throttle body coolant hose bypass (and acceptable engine temps)? (2 Viewers)

[landcruiser3DP]

i've got a coolant leak that seems to be coming from above the starter and i think we tracked it down to the throttle body coolant hose. i think this hose serves to keep the throttle body from freezing up which i don't need right now?
anyway can i plug this here and pull the hose and drive it if this solves the leak?
any idea what size cap i need? can i use this constant clamp and the rubber cap i used at this location at the firewall? do i need to get some kind of special high pressure cap?
i've got some 1/2" and 5/8" gates hose and some hose clamps in my spares.
also is there an engine temp or an alarm i can set for the ultra gauge beyond which i need to pull over?
i think i will also drive it with the radiator cap off in the meantime.
THANKS

 

[CharlieS]

What I used was 5/16" (8mm) silcone caps and stainless worm clamps.

You could also bypass the throttle body with a length of hose.

That photo you posted isn't the location of the hose (on the firewall) - that looks like a rear heater pipe or something- the other end of the throttle body heater hose is on the side of the block forward of the PHH.

 

[landcruiser3DP]

What I used was 5/16" (8mm) silcone caps and stainless worm clamps.

You could also bypass the throttle body with a length of hose.

That photo you posted isn't the location of the hose (on the forewall) - that looks like a rear heater pipe or something- the other end of the throttle body heater hose is on the side of the block forward of the PHH.

thanks a lot charlie.
green is what i am capping though?
and red is what i was planning on taking off the rear heater delete to cap the green circle i guess is what i was asking. i wasn't sure if it would fit or i needed something heavier duty...

 

[CharlieS]

Maybe. As i recall, they are different sizes. The cap you need on the thermostat is 5/16". The 2nd row heater pipe caps I used were 5/8".

 

[Kernal]

Not sure what the question is but here's some info FWIW:

The capped off pipe on the firewall goes to the rear heater and that system uses 1/2" ID heater hose. The fatter hose above the capped off nipple is 5/8" and goes to the main/front heater core.

The hose circled in green goes to a pipe that wraps around to the left side of the engine. Follow that pipe and you'll get to another hose that goes to the TP. If you have a leak near the green circled area you may have a leak from the fat riser pipe that runs up from the Thermostat housing. There are three O-rings that seal that pipe and is an area known to seep coolant.

If you have a coolant leak somewhere around the Throttle body then it could be a short section of hose that runs from the TB to the small pipe near the front of the engine, or if a leak from the underside of the TB, it could be from a bypass hose that runs from the bottom of the TB over and down the left side of the engine and onto a short pipe nipple in front of
the PHH (are you familiar with the PHH?).

Personally I would not cap off the hose circled in green, replace what's leaking.

Try a search for terms like: bypass hose leak PHH replacement

 

[landcruiser3DP]

Not sure what the question is but here's some info FWIW:

The capped off pipe on the firewall goes to the rear heater and that system uses 1/2" ID heater hose. The fatter hose above the capped off nipple is 5/8" and goes to the main/front heater core.

The hose circled in green goes to a pipe that wraps around to the left side of the engine. Follow that pipe and you'll get to another hose that goes to the TP. If you have a leak near the green circled area you may have a leak from the fat riser pipe that runs up from the Thermostat housing. There are three O-rings that seal that pipe and is an area known to seep coolant.

If you have a coolant leak somewhere around the Throttle body then it could be a short section of hose that runs from the TB to the small pipe near the front of the engine, or if a leak from the underside of the TB, it could be from a bypass hose that runs from the bottom of the TB over and down the left side of the engine and onto a short pipe nipple in front of
the PHH (are you familiar with the PHH?).

Personally I would not cap off the hose circled in green, replace what's leaking.

Try a search for terms like: bypass hose leak PHH replacement

hi kernal.
thanks as always.
so the leak is above the starter here and originally it seemed to come from these two hose clamps (GREEN arrows) but i think these are transmission cooler lines maybe. we were able to see it leaking from further above (RED arrow).
someone was kind enough to send me a pic showing what i think is the throttle body coolant hose (circled in RED)?
i was thinking to cap the spigot (circled in GREEN) thinking i would cap off the throttle body coolant hose.
then i would tighten the radiator cap and drive it and see if it still leaked. i believe this spigot feeds the throttle body coolant hose which would only be used to prevent the throttle body from freezing.
from the sounds of it you are saying it could also be the PHH (also in the photo) or it could be two other hoses?
i attached two of the online diagrams since FSM seems kind of weak in this area. but i am not sure if ALL hoses that run coolant are shown here or if your other two can be seen here?
<pics to follow>

 

