Coolant passage coming out of the head below the intake runners.

[KINGPIN33]

I was reading up on the online TSRM website and it mentioned this:

This was taken from the site:
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Intake Coolant Hose Leak

The coolant line that goes to the TB and ISC comes out of the head at the bottom of the intake runners. If the seal isn't good it could leak into the intake runners.
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What seal are they referring to? I almost 90% sure i'm burning coolant as I smell it and the car smokes during idle, but after driving away its gone... So I'm thinking its some small leak possibly a crack somewhere causing this... I just did the HG too w/ ARPS, stock HG, Shaved head... I did the repair thoroughly basically or so I believe.

Another thing I found interesting was that this port differs from GE and GTE? on the GE head, that coolant port comes out of the head whereas the GTE it comes out of the block? I circled what I'm talking about in red below:

 

[JustAnotherVictim]

There is a hose that comes off the isc that you're probably looking for.
My first thought anyways.
It connects underneath the runners.

 

[jdub]

The lower intake manifold is actually the same for the Turbo and NA. The seal they are referring to is part of the lower intake manifold to head gasket....it's a raised ring of green viton I believe. It lines up with the nipple below the #2 runner and provides coolant to the ISC valve/TB loop. It is possible (but not likely) this seal could leak allowing coolant into the lower intake manifold at the #2 runner.

 

[mrnickleye]

I have read other threads about coolant leaks "in" the throttle body (corroded thru), and also in the ISC. Check these out thoroughly.

Also, I by-passed my throttle body and capped the fittings on it. I just put a splice in the coolant hoses, to keep it flowing.

 

[KINGPIN33]

I have read other threads about coolant leaks "in" the throttle body (corroded thru), and also in the ISC. Check these out thoroughly.

Also, I by-passed my throttle body and capped the fittings on it. I just put a splice in the coolant hoses, to keep it flowing.

Yea, my plan is to bypass those two pieces... Its a huge pain to reach at them hoses though. I can barely see them let alone reach them... Did you have to remove the TB/ISC to bypass?

 

[mk3some]

basic benefits of the coolant goin thru the throttle body is for heating up purposes i assume? really how much of an effect does it have to bypass the throttle body coolant passages?
Also, the only thing you have to do is connect the two lines that go to the TB?

 

[tookwik4u89]

The lower intake manifold is actually the same for the Turbo and NA. The seal they are referring to is part of the lower intake manifold to head gasket....it's a raised ring of green viton I believe. It lines up with the nipple below the #2 runner and provides coolant to the ISC valve/TB loop. It is possible (but not likely) this seal could leak allowing coolant into the lower intake manifold at the #2 runner.

JDub is right on, and it would be the first time I've ever heard of that happening, I would look elsewhere, pressure test it if you can.

 

[KINGPIN33]

JDub is right on, and it would be the first time I've ever heard of that happening, I would look elsewhere, pressure test it if you can.

I did a compression test awhile ago and my cylinders read pretty good with no signs of a BHG... i followed that TSRM site procedure for compression testing. I really need to pressure test my coolant system... I suspect there HAS to be some small crack somewhere seaping and burning.

Upon inspection last night of my spark plugs, they were pretty black. quite a bit of carbon build up... Not sure why, I've got a new 02 sensor, new bov and I checked for boost leaks... new spark plug wires... timming is right. Not sure what else is screwy.

 

[CPT Furious]

I think 2Kwik is referring to pressure testing the cooling system itself. With the motor off, the pressure tester will force the coolant out of the leaking spot without the added distraction of having the motor running.

Also, be sure to thoroughly clean both the intake manifold surfaces and head surfaces before bolting them back together or that little hole will leak like a B*TCH!!! Two guesses how I figured that out...

 

[mrnickleye]

The ONLY reason the throttlebody is heated is for better emission control on a cold engine. Once the engine is at normal temp, it does not help lower emissions.

You want "cold" air going into the engine for more HPs. I noticed a bit more throttle responce when I by-passed the throttlebody.

Just pull the 2 hoses off and hook them together with a vacuum hose splice from the parts house.

Do the same with the ISC if you like. I left that alone, as only a small amount of air passes thru it, and I never got around to messing with it.

 

[RedDogOIF]

I just bypassed my hoses on Sun. I don't live in freezing temps so I figured I would rather have the extra HP insted

 

[mrnickleye]

The temps here have been from 15-20* F at night. 50-60*F daytime.

I love driving my car in the winter here, as it gains what feels like 15hp due to the cold air.

Car runs same without coolant to throttlebody, summer or winter, smooth as a babies ass.:biglaugh:

 

[drjonez]

The ONLY reason the throttlebody is heated is for better emission control on a cold engine. Once the engine is at normal temp, it does not help lower emissions...

nope. it's mostly to prevent freeze up in frigid conditions.

as for the coolant passage coming out of the head there, i plugged it.

 

[mk3some]

So that coolant hose going from the pipe in back (and side of the intake underneath) goes to the fitting facing down from the throttle body, then it goes through to the isc valve and from there ?
does it go right to the threaded fitting underneath the intake into the head? it looks like the correct size for that coolant hose...
so let me get this straight, i can basically connect that pipe to the threaded fitting and have no problems...??
those hoses are a pain in the ass to change and they are molded and you cant use frikkin straight hose and get it to work without kinkin! ooo kinkin

 

[RedDogOIF]

Connect them to each other under the TB with a connector you can get at any autstore. The holes in the TB can be plugged if u want, just be innovative I guess.

 

[mk3some]

Connect them to each other under the TB with a connector you can get at any autstore. The holes in the TB can be plugged if u want, just be innovative I guess.

cant i just take out the whole section of line? im replacing that coolant hose that goes up to the throttle body, i want to bypass it and find its final location even after the isc valve, im making sure that its the threaded fiting going into the head where the hoses all endup flowing to

 

[drjonez]

look @ the diagram in the first post.

you can simply run a hose from the nipple on the lower intake manifold over to the return pipe, thereby bypassing the TB and ISC.

 

[mk3some]

look @ the diagram in the first post.

you can simply run a hose from the nipple on the lower intake manifold over to the return pipe, thereby bypassing the TB and ISC.

thank you Dr., very simply put and i appreciate it, that is what i was talking about tho thanks for the clarification sir