December 16, 200619 yr 96 Subaru Legacy Outback 2.5 Just purchased the car seems to have an idling problem Here's the issue: (Idle problem is the same when car is cold or warm, makes no difference) Sometimes it will idle normal when you come to a stop. Sometimes it will idle at a very low RPM like it's almost going to stall but never does. The idle does not seem to flucuate either it idles normal or it idles low until you start moving again. When it's idling low and you start to take off again you get a slight hesitation when you hit the gas. Once when I was at a stop light the rpm dropped the lowest i've seen it and the AT Oil temp light flashed on once for about 1/2 second then went off, wondering if this means anything or if maybe it was just because the car was about to stall. Wondering if anyone has any ideas or suggestions? I was thinking replace air and fuel filter and then move on to plug and wires? But not sure if there is anything else I should look for
December 16, 200619 yr Another not totally uncommon issue with the 2.5L Phase I engine is carbon. I've had this happen a couple of times with my 97 OB. While my idle itself has never really been an issue, I get exactly what you describe when starting off. As you tip into the throttle (feather it), you get some hesitation. If you hit the gas a bit harder and send the revs right up to 1500 rpm or more, you won't even notice it. A motorvac treatment solved it for me. Over the counter stuff may not be good enough if the problem is too advanced. Another note - The second time this happened to me, the problem was being aggrevated by a weak O2 sensor. I did not have any CEL, but the sensor was "slow". A weak sensor will also cause the engine to run richer. My experience. Commuter
December 16, 200619 yr Author Dirty IAC. There was just a post recently about it so maybe you could search. I did a bunch of searching for IAC using different terms but havn't had any luck in finding this post, does anyone have a link to this post by any chance?
December 16, 200619 yr Try this http://endwrench.com/images/pdfs/ISCSpring04.pdf Yours will be different, this only goes back to 99 but it gives you an idea of what to do and what to use , you can also search the site http://endwrench.com/ Hope this helps SEA#3
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