[landcruiser3DP]

hi kernal.
thanks as always.
so the leak is above the starter here and originally it seemed to come from these two hose clamps (GREEN arrows) but i think these are transmission cooler lines maybe. we were able to see it leaking from further above (RED arrow).
someone was kind enough to send me a pic showing what i think is the throttle body coolant hose (circled in RED)?
i was thinking to cap the spigot (circled in GREEN) thinking i would cap off the throttle body coolant hose.
then i would tighten the radiator cap and drive it and see if it still leaked. i believe this spigot feeds the throttle body coolant hose which would only be used to prevent the throttle body from freezing.
from the sounds of it you are saying it could also be the PHH (also in the photo) or it could be two other hoses?
i attached two of the online diagrams since FSM seems kind of weak in this area. but i am not sure if ALL hoses that run coolant are shown here or if your other two can be seen here?
<pics to follow>

pics

 

[CharlieS]

Somebody posted a very helpful FSM here and I grabbed this shot from it, and put blue boxes around the two hoses that go into and out of the throttle body heat nipples. You can just bypass the throttle body part with a length of hose if you think that is your issue. No caps required.

Yes, that thing you have marked "PHH?" is the Pesky Heater Hose. Green box in diagram below.

 

[jht3]

i don't think you'll want to cap the hose where it comes out of the T-stat. while yes, it does flow through the T-body, the other end goes back into the head or block somewhere. i'm not sure exactly how much engine cooling could be compromised by stopping the flow.

but maybe you could get away w/ it for a short time. i don't think your heater cap will work but instead need a smaller version. you might even be able to stick a bolt in the other end of the hose and clamp it down tight. clean up the leak area well, let it dry, and test.

if you haven't yet done the PHH, do that. i got it done in my driveway. it sucked but possible w/o removing anything. it was the cause of my not obvious coolant leak.
then there is the pesky throttle body hose you are suspecting. i haven't done that one yet, as I plan on tackling it when I pull the intake apart and I don't think it is reachable w/o doing that.

 

[landcruiser3DP]

Somebody posted a very helpful FSM here and I grabbed this shot from it, and put blue boxes around the two hoses that go into and out of the throttle body heat nipples. You can just bypass the throttle body part with a length of hose if you think that is your issue. No caps required.

Yes, that thing you have marked "PHH?" is the Pesky Heater Hose. Green box in diagram below.

View attachment 3416879

awesome. thank you charlie. i will try to find it. i'm thinking joey modified this maybe because he saw it was confusing to see separately but maybe i am wrong.
anyway, the hose at arrow 1 in BLUE goes to the spigot i labelled 1 in BLUE i think.
i can see rhere is a hose coming off the block at the RED arrow but i can't tell if it is the - well it looks like the hose at the ORANGE arrow? meaning the orange arrow showing the hose in front of the PHH is that hose #2 or hose with the orange arrow?
-
i think what j am saying if there are three hoses up there - and the block drain - if i cap off the hose at 1 this eliminates the hose at 2 (i think this is throttle body coolant hose) which allows me to narrow it down to PHH or block drain plug or the mystery hose at the end of the orange arrow.
-> also do the orange arrow and #2 connect?

 

[CharlieS]

The red arrow in your picture is the line that goes from the side of the block to the intake heater (the line immediately to the right of it, aft - is the PHH). The line out of the intake heater goes to a metal pipe. The metal pipe wraps around the front of the engine and is connected to the thermostat housing at your blue "1" with another short hose.

If you want to route the coolant flow and the hoses in the most simple way and bypass the throttle, just run a 5/16" heater hose where I show the teal line below. From the side of the block to the metal pipe.

 

[landcruiser3DP]

i don't think you'll want to cap the hose where it comes out of the T-stat. while yes, it does flow through the T-body, the other end goes back into the head or block somewhere. i'm not sure exactly how much engine cooling could be compromised by stopping the flow.

but maybe you could get away w/ it for a short time. i don't think your heater cap will work but instead need a smaller version. you might even be able to stick a bolt in the other end of the hose and clamp it down tight. clean up the leak area well, let it dry, and test.

if you haven't yet done the PHH, do that. i got it done in my driveway. it sucked but possible w/o removing anything. it was the cause of my not obvious coolant leak.
then there is the pesky throttle body hose you are suspecting. i haven't done that one yet, as I plan on tackling it when I pull the intake apart and I don't think it is reachable w/o doing that.

hey. i really appreciate it. i think the goal is to putter around with coolant in it - it's not leaking with the rad cap cracked - and then drive an hour and a half or two hours to get the radiator done in a proper garage (and not in the dirt where i am now).
this is kind of like capping it. i can hack it up but i don't have stands or cribbing and i think i want to take the tire off to do it.
do you know if the red arrow on the photo of the block is the orange arrow in the diagram?
does anyone know if orange arrow and 2 connect or are part of the same circuit? or does anyone have a pic of this "other" hose? it connects to the block?

