Auto WRX MY00 Hesitation

[MY00REX]

Hey all,

" Yes I have thought about a manual conversion or selling it and buying a manual GC8 "

I have a Stock GC8 WRX with Automatic Transmission, the issue seems to be fairly common with it now but has been otherwise fantastic.

The GC8 seems to bugger around when trying to accelerate hard as in overtake or speed up to merge onto the highway. I especially notice this when I'm travelling between say 50-60kph and in say 4th gear, I will put my foot down flat to the floor and it will lazily go into 3rd and just let the car range out slowly. Other occasions it will just drop into 2nd or even 1st if speed is low enough and takes off like a rocket.

This has been taken into a reputable shop and numerous people I would consider to be smarter than I with these cars, I have been told this is normal Auto stuff. I have owned the car for more than long enough to know something is different.

No codes are being stored and I have reset the ECU ( which the car runs great for a while then picks up this crap again ) replaced the MAF, Knock Sensor, Spark Plugs, I have had the TPS, PCV, among other items checked and cleaned, I have no boost leaks, The gearbox has been checked at said shop and have been told its fine, even installed a TBE to see if a cat had collapsed or something ( TBE back off car now ).

I am sure I am missing things I have checked, replaced, cleaned etc etc etc, I suspect the Knockdown but can find almost no info about it, so I am at a loss here and would like some info or direction as to what this may be.

Thank you.

[mv75]

Get a transmission cooler. I got a mishimoto on mine and it's helped heaps with a slipping issue I had.

Also check it is in power mode and not winter mode.

[MY00REX]

Winter mode?

Yep the Power button always on.

[mv75]

When the little orange snowflake lights up on the dash and the car starts in 2nd gear. It's great for loose surfaces.

Also check the fluid condition and level, you need to have it warmed up and running to check the level.

These can be finicky things. The auto in my gc8 was a boss, it would slam through the gears real quick, it was great. But it still had some moments like you're having too and would be a pig.

But the auto in my gd is slow and before I got the cooler would be very slippy and hate to change gears. Still is a bit slow, but most of the slip is now gone. Plus, touch wood, I haven't had it cut fuel and throw a too much torque error since putting the cooler on either.

[MY00REX]

Thanks mv75,

Looking into a cooler now, probably get it this week.

The fluid in the box seems fine, I changed only a week or more ago.

If I manually go through the gears the car is fine, also if I put it into 3rd and stand on it, the GC8 will drop into 2nd or 1st depending, I'm not sure if that's good or not, so I haven't let that happen anymore.

When the cooler shows up I'll install it, reset ecu, test drive and see how it goes. Hopefully no fuel cut.

[mv75]

Yea, D (4) is the overdrive. You'll get it going to 2nd if left in 3rd. These are learning transmissions too, if you have a lot of regular driving it'll be hesitant to then go into a quick mode until you do it a few times. I'd say that's where most of the issue is.

I hated the fuel cut, it did it on onramps when I was giving it to it, the car suddenly jerks and almost stops, lights up the dash, then continues.

[MY00REX]

I have read through this forums and others on the web about the Transmission picking up horrid habits. It is my daily and it would not shock me if it has adopted a very chill attitude to driving, but i thought still trying to plant it would result in the GC8 heading for optimal performance.

I have also read that its best to reset the ecu, then drive it like a feral to force the car into an aggressive state, this also met fierce resistance from numerous other WRX drivers, so I'm on the fence about that tactic.