I developed a coolant leak underneath the intake manifold on my B16a. It's a steady stream....
there are some coolant hoses under there but even with a mirror i couldn't see anythin. when
i pour water in the top radiator hose it immediately pees it out. i can see the stream but not the
location of the leak. any suggestions?

 

Your options are:

1) Water pipe O-Rings
2) Heater Hose
3) IACV Coolant Hose
4) Intake manifold gasket where the bypass hose loops to the thermostat housing
5) Bypass hose

 

thanks, can i get to all of those hoses without removing the intake manifold?

 

All except the intake manifold gasket. It may be much easier to replace some of them with the intake manifold removed.

 

OK, i dug into it after the sun began to set a bit. the leak was coming from the thermostat housing,
specifically from that smaller hole on the left in this picture. there wasn't a hose attached to it. I
don't understand how it wasn't leaking previously. did it have a plug that fell out?
Also: that coolant tube that runs under the intake is very corroded and must be replaced. What's it
called?
and lastly, (see next pic) a radiator hose press fitting is corroded to oblivion. it was a good
thing that i dug into it now instead of on the road.

apparently, the previous owner was running tap water and no antifreeze in this engine. there's a lot of
corrosion in the cooling system. is there a radiator flush that can dissolve the corrosion?

The more i dig into this free del sol the more that needs to be done.

 

That hose nipple broke off of the thermostat housing. You have two options:

1) Find another thermostat housing that looks JUST LIKE the one you have pictured.
2) Drill and tap the small damaged hole 1/8" NPT and install a 5/16" hose barb in it and re-install the thermostat housing.

Good luck.

 

i'll definitely drill and tap it and install another hose barb but there was no hose to be see that connects to it? does it go into that metal pipe? it's a gaggle of worms under there.

 

There should essentially be a "loop" of 5/16" heater hose that makes the trip from either the water pipe under the intake manifold (between the back side of the water pump and the thermostat housing) or the water pipe end of the thermostat housing as you have pictured. From there, it should go out to the inlet side of the IACV, then out of the IACV and into the inlet side of the bottom of the Throttle Body, then out of the throttle body and back toward the cylinder head... either coming back to the thermostat housing or terminating at the upper radiator neck on the side of the head. In many applications, this circuit includes passing through a water and air pipe manifold that includes the 3/8" breather hose between the valve cover and the intake inlet pipe. Without seeing your specific application and the combination of parts... you will have to use some common sense and figure this path out based on what you see. In some cases where an engine has some aftermarket parts installed or mix-matched OE parts, you can have an odd number of coolant ports for this circuit, and thus, one may need to be plugged... and two extra should be looped together.

 

thanks for the informative reply! i looked at it again this morning. there are two other hoses that snake off of the metal coolant tube and are both hooked up below the intake manifold. i felt around and there is no dangling hose without a matching port. YES. this is a 1.6 from an early 90's JDM Integra or so the story goes....I'm going to just tap and plug that hole. I'm guessing that the previous owner may have tried to plug it with some goop that didn't hold because there isn't a loose hose to plug into it. .....going out in a bit to work on it when the sun goes down. THANKS AGAIN!

 

Anytime.

 

I threaded a bolt in the hole with JB Weld. that will work.... one last question:
One of the hoses that went into the head (? can't remember) 2nd pic. that press fitting was badly rusted and
pulled out of the head. can i just get another and hammer it in? what is it called?

THANKS

 

I don't think you can buy that nipple individually from Honda... I would recommend drilling and tapping the hole and put an appropriately sized pipe plug in the new hole.

 

that's not going to be easy because it's about 1/2" bore. (see 2nd pic) if i could get one of those press-fit hose fittings, i'll glue it in with JB Weld if necessary.

 

I guess I didn't look closely enough at your second picture... I just thought the broken nipple and hose went where the broken nipple appears to be in your first picture (the small port on the far left of the thermostat housing). So where exactly did the damaged hose barb come from ?

 

it goes from the thermostat housing to the intake manifold as shown by the red arrows.
the rusted nipple was press-fitted into the manifold. I'm thinking about using some 5/8
copper tubing and JB Weld .

thanks

 

Yeah, that takes hose #3 and is a critical part of engine coolant flow from the water pump pipe to the head.

 

thanks for that diagram. it will come in handy. i found what i need on ebay. The LS Swap guys use them.
going to see if i can find it locally.
https://www.ebay.com/itm/143811633956

 

****** christ...stupid debate on running str8 water vs coolant...