1998 Legacy GT 4eat dies randomly at idle

I've got a 98 Legacy GT wagon with the 4eat. Car has 280k miles. yeah, i know.

its had the head gaskets done, but i have no history on the transmission (could be original, could be rebuilt, could be replaced).

normally the car runs and drives great, however sometimes, like 1 out of 10 times, when you come to a stop it just dies. always starts right back up though!

i just removed the IACV and cleaned it and replaced the gasket, but this didnt seem to help.

through further troubleshooting i discovered that sometimes while stopped and idling normally in drive, if i shift it down to 1st, it will die or nearly die.

any ideas?

as far as i know it doesnt have any vacuum leaks, and there are no CELs (yet)

i would really like to get this thing fixed ASAP because I need to sell it and move on.

was considering having the trans flushed at the dealer just to rule out that possibility...

could it be related to the brake band? I was reading about that

it doesnt seem to have any problems shifting under normal driving/accelerating conditions

Don't know why, but for this: "was considering having the trans flushed at the dealer just to rule out that possibility..."

This is easy to do yourself; don't pay the dealership prices for that.

GL!

Don't know why, but for this: "was considering having the trans flushed at the dealer just to rule out that possibility..."

 

This is easy to do yourself; don't pay the dealership prices for that.

 

GL!

I dont have the tools to properly *flush* the fluid. Sure, I could drain and refill it, but that's not going to do as much as actually flushing the fluid. Sure, it costs more, but only about $80 more. The fluid alone is gonna cost me about $80 and the dealer will do it for $160 or so, and I don't have to crawl under the car and smell like transmission fluid.

Always start with the basics. Sounds like a fuel issue to me. Check your fuel pump, filter, and injectors out. Also go get your battery and alternator tested at Advance. They so it for free. Just precautionary measures here so you dont spend all this money on your tranny when it could be fuel of electrical.

The car otherwise drives fine. has good power, runs on the freeway great, its just under certain idle circumstances, it drops idle and sometimes dies. I should try to replace the IACV but I'm not fully convinced thats the issue, though its work troubleshooting i suppose

I dont have the tools to properly *flush* the fluid. Sure, I could drain and refill it, but that's not going to do as much as actually flushing the fluid. Sure, it costs more, but only about $80 more. The fluid alone is gonna cost me about $80 and the dealer will do it for $160 or so, and I don't have to crawl under the car and smell like transmission fluid.

I think most here will agree with me that flushing an old transmission like that is a terrible idea unless it has had regular flushes its entire life. You can create more problems than you'll solve by dislodging debris that otherwise wouldn't be an issue. You're supposed to change the filter, but if you ignore that, then draining the fluid is literally the same procedure and just as easy as draining the oil. Do what I did: Drain fluid, top off, drive a day, drain fluid, top off again. Only like 4-5 quarts drains from it each time. Ideally a third drain and fill would be a good idea but I was too lazy.

Also, don't assume your IACV is working fine just because the CEL doesn't come on for it. Subarus don't like to throw codes very often. My IACV has been acting up for over a year (stalling issues) and I've only ever gotten the CEL once in that time-frame... and this is after another year of tracking down the problem with NO CEL. Also check your MAF sensor. In my case, both went bad at the same time which meant diagnosis wasn't easy since I wasn't really expecting both to be bad.