Help.. car leaking coolant

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So I had to replace my heads  due to a bent valve which was not that bad.. anyways the replacement heads I had machined.. and so I went to put coolant in it and it seems to be leaking someplace at the rear but I really can't tell from where.. Does the back of the head (passenger side) have any openings for coolant?

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it's the hose that goes to the IAC however I'm not sure where that coolant line goes?

[idosubaru]

definitely need to let us know what engine - i think it's an EJ25D DOHC you're running?

 

it's probably the TPS, i don't think the IAC's have coolant lines?   the TPS has an intlet and outlet hose and the one that goes to the heater core line under the drivers side intake manifold is the one prone to rust and leak.  it's the one that goes under the a/c compressor and down towards the water pump and gets the bypass hose. 

 

have to pull the intake manifold to replace that line. 

 

another option is to simply bypass the TPS stuff and run new hose, might save time and cheaper.

 

the TPS doesn't need cooling lines anyway, i remove them as standard pratice on my daily drivers if i'm in there for something else because they're unnecessary, been doing it for years.  so remove the two hoses and cap them off or run them in a loop, etc. 

 

it's routed like this:

COOLANT SOURCE.......to....TPS INLET.....to.....TPS OUTLET.....to.......BACK TO COOLANT SOURCE

 

i skip the TPS stuff and just a run a one piece hose from COOLANT SOURCE (where it comes from) BACK TO COOLANT SOURCE (wherever it goes after the TPS).

less hoses, less clamps, more reliable.

 

you'd have to run hose from the water pump bypass back to that heater core hose.  you have a couple options, but i would probably attempt to cut the hose under the a/c compressor and see if you can attach a piece of hose there - then snake it under the intake manifold to the heater core.

[Fairtax4me]

The older IAC had a thermostatic valve which is dependent on coolant temp for proper opening. However, I've read about plenty of people ditching the hoses altogether and not having any problems.

 

Still, those hoses are a royal pita to replace. You can get them through Subaru for about $10 each. Some parts stores carry a Dayco replacement that will work as well, but they are difficult to find. At least it was around here.

 

Three hoses, one from the bypass pipe to the throttle body, one from the throttle body to the IAC, and one from the IAC to the crossover pipe under the manifold. The crossover to IAC, and bypass to TB hose are the same part number, so order two of those if you plan to replace all 3.

 

It is just barely possible to replace all three without pulling the manifold if you remove the IAC.

[idosubaru]

oh right duh - it could just be the hoses and clamps?

 

i was sort of assuming it was rust because that's what seems to come first around here for those hoses. LOL

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Yeah I just removed the IAC and got the hose back on from that location, 2nd time that hose got to me but not while I was pouring coolant in.