IACV gasket leaking coolant

I'm having trouble with the idle air control IACV. Cleaned up whole sensor and surrounding area. Bought new idle air gasket from Carroll & roche and put it in. Turn engine on and idle is running way higher than normal, also white smoke and then idle drops right down like engine is struggling and check engine comes on with warning about idle air. So the stupid gasket is leaking coolant into the intake. Take the whole thing apart and buy loctite black gasket sealant and smother the area in it as well as putting the official gasket back in and try again, leaving it 24 hours to set. Then i try starting engine again and guess what - the same thing - white smoke, idle creeps higher towards 2k then drops right down and get idle air check engine light. So it looks like i won't be doing NCT on Monday Looks like IACV is broken/stuck and don't know why original gasket and loads of liquid gasket still leaks into intake - makes no sense. Anyone know how much a new IACV valve assembly costs?

I've never done a Subaru IACV but most have a butterfly or spring valve that can become stuck with gunk and you need to take the whole thing apart to clean it properly and free it up.

On the couple cars I've done, I've found that there's always one or more screws with a special key so I've had to either cut it out and replace with my own or if there's room I've taken a vise grips to it.

As for the white smoke that could just be remaining fluid in the intake. A bit of a spin after a proper clean will sort it.

[quote author=Bonito link=topic=35756.msg409872#msg409872 date=1348943724]
I've never done a Subaru IACV but most have a butterfly or spring valve that can become stuck with gunk and you need to take the whole thing apart to clean it properly and free it up.

On the couple cars I've done, I've found that there's always one or more screws with a special key so I've had to either cut it out and replace with my own or if there's room I've taken a vise grips to it.

As for the white smoke that could just be remaining fluid in the intake. A bit of a spin after a proper clean will sort it.
[/quote]

Yes on the black plastic section that contains the actual solenoid that attaches to the metal there are two Torx plus secure screws - these are 5-point star instead of normal 6-point Torx so no screwdriver works. I have ordered a plus secure Torx driver kit but it won't be here for a few days.

I suppose I'll wait until it comes and try and clean inside the black plastic section without removing the main metal bit which should be sealed down now with the gasket liquid. Still get the feeling there's more coolant getting into the intake though and not just left over from previous gasket attempts..

Yeh same ones myself and Baz came across when doing my Integra but we cut them out and replaced with nuts and bolts he had. Contacted Honda and all and nobody could give us a lend of a bit to fit them because you've to buy the whole throttle body if the IACV goes.

It'd be worth your while to take the whole throttle body apart and clean it. Use a bit of petrol to clean it with some cotton buds and give the whole thing a good work over with WD40.

On searching the Subaru forums an ECU reset may be needed sometimes but I dunno how that'd work with your ECUtek.

http://forums.nasioc.com/forums/showthread.php?t=781242

Yes that's the NASIOC forum thread i looked at before I did the clean - that's how I knew to have a new gasket beforehand.

I did clean the inside of the throttle body as good as i could (it was clean enough anyway) by removing the intercooler and spraying/wiping with throttle body cleaner while holding the throttle plate open myself.

Didn't actually take the throttle body off because couldn't get to bolts with the large tube from intercooler in the way - it seemed too tight to remove from throttle body so i left it. Also afraid of more gasket trouble between throttle body and engine.

I hope if IACV goes on Subaru you don't have to buy the entire throttle body

FYI. I finally opened up the idle air control valve there a few weeks ago - it was actually stuck solid - had to use vice-grips to release it and then oiled it up well so it can spin freely. Used special five-point Torx security kit I had to special order to open the secure Torx screws on the idle-air. This is available if anyone wants to use it to open and clean their IACV...