???CEL???P0507???

[Durs845]

alright so my check engine light kicked on a while back , thought i had a cylinder misfire before scanning it so i went ahead and installed new plugs , wires , fuel filter , and air filter since i didnt know when or if any of this had been done.shortly after this my battery died so i replaced that , which reset the CEL.after a couple of warm up cycles the CEL returned , i scanned it and it came up with the code P0507 idle control system RPM high.so i guess the question is any thoughts of what could be causing this or how to correct the problem?this is the link to what i could find out about this code:

http://glasairproject.com/soobdocs/codediag/P0507.gif

[jmgtp]

It is probably either a faulty idle air controller (IAC) or a vacuum leak which allows unmetered air into the system causing the high idle condition that tripped the code.

Before throwing money at it by buying an IAC check all vacuum hoses for cracks, breaks loose or broken connections. With the car running spray some carb cleaner around the intake manifold gaskets and throttle body gasket (don't go too crazy with it), if the idle changes you have a leaky gasket.

[Durs845]

alright so today i got around to trying to figure out whats goin with this code.i checked the air intake system , the throttle cable , and the air by pass line everything seems to be in order and operating the way it should be.my next step was to pull the 2 vacuum lines off the IAC and clean them out , when i did this i noticed that there was coolant in one of the lines which has me concerned ...IS THIS A SIGN OF A BLOWN HEAD GASKET??? i dried the 2 lines out put everything back together and started it up , now while idleing it revs constantly from 1800 RPM to 2200 RPM.which in my mind tells me the IAC is no good.has anyone out there had any similar problems????

[jmgtp]

Even if you had a blown head gasket I don't see how coolant would make it to the throttlebody or even to the intake manifold really. In such a case the coolant would either be expelled externally, drawn into the combustion chamber or mixed in the oil.

That said, are you absolutely sure that the lines you pulled were vacuum lines and not the coolant lines used to heat the throttlebody?

Maybe try unplugging the IAC. If the idle settles on one spot rather than rev awkwardly perhaps that could confirm a faulty IAC. I'd still check intake manifold gaskets with carb cleaner first. A $2 can of carb cleaner is a lot cheaper than an IAC.

[Durs845]

when i unplug the IAC the cars idle continuously drops till it stalls out , which then kicks a code P0505 (idle control system malfunction).

[Durs845]

there are 3 rubber lines off the IAC the bigger 1 which is the air by pass line and 2 smaller lines one on each side which i believed to be vacuum lines ( i could be wrong ) .the 1 on the left side when i pulled off had coolant in it.

[Durs845]

id hate to keep harping on this but ....its normal for coolant to pass through the IAC ????