this site have successfully repaired the valve, but at $65 it's a close call.

 

One of the small hoses is running from this thjng my screwdriver is pointing at.

 

I am holding one of the hoses and it runs from beside the shaped hose to the thing my screwdriver is pointing at. Its a 94 3.0 (sorry new to sight)

 

Yes, it is. Look at the vacuum routing sticker under the hood.
The Evaporative (EVAP) Canister. http://personal.utulsa.edu/~nathan-b...76evaporat.pdf

 

I think I have found all my coolant leaks now, last one was at the heater control valve. it was leaking from the bottom where cable attaches to it. found coolant dripping from the screw. I guess internals were worn. replaced it as well as heater core hoses. System pressurized and temp gauge stayed a tick below the halfway point. I drove her to Ohio from Georgia and back with no issues thus far.

 

I see this is an older post, but last week my 95 3.slow (3VZE) began spewing steam at stops from the pass side firewall area.
It was the small "U" shaped hose spitting at higher RPM's onto crossover. Since I just had my entire intake off last summer and lost years off my life trying to re-route the maze of vacuum lines, I wasn't about to try that again.
A long set of 45 degree needle nose, and laying face down across the top of the engine to reach the crevice, got the offending hose off fairly easy. I picked up a coolant hose off the rack at the parts store and replaced it with hose clamps, although I made the "U" nearly twice as large so the bend wasn't as pronounced.
I did struggle with bleeding the coolant system afterwards nearly as long as it took me to replace the "U " shaped hose in the PITA spot.
palm ratchet came in handy as one hand is all that fits back there.
hope this helped someone.

 

I owned a 1990 4runner, put 365K on it before the water pump started to crap out and sold it. (sidebar guy who bought it fully restored it and it is still rocking of course, cuz 4runners never die!!!)

I bought a nearly identical one, same year just the second version with the spoare on a swing gate on the back vs the always rusted up chain hoist under. Both have the amazing 3z V6 engine.

Anyway, both had this issue, and yes it is possible to replace without spending the insane money for the genuine Toyota part or removing the plenum. As another user noted you just need to get very up close and personal with the top of the engine. They key tool is a very long pair of needlenose pliers, at least a foot long.

Trust me there will be cursing involved, but it's possible.

Thanks to this forum, I been reading it forever, and it has helped with many issues. I love my 90 4runners, this one with 209K on it might very well be my last car in this lifetime!!!!!!!