 

[landcruiser3DP]

The red arrow in your picture is the line that goes from the side of the block to the intake heater (the line immediately to the right of it, aft - is the PHH). The line out of the intake heater goes to a metal pipe. The metal pipe wraps around the front of the engine and is connected to the thermostat housing at your blue "1" with another short hose.

thanks man. so the orange one here is what i see in the pic of the block at the red arrow. then there is some connection at the block or intel heater that runs to that sligo at the tStat?
what's the intake heater do please?

 

[jht3]

yes, your orange arrow and red arrow are the same hose. you seem intent to block that hose off, so go and do it. find a cap at the parts store and clamp it down tight. stick a bolt up the other side and clamp that too. drive around.

i replaced my radiator in my driveway. no need to remove tires. i did pull the drivers tire to do the PHH. but you do you.

 

[CharlieS]

There is a combination of three hoses, the hard line through the throttle body, and another pipe (hard line) that wraps around the front of the block in that coolant flow between the block and the thermostat housing. You seem intent on blocking it off at the thermostat housing - yes, you can do that with a 5/16" cap and clamp. Then you need to figure out where to block off the other end. If you want to eliminate all of the potentially leaking hoses and pipes, you can cap it at the side of the block. Or you can block it at another point, if it suits you.

I'll get the details wrong, but the heated coolant circuit through the throttle body is to prevent icing of the throttle body.

 

[Somebodyelse5]

Dude, go to whatever auto parts store is near by and buy some heater hose, cut it, hose clamp it.

it's not leaking with the rad cap cracked

It's as if your cooling system gets pressurized or something...

More Pressure = Higher boiling point

Don't drive more than a few minutes without your radiator cap on. Your coolant will boil and evacuate through the open radiator. Your attempt to stop a small leak now became the way you overheated your engine.

 

[landcruiser3DP]

Dude, go to whatever auto parts store is near by and buy some heater hose, cut it, hose clamp it.

It's as if your cooling system gets pressurized or something...

More Pressure = Higher boiling point

Don't drive more than a few minutes without your radiator cap on. Your coolant will boil and evacuate through the open radiator. Your attempt to stop a small leak now became the way you overheated your engine.

thanks. sorry i am trying to wrap my head around it. i need to drive it to get the radiator and hoses put in. i also am supposed to help out family while here. so i'm trying to just make sure i'm tracking.
1. someone suggested loosening the radiator cap so it is not tight to get it into town (1 1/2 away). and just fill it if it gets low.
2. someone else said i can't rely on the ultragauge engine temp reading if there is air in the lines. so i thought i would burp it before going into town.
3. then someone said i could just cap it at the thermostat.
4. would be to try to get to the hoses via the top or to jack it up and take off the tire.
-
3 is easiest because i can just buy the parts and cap it right in front. but i can't tell if you are saying i can cap it there and/or if i need to cap it elsewhere as well? if i can do 3 it's easiest and i do all new hoses at a shop wirh a new radiator.

 

[77mustard40]

I’ve done that hose, not as difficult as the PHH but not exactly straight forward like most other hoses. IIRC I had to remove the throttle body to get to the other side of the hose where it tees into the head.

I’d replace it and be done with it as opposed to capping and hoping it doesn’t bite you later.

 

[Somebodyelse5]

Dude, go to whatever auto parts store is near by and buy some heater hose, cut it, hose clamp it.

thanks. sorry i am trying to wrap my head around it. i need to drive it to get the radiator and hoses put in. i also am supposed to help out family while here. so i'm trying to just make sure i'm tracking.
1. someone suggested loosening the radiator cap so it is not tight to get it into town (1 1/2 away). and just fill it if it gets low.
2. someone else said i can't rely on the ultragauge engine temp reading if there is air in the lines. so i thought i would burp it before going into town.
3. then someone said i could just cap it at the thermostat.
4. would be to try to get to the hoses via the top or to jack it up and take off the tire.
-
3 is easiest because i can just buy the parts and cap it right in front. but i can't tell if you are saying i can cap it there and/or if i need to cap it elsewhere as well? if i can do 3 it's easiest and i do all new hoses at a shop wirh a new radiator.

1. This is what I would do. Top it all off. Carry plenty of extra, distilled water is fine for this. This really depends on flow rates.... how much is leaking and how fast. I still want to emphasize that that if it's just a bad hose, you can spend $5 at autozone and get a similar size hose and fix this in 5 minutes.
2. If there is air at your temp probe you are having a really bad day. Air in cooling system is bad.
3. I wouldn't do this. Same effort to just replace the hose. Seriously, just replace the hose.
4. Stop what's leaking, then take it to the shop and have them do it while the cooling system is drained.

 

[ChargedSHOTaco]

Off topic, but I have never seen my intake air temps at 71 degrees after the engine has warmed up. It's always above 100. WTF?